Form 424B5 - Prospectus [Rule 424(b)(5)]

Share Name	Share Symbol	Market	Type
Seelos Therapeutics Inc	NASDAQ:SEEL	NASDAQ	Common Stock

	Price Change	% Change	Share Price	Bid Price	Offer Price	High Price	Low Price	Open Price	Shares Traded	Last Trade
	0.00	0.00%	1.28	1.30	1.33				0	00:00:00

Filed Pursuant to Rule 424(b)(5)

Registration No. 333-276119

PROSPECTUS SUPPLEMENT
(to Prospectus dated December 27, 2023)

380,968 Shares of Common Stock

Pre-Funded Warrants to Purchase 81,239 Shares of Common Stock

Up to 81,239 Shares of Common Stock Underlying the Pre-Funded Warrants

We are offering directly to investors 380,968 shares of our common stock, $0.001 par value per share, at an offering price of $2.46 per share and pre-funded warrants (the “Pre-Funded Warrants”) to purchase up to 81,239 shares of common stock at an offering price of $2.459 per Pre-Funded Warrant to purchase one share of common stock, in each case in a registered direct offering pursuant to this prospectus supplement and the accompanying prospectus and securities purchase agreement with such investors.

The Pre-Funded Warrants have an exercise price of $0.001 and, subject to certain ownership limitations described herein, will be exercisable immediately upon issuance and will expire when exercised in full. We are also offering the shares of common stock that are issuable from time to time upon exercise of the Pre-Funded Warrants.

We are offering the Pre-Funded Warrants to purchase shares of common stock (and the shares of common stock issuable from time to time upon exercise of the Pre-Funded Warrants), in lieu of shares of common stock, to investors whose purchase of shares of common stock in this offering would otherwise result in any such investor, together with its affiliates, beneficially owning more than 4.99% (or, at the election of such investor, 9.99%) of our outstanding shares of common stock immediately following the consummation of this offering. Each Pre-Funded Warrant will be exercisable for one share of common stock at an exercise price of $0.001 per share of common stock. The offering price per Pre-Funded Warrant is equal to the offering price per share of common stock, less $0.001.

In a concurrent private placement, we are also selling to the investors, for no additional consideration, a warrant to purchase two shares of common stock for each share purchased in this offering and for each share of common stock issuable upon exercise of Pre-Funded Warrants purchased in this offering (the “Common Warrants”). The Common Warrants have an exercise price of $2.21 and, subject to certain ownership limitations described herein, are exercisable upon issuance and will expire on the date that is five years following the date of issuance.

Our common stock is listed on the Nasdaq Capital Market under the symbol “SEEL.” On May 16, 2024, the last reported sale price of our common stock on the Nasdaq Capital Market was $2.34 per share (after giving effect to the 1-for-8 reverse stock split effected on May 16, 2024). There is no established public trading market for the Pre-Funded Warrants, and we do not expect a market to develop. In addition, we do not intend to list the Pre-Funded Warrants, nor do we expect the Pre-Funded Warrants to be quoted, on the Nasdaq Capital Market or any other national securities exchange or any other nationally recognized trading system. Without an active trading market, the liquidity of the Pre-Funded Warrants will be limited.

We have engaged Roth Capital Partners, LLC to act as exclusive placement agent in connection with this offering. The placement agent has agreed to use its reasonable best efforts to sell the securities offered by this prospectus supplement and the accompanying prospectus. The placement agent is not purchasing or selling any securities offered by this prospectus supplement and the accompanying base prospectus. See “Plan of Distribution” beginning on page S-29 of this prospectus supplement for more information regarding these arrangements.

As of May 16, 2024, the aggregate market value of our common stock held by non-affiliates pursuant to General Instruction I.B.6. of Form S-3 was $16,349,880, based on 2,226,776 outstanding shares of our common stock held by non-affiliates and a price of $7.3424 per share, the closing sale price of our common stock reported on the Nasdaq Capital Market on March 18, 2024 (a date within 60 days of the date hereof). The calculations in the previous sentence give effect to the 1-for-8 reverse stock split effected on May 16, 2024. During the 12 calendar months prior to and including the date of this prospectus supplement (excluding this offering), we have sold an aggregate of $4,000,000.80 of securities pursuant to General Instruction I.B.6 of Form S-3. As a result, we are eligible to offer and sell up to an aggregate of $1,366,050 of shares of our common stock pursuant to General Instruction I.B.6. of Form S-3.

Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page S-12 of this prospectus supplement and under similar headings in the documents incorporated by reference into this prospectus supplement and the accompanying prospectus for a discussion of certain risks you should consider before investing in our securities.

	Per Share			Per Pre-Funded Warrant			Total
Offering price		$	2.46		$	2.45900		$	1,136,947.98
Placement agent’s fees(1)		$	0.1722		$	0.17213		$	79,586.36
Proceeds to us, before expenses(2)		$	2.2878		$	2.28687		$	1,057,361.62

(1)

We have agreed to pay the placement agent a cash placement commission equal to 7% of the aggregate proceeds from this offering and the concurrent private placement. See “Plan of Distribution” beginning on page S-29 of this prospectus supplement for information about the placement agent’s fees and expense reimbursement and our estimated offering expenses.

(2)

The amount of offering proceeds to us presented in this table does not include proceeds from the exercise of the Common Warrants to be issued in the concurrent private placement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

Delivery of the shares of common stock and the Pre-Funded Warrants to the investors is expected to be made on or about May 21, 2024, subject to customary closing conditions.

Roth Capital Partners

The date of this prospectus supplement is May 16, 2024.

TABLE OF CONTENTS

PROSPECTUS SUPPLEMENT

	Page
About this Prospectus Supplement		S-1
Prospectus Supplement Summary		S-2
The Offering		S-9
Risk Factors		S-12
Disclosure Regarding Forward-Looking Statements		S-16
Market and Industry Data		S-18
Selected Financial Data		S-19
Use of Proceeds		S-21
Dividend Policy		S-22
Dilution		S-23
Description of Securities Offered		S-25
Private Placement Transaction and Common Warrants		S-27
Plan of Distribution		S-29
Legal Matters		S-32
Experts		S-32
Where You Can Find More Information		S-33
Information Incorporated by Reference		S-34

PROSPECTUS

	Page
ABOUT THIS PROSPECTUS		1
INDUSTRY AND MARKET DATA		2
SUMMARY		3
RISK FACTORS		10
DISCLOSURE REGARDING FORWARD-LOOKING STATEMENTS		15
USE OF PROCEEDS		17
DESCRIPTION OF CAPITAL STOCK		18
DESCRIPTION OF DEBT SECURITIES		23
DESCRIPTION OF WARRANTS		32
DESCRIPTION OF UNITS		36
DESCRIPTION OF RIGHTS		37
LEGAL OWNERSHIP OF SECURITIES		38
PLAN OF DISTRIBUTION		41
LEGAL MATTERS		43
EXPERTS		43
WHERE YOU CAN FIND MORE INFORMATION		43
INCORPORATION OF DOCUMENTS BY REFERENCE		44

S-i

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS SUPPLEMENT

This prospectus supplement and the accompanying base prospectus are part of a “shelf” registration statement on Form S-3 that we filed with the U.S. Securities and Exchange Commission (the “SEC”), using a “shelf” registration process. This prospectus supplement describes the specific terms of this offering. The accompanying base prospectus, including the documents incorporated by reference therein, provides general information about us, some of which, such as the section therein titled “Plan of Distribution,” may not apply to this offering. Generally, when we refer to this prospectus supplement, we are referring to both this prospectus supplement and the accompanying base prospectus, combined.

We urge you to carefully read this prospectus supplement, the accompanying base prospectus, the documents incorporated by reference herein and therein and the additional information under the headings “Where You Can Find More Information” and “Information Incorporated by Reference” before buying any of the securities being offered under this prospectus supplement. These documents contain information you should consider when making your investment decision.

You should rely only on the information contained or incorporated by reference in this prospectus supplement and the accompanying base prospectus. We have not, and the placement agent has not, authorized anyone to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus supplement may add, update or change information contained in the accompanying base prospectus. To the extent any information in this prospectus supplement is inconsistent with the accompanying base prospectus, you should rely on the information in this prospectus supplement. The information in this prospectus supplement will be deemed to modify or supersede the information in the accompanying base prospectus and the documents incorporated by reference therein, except for those documents incorporated by reference therein which we file with the SEC after the date of this prospectus supplement.

You should not assume that the information contained or incorporated by reference in this prospectus supplement and the accompanying base prospectus is accurate on any date subsequent to the date set forth on the front cover of this prospectus supplement and the accompanying base prospectus or on any date subsequent to the date of the document incorporated by reference herein or therein, as applicable. Our business, financial condition, results of operations and prospects may have changed since those dates.

We are offering to sell, and seeking offers to buy, the securities described in this prospectus supplement only in jurisdictions where offers and sales are permitted. The distribution of this prospectus supplement and the offering of the securities in certain jurisdictions may be restricted by law. Persons outside the United States who come into possession of this prospectus supplement must inform themselves about, and observe any restrictions relating to, the offering of the securities and the distribution of this prospectus supplement outside the United States. This prospectus supplement does not constitute, and may not be used in connection with, an offer to sell, or a solicitation of an offer to buy, any securities offered by this prospectus supplement by any person in any jurisdiction in which it is unlawful for such person to make such an offer or solicitation.

We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference into this prospectus supplement or the accompanying base prospectus were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

In this prospectus supplement, unless otherwise indicated or required by the context, the terms “Seelos,” “we,” “our,” “us” and the “Company” refer to Seelos Therapeutics, Inc. and its consolidated subsidiaries.

S-1

TABLE OF CONTENTS

PROSPECTUS SUPPLEMENT SUMMARY

This summary contains basic information about us and this offering. This summary highlights selected information contained elsewhere in, or incorporated by reference into, this prospectus supplement. This summary is not complete and may not contain all of the information that is important to you and that you should consider before deciding whether or not to invest in our securities. For a more complete understanding of Seelos and this offering, you should carefully read this prospectus supplement, including any information incorporated by reference into this prospectus supplement, in its entirety. Investing in our securities involves risks that are described in this prospectus supplement under the heading “Risk Factors,” under the headings “Item 1A. Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2023, our Quarterly Report on Form 10-Q for the quarter ended March 31, 2024 and in our other filings with the SEC.

Our Company

Overview

We are a clinical-stage biopharmaceutical company focused on achieving efficient development of products that address significant unmet needs in Central Nervous System (“CNS”) disorders and other rare disorders.

Our business model is to advance multiple late-stage therapeutic candidates with proven mechanisms of action that address large markets with unmet medical needs and for which there is a strong economic and scientific rationale for development.

Our product development pipeline is as follows:

Product	Indication	Development Phase	Development Status
SLS-002 Intranasal Racemic Ketamine	Acute Suicidal Ideation and Behavior (“ASIB”) in Major Depressive Disorder (“MDD”)	Phase II	Completed open-label patient enrollment and announced the initial topline data from Part 1 of the proof-of-concept (“PoC”) study on May 17, 2021; enrollment of Part 2 of a Phase II study closed in June 2023; topline data for Part 2 announced on September 20, 2023
SLS-005 IV Trehalose	Amyotrophic Lateral Sclerosis (“ALS”)	Phase II/III	Completed enrollment of final participants in February 2023 in the registrational study; topline data announced on March 19, 2024
	Spinocerebellar Ataxia (“SCA”)	Phase IIb/III	Announced dosing of the first participant in the registrational study in October 2022; enrollment of additional patients temporarily paused on March 29, 2023
	Huntington’s Disease (“HD”) and Alzheimer’s Disease (“AD”)	Phase II	Obtaining biomarker activity
SLS-004 Gene Therapy	Parkinson’s Disease (“PD”)	Pre-IND	Preclinical in vivo studies ongoing; announced partial results from a study demonstrating downregulation of α-synuclein in December 2022; currently analyzing data while temporarily pausing additional spend

S-2

TABLE OF CONTENTS

Product	Indication	Development Phase	Development Status
SLS-007 Peptide Inhibitor	PD	Pre-IND	Preclinical study completed and analysis of the results ongoing; next steps for development of this program will be decided in concert with SLS-004 results and readouts, as both target the same pathway upstream; temporarily pausing additional spend
SLS-009	HD, AD, ALS	Pre-IND	Preclinical in vivo studies ongoing

Lead Programs

Our lead programs are currently SLS-002 for the potential treatment of ASIB in adults with MDD and SLS-005 for the potential treatment of ALS and SCA. SLS-005 for the potential treatment of Sanfilippo Syndrome currently requires additional natural history data, which is being considered.

SLS-002 is intranasal racemic ketamine with two investigational new drug applications (“INDs”). The lead program is focused on the treatment of ASIB in MDD. SLS-002 was originally derived from a Javelin Pharmaceuticals, Inc./Hospira, Inc. program with 16 clinical studies involving approximately 500 subjects. SLS-002 is being developed to address an unmet need for an efficacious drug to treat suicidality in the United States. Traditionally, anti-depressants have been used in this setting but many of the existing treatments are known to contribute to an increased risk of suicidal thoughts in some circumstances, and if and when they are effective, it often takes weeks for the full therapeutic effect to be manifested. We believe there is a large opportunity in the United States and European markets for products in this space. Based on information gathered from the databases of the Agency for Healthcare Research and Quality, there were approximately 1.48 million visits to emergency rooms for suicidal ideation or suicide attempts in 2017 in the United States alone. Experimental studies suggest ketamine has the potential to be a rapid, effective treatment for depression and suicidality.

The clinical development program for SLS-002 includes two parallel healthy volunteer studies (Phase I). We announced interim data from our Phase I study of SLS-002 during the quarterly period ended March 31, 2020. As a result, in March 2020, we completed a Type C meeting with the U.S. Food and Drug Administration (the “FDA”) and received guidance to conduct a PoC study of SLS-002 for ASIB in adults with MDD, to support the further clinical development of this product candidate, together with nonclinical data under development.

As a result of the Type C meeting and the Fast Track designation for SLS-002 for the treatment of ASIB in patients with MDD, we believe we are well positioned to pursue the FDA’s expedited programs for drug development and review.

On June 23, 2020, we announced the final safety data from our Phase I pharmacokinetics/pharmacodynamics study of intranasal racemic ketamine (SLS-002) as well as the planned design of a Phase II double blind, placebo-controlled PoC study for ASIB in subjects with MDD. We initiated this PoC study in two parts: Part 1 was an open-label study of 17 subjects, and was followed by Part 2, which is a double blind, placebo-controlled study of approximately 175 subjects. On January 15, 2021, we announced dosing of the first subjects in Part 1 of the PoC study. On March 5, 2021, we announced the completion of open-label enrollment of subjects in Part 1 of the PoC study. On May 17, 2021, we announced positive topline data from Part 1 of the PoC study, the open-label cohort, of our study of SLS-002 (intranasal racemic ketamine), demonstrating a significant treatment effect and a well-tolerated safety profile for ASIB in patients with MDD. This study enrolled 17 subjects diagnosed with MDD requiring psychiatric hospitalization due to significant risk of suicide with a baseline score of ≥ 28 points on the Montgomery-Åsberg Depression Rating Scale (“MADRS”), a score of 5 or 6 on MADRS Item-10, a score of ≥ 15 points on the Sheehan-Suicidality Tracking Scale (S-STS) total score and a history of previous suicide attempt(s), as confirmed on the Columbia Suicide Severity Rating Scale (C-SSRS) with a history of at least one actual attempt, or if the attempt was interrupted or aborted, is judged to have been serious in intent. SLS-002 demonstrated a 76.5% response rate

S-3

TABLE OF CONTENTS

(response meaning 50% reduction from baseline) in the primary endpoint on MADRS twenty-four hours after first dose, with a mean reduction in total score from 39.4 to 14.5 points.

On July 6, 2021, we announced dosing of the first subject in Part 2 of the Phase II study. Based on feedback from a Type C meeting with the FDA in June 2021, we increased the subjects in Part 2 to increase the sample size and power to support a potential marketing application. On June 20, 2023, we announced the close of enrollment of this study and released the topline results on September 20, 2023.

SLS-005 is IV trehalose, a protein stabilizer that crosses the blood-brain-barrier and activates autophagy and the lysosomal pathway. Based on preclinical and in vitro studies, there is a sound scientific rationale for developing trehalose for the treatment of ALS, SCA and other indications such as Sanfilippo Syndrome. Trehalose is a low molecular weight disaccharide (0.342 kDa) that protects against pathological processes in cells. It has been shown to penetrate muscle and cross the blood-brain-barrier. In animal models of several diseases associated with abnormal cellular protein aggregation, it has been shown to reduce pathological aggregation of misfolded proteins as well as to activate autophagy pathways through the activation of Transcription Factor EB (“TFEB”), a key factor in lysosomal and autophagy gene expression. Activation of TFEB is an emerging therapeutic target for a number of diseases with pathologic accumulation of storage material.

Trehalose 90.5 mg/mL IV solution has demonstrated promising clinical potential in prior Phase II clinical development for oculopharyngeal muscular dystrophy (“OPMD”) and spinocerebellar ataxia type 3 (“SCA3”), also known as Machado Joseph disease, with no significant safety signals to date and encouraging efficacy results. Pathological accumulation of protein aggregates within cells, whether in the CNS or in muscle, eventually leads to loss of function and ultimately cell death. Prior preclinical studies indicate that this platform has the potential to prevent mutant protein aggregation in other devastating PolyA/PolyQ diseases.

We own three United States patents for parenteral administration of trehalose for patients with OPMD and SCA3, all of which are expected to expire in 2034. In addition, Orphan Drug Designation (“ODD”) for OPMD and SCA3 has been secured in the United States and in the European Union (“EU”). In February 2019, we assumed a collaborative agreement, turned subsequently into a research grant, with Team Sanfilippo Foundation (“TSF”), a nonprofit medical research foundation founded by parents of children with Sanfilippo Syndrome. On April 30, 2020, we were granted ODD for SLS-005 in Sanfilippo Syndrome from the FDA. SLS-005 was previously granted ODD from the FDA and European Medicines Agency (the “EMA”) for SCA3 and OPMD as well as Fast Track designation for OPMD. On August 25, 2020, we were issued U.S. patent number 10,751,353 titled “COMPOSITIONS AND METHODS FOR TREATING AN AGGREGATION DISEASE OR DISORDER” which relates to trehalose (SLS-005). The issued patent covers the method of use for trehalose (SLS-005) formulation for treating a disease or disorder selected from any one of the following: spinal and bulbar muscular atrophy, dentatombral-pallidoluysian atrophy, Pick’s disease, corticobasal degeneration, progressive supranuclear palsy, frontotemporal dementia or parkinsonism linked to chromosome 17. On May 15, 2020, we were granted Rare Pediatric Disease Designation (“RPDD”) for SLS-005 in Sanfilippo Syndrome from the FDA. RPDD is an incentive program created under the Federal Food, Drug, and Cosmetic Act to encourage the development of new therapies for the prevention and treatment of certain rare pediatric diseases. On May 27, 2021, we announced that we were granted ODD for SLS-005 in ALS from the EMA. In December 2020, we announced the selection of SLS-005 for the Healey ALS platform trial led by Harvard Medical School, Massachusetts. The Healey ALS platform trial is designed to study multiple potential treatments for ALS simultaneously. The platform trial model aims to greatly accelerate the study access, reduce costs and shorten development timelines. On February 28, 2022, we announced the dosing of the first participants in the Healey ALS platform trial. In November 2021, we announced the FDA acceptance of an IND and grant of Fast Track designation for SLS-005 for the treatment of SCA. In July 2022, we also announced dosing of the first patient in an open-label basket study in Australia for the treatment of patients with ALS, SCA, and Huntington’s disease (“HD”). In October 2022, we also announced the dosing of the first participant in the registrational Phase II/III study for the treatment of SCA. In March 2023, we announced that in order to focus the majority of our resources on the Phase II study of SLS-002 (intranasal racemic ketamine) for ASIB in adults with MDD and the fully enrolled Phase II/III study of SLS-005 in ALS, we have temporarily paused additional enrollment of patients in the SLS-005-302 study in SCA. Patients already enrolled will continue in the study and data will continue to be collected in order to

S-4

TABLE OF CONTENTS

make decisions for resuming enrollment in the future. This temporary pause has been implemented as a business decision due to financial considerations, and is not based on any data related to safety or therapeutic effects.

Additionally, we are developing several preclinical programs, most of which have well-defined mechanisms of action, including SLS-004, licensed from Duke University, and SLS-007, licensed from The Regents of the University of California, for the potential treatment of PD.

Strategy and Ongoing Programs

SLS-002: The clinical development program for SLS-002 includes two parallel healthy volunteer studies (Phase I). Following these Phase I studies, we completed a Type C meeting with the FDA in March 2020 and received guidance to conduct a Phase II PoC study of SLS-002 for ASIB in adults with MDD. We released topline data for Part 1 of our open-label study on May 17, 2021. We initiated enrollment in Part 2 of the Phase II study on July 6, 2021, closed enrollment in June 2023, and released the topline results in the third quarter of 2023.

SLS-005: We completed enrollment in February 2023 for a clinical study in ALS and began enrollment for a clinical study in SCA in October 2022. In December 2020, we announced the selection of SLS-005 for the Healey ALS platform trial led by Harvard Medical School, Massachusetts. The Healey ALS platform trial is designed to study multiple potential treatments for ALS simultaneously. The platform trial model aims to greatly accelerate the study access, reduce costs, and shorten development timelines. On February 28, 2022, we announced dosing of the first participants in the Healey ALS platform trial. In February 2023, we announced the completion of enrollment of the study and released the topline data results on March 19, 2024.

In November 2021, we announced the FDA acceptance of an IND and grant of Fast Track designation for SLS-005 for the treatment of SCA. In July 2022, we announced dosing of the first patient in an open-label basket study in Australia for the treatment of patients with ALS, SCA, and HD. In October 2022, we also announced the dosing of the first participant in the registrational Phase II/III study for the treatment of SCA.

During 2022, we received regulatory approval in Australia to commence a study pursuing the collection of certain biomarker data in patients with AD.

We are also continuing to consider trials in Sanfilippo Syndrome and are seeking more natural history data based on the guidance from regulatory agencies.

In March 2023, we announced that in order to focus the majority of our resources on the Phase II study of SLS-002 (intranasal racemic ketamine) for ASIB in patients with MDD and the fully enrolled Phase II/III study of SLS-005 in ALS, we have temporarily paused additional enrollment of patients in the SLS-005-302 study in SCA. Patients already enrolled will continue in the study and data will continue to be collected in order to make decisions for resuming enrollment in the future. This temporary pause has been implemented as a business decision due to financial considerations, and is not based on any data related to safety or therapeutic effects.

SLS-004 is an all-in-one lentiviral vector, targeted for gene editing through DNA methylation within intron 1 of the synuclein alpha (“SNCA”) gene that expresses alpha-synuclein (“α-synuclein”) protein. SLS-004, when delivered to dopaminergic neurons derived from human induced pluripotent stem cells of a PD patient, modified the expression on α-synuclein and exhibited reversal of the disease-related cellular-phenotype characteristics of the neurons. The role of mutated SNCA in PD pathogenesis and the need to maintain the normal physiological levels of α-synuclein protein emphasize the yet unmet need to develop new therapeutic strategies, such as SLS-004, targeting the regulatory mechanism of α-synuclein expression. On May 28, 2020, we announced the initiation of a preclinical study of SLS-004 in PD through an all-in-one lentiviral vector targeting the SNCA gene. We are constructing a bimodular viral system harboring an endogenous α-synuclein transgene and inducible regulated repressive CRISPR/dCas9-unit to achieve suppression of PD-related pathologies. On July 7, 2021, we announced positive in vivo data demonstrating down-regulation of SNCA mRNA and protein expression under this study. In December 2022, we announced in vivo data demonstrating that a single dose of SLS-004 was successful in reversing some of the key hallmarks of PD in a humanized mouse model. These findings observed in an in vivo humanized PD model validate and extend prior findings from in vitro data using SLS-004. SLS-004 demonstrated therapeutically desirable change

S-5

TABLE OF CONTENTS

in SNCA expression that led to reversing the key hallmarks of PD in the model towards normal physiological levels, indicating disease modifying effect of single dose administration of SLS-004, a CRISPR/dCas-9 based gene therapy for PD. We have halted any further investment in this program until additional funding is received.

SLS-007 is a rationally designed peptide-based approach, targeting the nonamyloid component core (“NACore”) of α-synuclein to inhibit the protein from aggregation. Recent in vitro and cell culture research has shown that SLS-007 has the ability to stop the propagation and seeding of α-synuclein aggregates. We will evaluate the potential for in vivo delivery of SLS-007 in a PD transgenic mice model. The goal will be to establish in vivo pharmacokinetics/pharmacodynamics and target engagement parameters of SLS-007, a family of anti-α-synuclein peptidic inhibitors. On June 25, 2020, we announced the initiation of a preclinical study of SLS-007 in PD delivered through an adeno associated viral (“AAV”) vector targeting the non-amyloid component core of α-synuclein. We have initiated an in vivo preclinical study of SLS-007 in rodents to assess the ability of two specific novel peptides, S62 and S71, delivered via AAV1/2 viral vector, to protect dopaminergic function in the AAV A53T overexpression mice model of PD. Production of AAV1/2 vectors encoding each of the two novel peptides incorporating hemagglutinin tags has already been completed. The results are currently being analyzed and the next steps for development of this program will be decided in concert with SLS-004 results and readouts, as both target the same pathway upstream.

SLS-009 is our first internally created program, which follows the mechanism of action known as PROTACs (protein-targeting chimeric molecules), which uses the body’s own natural process of autophagy and lysosomal degradation to clear out mutant and misfolded proteins in the body. SLS-009 induces autophagy and enhances lysosomal clearance by augmenting existing endogenous cellular degradation pathways to remove only the mutant and neurotoxic proteins.

We intend to become a leading biopharmaceutical company focused on neurological and psychiatric disorders, including orphan indications. Our business strategy includes:

•

advancing SLS-002 in ASIB in MDD and post-traumatic stress disorder;

•

advancing SLS-004 in PD;

•

advancing SLS-005 in ALS, SCA, HD and Sanfilippo Syndrome;

•

advancing new formulations of SLS-005 in neurological diseases; and

•

acquiring synergistic assets in the CNS therapy space through licensing and partnerships.

We also have two legacy product candidates: a product candidate in the United States for the treatment of erectile dysfunction, which we in-licensed from Warner Chilcott Company, Inc., now a subsidiary of Allergan plc; and a product candidate which has completed a Phase IIa clinical trial for the treatment of Raynaud’s Phenomenon, secondary to scleroderma, for which we own worldwide rights.

Nasdaq Delisting

On April 30, 2024, we received written notice (the “Bid Notice”) from The Nasdaq Stock Market LLC (“Nasdaq”) indicating that, for the last thirty consecutive business days, the bid price for our common stock had closed below the minimum $1.00 per share requirement for continued listing on the Nasdaq Capital Market under Nasdaq Listing Rule 5550(a)(2) (“Rule 5550(a)(2)”. In accordance with Nasdaq Listing Rule 5810(c)(3)(A), we have been provided an initial period of 180 calendar days, or until October 28, 2024, to regain compliance. The Bid Notice states that the Nasdaq staff will provide written confirmation that we have achieved compliance with Rule 5550(a)(2) if at any time before October 28, 2024, the bid price of our common stock closes at $1.00 per share or more for a minimum of ten consecutive business days.

If we do not regain compliance with Rule 5550(a)(2) by October 28, 2024, we may be eligible for an additional 180 calendar day compliance period. To qualify, we would be required to meet the continued listing requirement for market value of publicly held shares and all other initial listing standards for the Nasdaq Capital Market, with the exception of the bid price requirement, and would need to provide written notice to Nasdaq of our intention to cure the deficiency during the second compliance period, by effecting a reverse stock split, if necessary. However, if it appears to the Nasdaq staff that we will not be able to cure the deficiency, or if we are otherwise not eligible, Nasdaq would notify us that its securities will be subject to delisting.

S-6

TABLE OF CONTENTS

Additionally, on May 1, 2024, we received written notice (the “Delist Notice” and, together with the Bid Notice, the “Notices”) from Nasdaq indicating that, based upon our continued non-compliance with Nasdaq Listing Rule 5550(b)(2) (“Rule 5550(b)(2)”), the Nasdaq staff has determined to delist our common stock from the Nasdaq Capital Market effective May 10, 2024 unless we timely request an appeal of this determination before the Panel by May 8, 2024. We timely requested a hearing before the Panel, which had the effect of staying the suspension of our common stock pending the Panel’s final written decision. During the pendency of our hearing before the Panel, our common stock will remain listed and trading on Nasdaq.

We are diligently working to evidence compliance with all applicable requirements for continued listing on the Nasdaq Capital Market and we expect to submit a plan to that effect to the Panel as part of the hearing process; however, there can be no assurance the Panel will grant any request for continued listing or that we will be able to regain compliance with the applicable listing criteria within the period of time that may be granted by the Panel. The Notices have no immediate effect on the listing or trading of our common stock and the common stock will continue to trade on the Nasdaq Capital Market under the symbol “SEEL.”

We intend to monitor the bid price and market value of our common stock and consider available options if our common stock does not trade at a level likely to result in us regaining compliance with Nasdaq’s minimum bid price rule by October 28, 2024, or the minimum market value of listed securities rule, which may include, among other options, effectuating a reverse stock split. There can be no assurance that we will be able to regain compliance with Nasdaq’s minimum bid price rule or Nasdaq’s minimum market value of listed securities rule or that we will otherwise be in compliance with the other listing standards for the Nasdaq Capital Market.

Recent Developments

Announcement of Strategic Focus on Mental Health and Appointment of Richard Pascoe as Chairman of the Board

On April 29, 2024, we announced our strategic focus on mental health initiatives and that Richard Pascoe has been appointed as the Chairman of the Board of Directors to lead the ongoing strategic process and business development discussions and negotiations. Mr. Pascoe has served as member of our Board of Directors since 2019.

Amendment No. 6 to Convertible Promissory Note

Effective May 1, 2024, we and Lind Global Asset Management V, LLC (“Lind”) entered into an Amendment No. 6 to Convertible Promissory Note (“Amendment No. 6”), which amended the convertible promissory note we previously issued to Lind on November 23, 2021 (as amended, the “Note”). Pursuant to Amendment No. 6, we and Lind agreed, among other things, that: (A) we shall not be required to maintain any minimum balance of cash or cash equivalents with one or more financial institutions prior to May 31, 2024, and that we shall thereafter be required to maintain an aggregate minimum balance equal to 50% of the then outstanding principal amount under the Note or more in cash or cash equivalents with one or more financial institutions; (B) that all payments of accrued interest and monthly payments of the outstanding principal amount payable by us under the Note in shares of common stock shall be reduced from ninety percent (90%) to eighty-five percent (85%) of the average of the five lowest daily volume weighted average price of common stock during the 20 trading days prior to each respective payment date; (C) Lind will, through May 31, 2024, forebear from exercising any right to assert or claim that a Material Adverse Effect (as defined in the Note) has occurred as a result of any event, occurrence, fact, condition or change that occurred on or prior to May 1, 2024.

Reduction in Force

On April 30, 2024, we announced a reduction in its workforce that affected approximately 33% of our current employees (the “RIF”), along with a reduction in working hours and related compensation for all of our remaining employees. This decision relates to our recent announcement of our strategic focus on our mental health initiatives and serves to reduce ongoing operating expenses not related to such initiatives and extend our cash runway. Total annualized cost savings from the RIF are estimated at approximately

S-7

TABLE OF CONTENTS

$0.8 million and total annualized cost savings from the reduction in working hours are estimated at approximately $1.6 million. The RIF was substantially completed on April 30, 2024.

We expect to recognize approximately $50,000 in total charges for related benefits for employees whose employment was terminated pursuant to the RIF. These are one-time termination benefits and are cash charges. The estimates of costs and expenses that we expect to incur in connection with the RIF are subject to a number of assumptions and actual results may differ materially from those estimates. We may also incur other charges or cash expenditures not currently contemplated due to events that may occur as a result of, or associated with, the RIF.

Reverse Stock Split

On May 15, 2024, we filed a Certificate of Change with the Secretary of State of the State of Nevada to (i) effect a 1-for-8 reverse stock split (the “Reverse Stock Split”) of our issued and outstanding shares of common stock, effective at 12:01 a.m. Eastern Time, on May 16, 2024, and (ii) decrease the number of total authorized shares of our common stock from 400,000,000 shares to 50,000,000 shares (the “Authorized Share Decrease”). Our common stock begin trading on a Reverse Stock Split-adjusted basis on the Nasdaq Capital Market at the opening of the market on May 16, 2024.

Except as otherwise indicated, all information in this prospectus supplement gives effect to the Reverse Stock Split and the Authorized Share Decrease.

Corporate Information

Our principal executive offices are located at 300 Park Avenue, 2nd Floor, New York, NY 10022, and our telephone number is (646) 293-2100. Our website is located at www.seelostherapeutics.com. Any information contained on, or that can be accessed through, our website is not incorporated by reference into, nor is it in any way part of, this prospectus supplement and should not be relied upon in connection with making any decision with respect to an investment in our securities. We are required to file annual, quarterly and current reports, proxy statements and other information with the SEC. You may obtain any of the documents filed by us with the SEC at no cost from the SEC’s website at www.sec.gov.

We are a “smaller reporting company” as defined in Rule 12b-2 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and have elected to take advantage of certain of the scaled disclosure available for smaller reporting companies in this prospectus supplement as well as our filings under the Exchange Act.

S-8

TABLE OF CONTENTS

THE OFFERING

Common stock offered by us

380,968 shares.

Pre-Funded Warrants offered by us

Pre-Funded Warrants to purchase up to 81,239 shares of common stock to certain investors whose purchase of shares of common stock in this offering would otherwise result in any such investor, together with such investor’s affiliates and certain related parties, beneficially owning more than 4.99% (or, at the election of an investor, 9.99%) of our outstanding shares of common stock immediately following the consummation of this offering. The purchase price of each Pre-Funded Warrant is equal to the price per share at which the shares of common stock are being sold in this offering, minus $0.001. The exercise price of each Pre-Funded Warrant will equal $0.001 per share. Each Pre-Funded Warrant will be exercisable immediately upon issuance and will not expire prior to exercise. This prospectus supplement and the accompanying prospectus also relate to the offering of the shares of common stock issuable upon exercise of the Pre-Funded Warrants. See “Description of Securities Offered” on page S-25 of this prospectus supplement.

Common stock outstanding before this offering

2,226,776 shares.

Common stock to be outstanding immediately after this offering

2,607,744 shares (assuming no exercise of any Pre-Funded Warrants issued in this offering and no exercise of any Common Warrants issued in the concurrent private placement).

Offering price

$2.46 per share of common stock and $2.459 per Pre-Funded Warrant to purchase one share of common stock.

Use of proceeds

We estimate the net proceeds from this offering and the concurrent private placement will be approximately $0.9 million, after deducting fees payable to the placement agent and other estimated offering expenses payable by us. We intend to use the net proceeds from this offering (excluding proceeds from the exercise of any Common Warrants being offered by us in the concurrent private placement) to initially repay approximately $0.26 million of principal and accrued interest under the outstanding convertible promissory note in an initial aggregate principal amount of $22.0 million (the “Note”) that we previously issued and sold to Lind Global Asset Management V, LLC (“Lind”) as required under the Note and the remainder for general corporate purposes and to advance the development of our product candidates. We may also use the net proceeds from this offering to make periodic principal and interest payments under, or to repay a portion of, the Note. See “Use of Proceeds” beginning on page S-21 of this prospectus supplement for additional detail.

Concurrent private placement

In a concurrent private placement, we are selling to purchasers of our common stock in this offering, for no additional consideration, a Common Warrant to purchase two shares of common stock for each share of common stock purchased in this offering and for each share of common stock issuable upon exercise of Pre-Funded Warrants purchased in this offering. The Common Warrants will be exercisable upon issuance at an

S-9

TABLE OF CONTENTS

exercise price of $2.21 per share and will expire on the date that is 5 years following the original issuance date. The Common Warrants and the shares of our common stock issuable upon the exercise of the Common Warrants are not being registered under the Securities Act pursuant to the registration statement of which this prospectus supplement and the accompanying base prospectus form a part and are not being offered pursuant to this prospectus supplement and the accompanying base prospectus. The Common Warrants are being offered pursuant to an exemption from the registration requirements of the Securities Act provided in Section 4(a)(2) of the Securities Act and/or Rule 506(b) of Regulation D thereunder. See “Private Placement Transaction and Common Warrants” on page S-27 of this prospectus supplement.

Trading symbol

Our common stock is listed on the Nasdaq Capital Market under the symbol “SEEL.” There is no established public trading market for the Pre-Funded Warrants and we do not expect a market to develop. We do not intend to apply to list the Pre-Funded Warrants on any national securities exchange or other nationally recognized trading system. Without an active market, the liquidity of the Pre-Funded Warrants will be limited.

Risk factors

Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page S-12 of this prospectus supplement and other information included or incorporated by reference into this prospectus supplement for a discussion of factors you should carefully consider before investing in our securities.

Participation right

Pursuant to the terms of the Note, Lind has the right to purchase an amount equal to the lesser of (i) fifty percent (50%), and (ii) $5,000,000 of the securities being offered in this offering and the concurrent private placement.

Lock-up agreements

We and our executive officers and directors have agreed, that, subject to certain exceptions, we and our directors and officers will not, until 45 days after the closing of this offering, offer, sell, contract to sell, hypothecate, pledge or otherwise dispose of any shares of our common stock.

Our authorized capital stock consists of 50,000,000 shares of our common stock and 10,000,000 shares of our preferred stock, $0.001 par value per share. The number of shares of our common stock outstanding before this offering and to be outstanding immediately after this offering is based on 1,907,081 shares of our common stock issued and outstanding as of March 31, 2024, after giving effect to the Reverse Stock Split and the Authorized Share Decrease and the issuance of an aggregate of 319,695 shares of our common stock issued to the holder of the Note to satisfy principal and interest payments thereunder between April 1, 2024 and May 15, 2024.

The number of shares of our common stock outstanding before this offering and that will be outstanding immediately after this offering excludes: (a) the shares of common stock issuable upon exercise of the Pre-Funded Warrants being offered by us in this offering, (b) the shares of common stock issuable upon exercise of the Common Warrants being offered by us in the concurrent private placement, and (c) the following:

•

97,362 shares of our common stock issuable upon the exercise of stock options outstanding under the 2012 Plan as of March 31, 2024, at a weighted-average exercise price of $252.00 per share;

S-10

TABLE OF CONTENTS

•

65 shares of our common stock issuable upon the exercise of stock options outstanding under the 2016 Plan issued on September 23, 2016 and outstanding as of March 31, 204, at a weighted-average exercise price of $156.00 per share;

•

1,371 shares of our common stock issuable upon the exercise of stock options outstanding under the 2019 Inducement Plan as of March 31, 2024, at a weighted-average exercise price of $336.37 per share;

•

1,083,437 shares of our common stock issuable upon the exercise of outstanding warrants as of March 31, 2024, at a weighted-average exercise price of $28,52 per share;

•

613 shares of our common stock reserved for future issuance under our Amended and Restated 2012 Stock Long Term Incentive Plan (the “2012 Plan”) as of March 31, 2024;

•

2,770 shares of our common stock reserved for future issuance under our 2019 Inducement Plan (the “2019 Inducement Plan”) as of March 31, 2024;

•

13,429 shares of our common stock reserved for future issuance under our 2020 Employee Stock Purchase Plan (the “ESPP”) as of March 31, 2024; and

•

up to 8,964 shares of our common stock issuable upon conversion of the Note in an aggregate principal amount of $12.9 million as of March 31, 2024, which is convertible by the holder thereof at a price of $1,440.00 per share.

Except as otherwise indicated, all information in this prospectus supplement gives effect to the 1-for-8 reverse stock split of our common stock that was effected on May 16, 2024 and the associated decrease in our authorized shares of common stock from 400,000,000 shares to 50,000,000 shares and assumes no exercise of the Pre-Funded Warrants or the Common Warrants being issued in the concurrent private placement.

S-11

TABLE OF CONTENTS

RISK FACTORS

Our Annual Report on Form 10-K for the year ended December 31, 2023 and our Quarterly Report on Form 10-Q for the quarter ended March 31, 2024, which are incorporated by reference into this prospectus supplement, as well as our other filings with the SEC, includes material risk factors relating to our business. Those risks and uncertainties and the risks and uncertainties described below are not the only risks and uncertainties that we face. Additional risks and uncertainties that are not presently known to us or that we currently deem immaterial or that are not specific to us, such as general economic conditions, may also materially and adversely affect our business and operations. If any of those risks and uncertainties or the risks and uncertainties described below actually occurs, our business, financial condition or results of operations could be harmed substantially. In such a case, you may lose all or part of your investment. You should carefully consider the risks and uncertainties described below and those risks and uncertainties incorporated by reference into this prospectus supplement, as well as the other information included in this prospectus supplement, before making an investment decision with respect to our common stock.

Risks Related to this Offering

Purchasers of securities will experience immediate and substantial dilution in the book value of their investment. You may experience further dilution upon exercise of our outstanding options and warrants.

If you purchase shares of our common stock in this offering, you will experience immediate and substantial dilution, as the offering price of our common stock will be substantially greater than the as adjusted net tangible book value per share of our common stock before giving effect to this offering. Accordingly, if you purchase the securities in this offering, you will incur immediate substantial dilution of approximately $14.66 per share, representing the difference between the offering price per share of our common stock and our as adjusted net tangible book value as of March 31, 2024. In addition, if the holders of the Pre-Funded Warrants or the Common Warrants exercise such warrants, or if outstanding options or warrants to purchase our common stock are exercised, you will experience further dilution. For a further description of the dilution that you will experience immediately after this offering, see the section titled “Dilution” beginning on page S-23 of this prospectus supplement.

Future sales of our common stock, or the perception that such future sales may occur, may cause our stock price to decline.

Sales of a substantial number of shares of our common stock in the public market, or the perception that these sales could occur, following this offering could cause the market price of our common stock to decline. A substantial majority of the outstanding shares of our common stock are, and the shares of common stock, including shares issuable upon exercise of any Pre-Funded Warrants, sold in this offering upon issuance will be, freely tradable without restriction or further registration under the Securities Act of 1933, as amended.

There is no public market for the Pre-Funded Warrants being offered in this offering.

There is no established public trading market for the Pre-Funded Warrants to purchase shares of our common stock being offered in this offering, and we do not expect a market to develop. In addition, we do not intend to apply to list the Pre-Funded Warrants on any national securities exchange or other nationally recognized trading system. Without an active market, the liquidity of the Pre-Funded Warrants will be limited.

Holders of the Pre-Funded Warrants will have no rights as a common stockholder until such holders exercise their Pre-Funded Warrants and acquire our common stock.

Until holders of Pre-Funded Warrants acquire shares of our common stock upon exercise of such warrants, holders of the Pre-Funded Warrants will have no rights with respect to the shares of our common stock underlying the Pre-Funded Warrants. Upon exercise of the Pre-Funded Warrants, the holders will be entitled to exercise the rights of a common stockholder only as to matters for which the record date occurs after the exercise date.

S-12

TABLE OF CONTENTS

We have broad discretion to determine how to use the funds raised in this offering, and may use them in ways that may not enhance our operating results or the price of our common stock.

Our management will have broad discretion over the use of proceeds from this offering, and we could spend the proceeds from this offering in ways our stockholders may not agree with or that do not yield a favorable return, if at all. We intend to use the net proceeds from this offering to initially repay $0.26 million of principal and accrued interest under the Note and the remainder for general corporate purposes and to advance the development of our product candidates. We will also use the net proceeds from this offering to make additional periodic principal and interest payments under the Note. See “Use of Proceeds” beginning on page S-21 of this prospectus supplement for additional detail. However, our use of these proceeds may differ substantially from our current plans. If we do not invest or apply the proceeds from this offering in ways that improve our operating results, we may fail to achieve expected financial results, which could cause our stock price to decline.

We do not expect to pay dividends in the foreseeable future. As a result, you must rely on stock appreciation for any return on your investment.

We have never declared or paid cash dividends on our common stock and do not anticipate paying cash dividends on our common stock in the foreseeable future. Any payment of cash dividends will also depend on our financial condition, results of operations, capital requirements and other factors and will be at the discretion of our board of directors, subject to limitations under applicable law. Accordingly, you will have to rely on capital appreciation, if any, to earn a return on your investment in our common stock.

Risks Related to the Company

Our debt agreement contains restrictive and financial covenants that may limit our operating flexibility and the failure to comply with such covenants could cause our outstanding debt to become immediately payable.

On November 23, 2021, we issued and sold the Note to Lind. The Note, as amended, contains certain restrictive covenants and event of default provisions, including restrictions on certain sales or other dispositions of company assets, restrictions on entering into certain variable-rate transactions and a covenant requiring us to maintain an aggregate minimum balance equal to 50% of the then outstanding principal amount under the Note or more in cash and cash equivalents commencing on May 31, 2024. As of May 16, 2024, the outstanding principal amount of the Note was approximately $12.5 million and our cash and cash equivalents as of March 31, 2024 were approximately $0.5 million. Based on our current operating plan and our cash balance as of March 31, 2024, and even after giving effect to the receipt of proceeds from this offering, we do not expect to be able to maintain the minimum cash balance required to satisfy this covenant if we do not raise additional financing by May 31, 2024. In the event we fail to meet the minimum cash balance as required under the Note, and if we are unable to cure such default within fifteen business days from its occurrence or otherwise obtain a waiver from Lind or amend the terms of the Note, we would trigger a default under the Note. If we are not able to comply or regain compliance with any of the covenants in, or otherwise fail to make cash payments or trigger a default under, the Note, Lind could declare the Note immediately due and payable, which would require us to pay 120% of the outstanding principal amount of the Note and would have a material adverse effect on our liquidity, financial condition, operating results, business and prospects, and could cause the price of our common stock to decline. In addition, since the borrowings under the Note are secured by a first priority lien on our assets, Lind would be able to foreclose on our assets if we do not cure any default or pay any amounts due and payable under the Note. In addition, upon an Event of Default (as defined in the Note), Lind shall have the right to convert the then outstanding principal amount of the Note into shares of our common stock at the lower of (x) the then-current conversion price (which is currently $1,440.00 per share, subject to adjustment in certain circumstances as described in the Note) and (y) 85% of the average of the five lowest daily volume weighted average price of our common stock during the 20 trading days prior to the delivery by Lind of a notice of conversion.

S-13

TABLE OF CONTENTS

Risks Related to Owning Our Common Stock

If we fail to comply with the continued listing requirements of the Nasdaq Capital Market, our common stock may be delisted and the price of our common stock and our ability to access the capital markets could be negatively impacted.

We must continue to satisfy the Nasdaq Capital Market’s continued listing requirements, including, among other things, a minimum closing bid price requirement of $1.00 per share for 30 consecutive business days. If a company fails for 30 consecutive business days to meet the $1.00 minimum closing bid price requirement, The Nasdaq Stock Market LLC (“Nasdaq”) will send a deficiency notice to the company, advising that it has been afforded a “compliance period” of 180 calendar days to regain compliance with the applicable requirements.

A delisting of our common stock from the Nasdaq Capital Market could materially reduce the liquidity of our common stock and result in a corresponding material reduction in the price of our common stock. In addition, delisting could harm our ability to raise capital through alternative financing sources on terms acceptable to us, or at all, and may result in the potential loss of confidence by investors and employees.

On April 30, 2024, we received a written notice (the “Bid Notice”) from The Nasdaq Stock Market LLC (“Nasdaq”) indicating that, for the last thirty consecutive business days, the bid price for our common stock had closed below the minimum $1.00 per share requirement for continued listing on the Nasdaq Capital Market under Nasdaq Listing Rule 5550(a)(2) (“Rule 5550(a)(2)”). In accordance with Nasdaq Listing Rule 5810(c)(3)(A), we have been provided an initial period of 180 calendar days, or until October 28, 2024, to regain compliance. The Bid Notice states that the Nasdaq staff will provide written confirmation that the Company has achieved compliance with Rule 5550(a)(2) if at any time before October 28, 2024, the bid price of the Company’s common stock closes at $1.00 per share or more for a minimum of ten consecutive business days.

On November 2, 2023, we received a written notice (the “Initial Notice”) from Nasdaq indicating that, for the last thirty-two consecutive business days, the market value of our listed securities has been below the minimum requirement of $35 million for continued listing on the Nasdaq Capital Market under Nasdaq Listing Rule 5550(b)(2) (“Rule 5550(b)(2)”). In accordance with Nasdaq Listing Rule 5810(c)(3)(C), we were provided a period of 180 calendar days, or until April 30, 2024, to regain compliance. The Initial Notice stated that the Nasdaq staff will provide written notification that we have achieved compliance with Rule 5550(b)(2) if at any time before April 30, 2024, the market value of our common stock closes at $35 million or more for a minimum of ten consecutive business days.

On May 1, 2024, we received written notice (the “Delist Notice” and, together with the Bid Notice and Initial Notice, the “Notices”) from Nasdaq indicating that, based upon our continued non-compliance with Rule 5550(b)(2), the Nasdaq staff has determined to delist our common stock from the Nasdaq Capital market effective May 10, 2024 unless we timely request an appeal of this determination before the Nasdaq Hearings Panel (the “Panel”) by May 8, 2024. We timely requested a hearing before the Panel, which had the effect of staying the suspension of the Company’s common stock pending the Panel’s final written decision. During the pendency of our hearing before the Panel, our common stock will remain listed and trading on Nasdaq.

On May 15, 2024, we filed a Certificate of Change (the “Certificate of Change”) with the Secretary of State of the State of Nevada to (i) effect a 1-for-8 reverse stock split (the “Reverse Stock Split”) of our issued and outstanding shares of common stock, effective at 12:01 a.m. Eastern Time, on May 16, 2024, and (ii) decrease the number of total authorized shares of our common stock from 400,000,000 shares to

S-14

TABLE OF CONTENTS

50,000,000 shares. The Reverse Stock Split was intended, among other reasons, to allow us to achieve the requisite increase in the market price of our common stock to be in compliance with the minimum bid price of Nasdaq. However, there can be no assurance that the price of our common stock will stay above the minimum requirements for the time period required by Nasdaq in order to regain compliance with the rule.

In addition, we have previously received similar notices from Nasdaq that our bid price of our common stock had closed below the minimum $1.00 per share requirement for continued listing on the Nasdaq Capital Market under Rule 5550(a)(2), and that the market value of our listed securities has been below the minimum requirements of $35 million for continued listing on the Nasdaq Capital Market under Rule 5550(b)(2). Even though we previously regained compliance with the Nasdaq Capital Market’s minimum closing bid price requirement, and minimum market value of listed securities requirement, there is no guarantee that we will remain in compliance with such listing requirements or other listing requirements in the future. Any failure to maintain compliance with continued listing requirements of the Nasdaq Capital Market could result in delisting of our common stock from the Nasdaq Capital Market and negatively impact our company and holders of our common stock, including by reducing the willingness of investors to hold our common stock because of the resulting decreased price, liquidity and trading of our common stock, limited availability of price quotations and reduced news and analyst coverage. Delisting may adversely impact the perception of our financial condition, cause reputational harm with investors, our employees and parties conducting business with us and limit our access to debt and equity financing.

We cannot predict the effect that the Reverse Stock Split will have on the market price for shares of our common stock.

We cannot predict the effect of the Reverse Stock Split upon the market price for our common stock, and the history of similar reverse stock splits for companies in like circumstances has varied. Some investors may have a negative view of a reverse stock split. Even if the Reverse Stock Split has a positive effect on the market price for shares of our common stock, performance of our business and financial results, general economic conditions and the market perception of our business, and other adverse factors which may not be in our control could lead to a decrease in the price of our common stock following the Reverse Stock Split.

Even if the Reverse Stock Split does result in an increased market price per share of our common stock, the market price per share following the Reverse Stock Split may not increase in proportion to the reduction of the number of shares of our common stock outstanding before the implementation of the Reverse Stock Split. Accordingly, even with an increased market price per share, the total market capitalization of shares of our common stock after the Reverse Stock Split could be lower than the total market capitalization before the Reverse Stock Split. Also, even if there is an initial increase in the market price per share of our common stock after the Reverse Stock Split, the market price many not remain at that level.

If the market price of our common stock declines following the Reverse Stock Split, the percentage decline as an absolute number and as a percentage of our overall market capitalization may be greater than would occur in the absence of the Reverse Stock Split due to decreased liquidity in the market for our common stock. Accordingly, the total market capitalization of our common stock following the Reverse Stock Split could be lower than the total market capitalization before the Reverse Stock Split.

S-15

TABLE OF CONTENTS

DISCLOSURE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement and the accompanying prospectus and the documents incorporated by reference into this prospectus supplement and the accompanying prospectus may contain “forward-looking statements” by us within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Exchange Act, including, without limitation, statements as to expectations, beliefs and strategies regarding the future. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. These forward-looking statements rely on a number of assumptions concerning future events and include statements relating to:

•

the potential impact to our business, financial condition and employees, including disruptions to our clinical trials, preclinical studies, supply chain and operations;

•

risks and uncertainties associated with our actual and proposed research and development activities, including our clinical trials and preclinical studies;

•

the timing or likelihood of regulatory filings and approvals or of alternative regulatory pathways for our product candidates;

•

the potential market opportunities for commercializing our product candidates;

•

our expectations regarding the potential market size and the size of the patient populations for our product candidates, if approved for commercial use, and our ability to serve such markets;

•

estimates of our expenses, future revenue, capital requirements and our needs for additional financing;

•

our ability to continue as a going concern;

•

our ability to maintain the listing of our common stock on the Nasdaq Capital Market;

•

our ability to develop, acquire and advance our product candidates into, and successfully complete, clinical trials and preclinical studies and obtain regulatory approvals;

•

the implementation of our business model and strategic plans for our business and product candidates;

•

the initiation, cost, timing, progress and results of future and current preclinical studies and clinical trials, and our research and development programs;

•

the terms of future licensing arrangements, and whether we can enter into such arrangements at all;

•

timing and receipt or payments of licensing and milestone revenues or payments, if any;

•

the scope of protection we are able to establish and maintain for intellectual property rights covering our product candidates and our ability to operate our business without infringing the intellectual property rights of others;

•

regulatory developments in the United States and foreign countries;

•

the performance of our third-party suppliers and manufacturers;

•

our ability to maintain and establish collaborations or obtain additional funding;

•

the success of competing therapies that are currently or may become available;

•

our use of proceeds from this offering;

•

our financial performance; and

•

developments and projections relating to our competitors and our industry.

Any forward-looking statements should be considered in light of these factors. Words such as “anticipates,” “believes,” “forecasts,” “potential,” “goal,” “contemplates,” “expects,” “intends,” “plans,” “projects,” “hopes,” “seeks,” “estimates,” “strategy,” “continues,” “ongoing,” “opportunity,” “could,” “would,” “should,” “likely,” “will,” “may,” “can,” “designed to,” “future,” “foreseeable future” and similar expressions and variations, and negatives of these words, identify forward-looking statements. These forward-looking

S-16

TABLE OF CONTENTS

statements are based on the expectations, estimates, projections, beliefs and assumptions of our management based on information currently available to management, all of which are subject to change. These forward-looking statements are not guarantees of future performance and are subject to risks and uncertainties that could cause actual results to differ materially from the results contemplated by the forward-looking statements. Many of the important factors that will determine these results and values are beyond our ability to control or predict. You are cautioned not to put undue reliance on any forward-looking statements. Except as otherwise required by law, we do not assume any obligation to update any forward-looking statements.

In evaluating an investment in shares of our securities, you should carefully consider the discussion of risks and uncertainties described under the heading “Risk Factors” contained in this prospectus supplement, and under similar headings in other documents, including in our Annual Report on Form 10-K for the fiscal year ended December 31, 2023, our Quarterly Report on Form 10-Q for the quarter ended March 31, 2024 and in our other filings with the SEC, that are incorporated by reference in this prospectus supplement. You should carefully read this prospectus supplement together with the information incorporated by reference in this prospectus supplement as described under the headings “Where You Can Find More Information” and “Information Incorporated by Reference” completely and with the understanding that our actual future results may be materially different from what we expect.

All subsequent written and oral forward-looking statements attributable to us or persons acting on our behalf are expressly qualified in their entirety by our cautionary statements. The forward-looking statements included or incorporated by reference herein are made only as of the date of this prospectus supplement (or as of the date of any such document incorporated by reference). We do not intend, and undertake no obligation, to update these forward-looking statements, except as required by law.

S-17

TABLE OF CONTENTS

MARKET AND INDUSTRY DATA

Unless otherwise indicated, we have based the information concerning our industry contained in this prospectus supplement and incorporated by reference herein on our general knowledge of and expectations concerning the industry, which involve risks and uncertainties and are subject to change based on various factors, including those discussed in the “Risk Factors” section of this prospectus supplement and in the other information contained or incorporated by reference in this prospectus supplement. These and other factors could cause the information concerning our industry to differ materially from those expressed in this prospectus supplement and incorporated by reference herein.

S-18

TABLE OF CONTENTS

SELECTED FINANCIAL DATA

Reverse Stock Split

On May 16, 2024, we effected a 1-for-8 reverse stock split of our common stock. In connection with the reverse stock split, the total number of authorized shares of our common stock was decreased from 400,000,000 shares to 50,000,000 shares. Our audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2023 that are incorporated by reference into this prospectus are presented without giving effect to the Reverse Stock Split. Except where the context otherwise requires, share numbers in this prospectus reflect the 1-for-8 reverse stock split of our common stock.

The following selected financial data has been derived from our audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2023 and our unaudited condensed consolidated interim financial statements for the quarter ended March 31, 2024 included in our Quarterly Report on Form 10-Q for the quarter ended March 31, 2024, as adjusted to reflect the Reverse Stock Split for all periods presented. Our historical results are not indicative of the results that may be expected in the future and results of interim periods are not indicative of the results for the entire year.

AS REPORTED (in thousands, except per share data)

	Year Ended December 31,
	2023			2022
Net loss and comprehensive loss		$	(37,882)		$	(73,534)
Total loss per share basic		$	(7.73)		$	(20.74)
Total loss per share-diluted		$	(7.73)		$	(20.74)
Weighted-average common shares outstanding used for basic			4,900,222			3,545,691
Weighted-average common shares outstanding used for diluted			4,900,222			3,545,691
Common stock outstanding at period end			9,794,594			3,572,417

	Three Months Ended March 31,
	2024			2023
Net loss and comprehensive loss		$	(2,664)		$	(13,431)
Total loss per share basic		$	(0.20)		$	(3.58)
Total loss per share-diluted		$	(0.20)		$	(3.58)
Weighted-average common shares outstanding used for basic			13,007,556			3,751,468
Weighted-average common shares outstanding used for diluted			13,007,556			3,751,468
Common stock outstanding at period end			15,256,268			4,060,370

AS ADJUSTED FOR 1-FOR-8 REVERSE STOCK SPLIT (in thousands, except per share data):

	Year Ended December 31,
	2023			2022
Net loss and comprehensive loss		$	(37,882)		$	(73,534)
Total loss per share basic		$	(61.84)		$	(165.90)
Total loss per share-diluted		$	(61.84)		$	(165.90)
Weighted-average common shares outstanding used for basic			612,569			443,245
Weighted-average common shares outstanding used for diluted			612,569			443,245
Common stock outstanding at period end			1,224,371			446,576

S-19

TABLE OF CONTENTS

	Three Months Ended March 31,
	2024			2023
Net loss and comprehensive loss		$	(2,664)		$	(13,431)
Total loss per share basic		$	(1.64)		$	(28.64)
Total loss per share-diluted		$	(1.64)		$	(28.64)
Weighted-average common shares outstanding used for basic			1,625,991			468,971
Weighted-average common shares outstanding used for diluted			1,625,991			468,971
Common stock outstanding at period end			1,907,081			546,511

S-20

TABLE OF CONTENTS

USE OF PROCEEDS

We estimate that the net proceeds from the sale of the common stock and the Pre-Funded Warrants in this offering and the sale of the Common Warrants in the concurrent private placement will be approximately $0.9 million, after deducting fees payable to the placement agent and estimated offering expenses payable by us.

We intend to use the net proceeds from this offering to initially repay $0.26 million of principal and accrued interest under the Note and the remainder for general corporate purposes and to advance the development of our product candidates. We will also use the net proceeds from this offering to make periodic principal and interest payments under, or to repay a portion of, the Note. We are required to utilize 25% of the net cash proceeds of this offering to repay the Note unless Lind notifies us that it has elected not to be repaid. The Note had an initial principal amount of $22,000,000, was issued on November 23, 2021 and commenced bearing interest at 5% per annum on November 23, 2022. As of May 16, 2024, the principal amount of the Note was approximately $12.5 million. Beginning on November 23, 2022, the Note began amortizing in twenty-four monthly installments equal to the quotient of (i) the then-outstanding principal amount of the Note, divided by (ii) the number of months remaining until the November 23, 2024 maturity date of the Note. All amortization payments under the Note are payable, at our sole option, in cash, shares of our common stock or a combination of both. In addition, on the last business day of each month following November 23, 2022, we must pay, on a monthly basis, all interest that has accrued and remains unpaid on the then-outstanding principal amount of the Note. If we elect to make any amortization payments in cash, we must pay a 5% premium on each cash payment.

The precise amount and timing of the application of these proceeds will depend upon a number of factors, such as the timing and progress of our research and development efforts, our funding requirements and the availability and costs of other funds. As of the date of this prospectus supplement, we cannot specify with certainty all of the particular uses for the net proceeds to us from this offering. Depending on the outcome of our efforts and other unforeseen events, our plans and priorities may change and we may apply the net proceeds of this offering in different manners than we currently anticipate. Accordingly, our management will have broad discretion in the timing and application of these proceeds. Pending application of the net proceeds as described above, we intend to temporarily invest the proceeds in short-term, interest-bearing investment grade instruments, certificates of deposit or direct or guaranteed obligations of the U.S. government.

S-21

TABLE OF CONTENTS

DIVIDEND POLICY

We have never declared or paid cash dividends on our common stock and do not anticipate paying cash dividends on our common stock in the foreseeable future. The payment of dividends on our capital stock will depend on our earnings, financial condition and other business and economic factors affecting us at such time as the board of directors may consider relevant. If we do not pay dividends, our common stock may be less valuable because a return on your investment will only occur if the common stock price appreciates.

S-22

TABLE OF CONTENTS

DILUTION

Purchasers of securities in this offering will experience immediate dilution to the extent of the difference between the offering price per share of common stock and Pre-Funded Warrants paid by the purchasers and the pro forma as adjusted net tangible book value per share of common stock immediately after this offering and the concurrent private placement (excluding the shares of common stock issuable upon exercise of the Pre-Funded Warrants being offered in this offering and the shares of common stock issuable upon exercise of the Common Warrants being issued in the concurrent private placement and the payment of the exercise price therefor).

Our net tangible book value as of March 31, 2024 was approximately $(33.1) million, or $(17.36) per share of common stock. Net tangible book value per share is determined by dividing the net of total tangible assets less total liabilities, by the aggregate number of shares of common stock outstanding as of March 31, 2024.

Our pro forma net tangible book value as of March 31, 2024 was approximately $(32.7) million, or $(14.70) per share of common stock. Pro forma net tangible book value per share is determined by dividing the net of total tangible assets less total liabilities, by the aggregate number of shares of common stock outstanding as of March 31, 2024, after giving effect to the issuance of an aggregate of 319,695 shares of our common stock issued to the holder of the Note to satisfy principal and interest payments thereunder between April 1, 2024 and May 15, 2024.

After giving effect to: (i) the pro forma adjustments described in the preceding paragraph and (ii) the sale by us of 380,968 shares of common stock (excluding shares of common stock issuable upon exercise of the Pre-Funded Warrants and shares of common stock issuable upon exercise of the Common Warrants being issued in the concurrent private placement), and after deducting fees payable to the placement agent and estimated offering expenses, our pro forma as adjusted net tangible book value as of March 31, 2024 would have been approximately $(31.8) million, or $(12.20) per share of common stock. This represents an immediate increase in the pro forma net tangible book value of $2.50 per share to our existing stockholders and an immediate dilution in pro forma net tangible book value of $14.66 per share of common stock issued to the investors participating in this offering.

If holders of Pre-Funded Warrants and Common Warrants being issued in the concurrent private placement exercise the Pre-Funded Warrants and Common Warrants in full, the pro forma as adjusted net tangible book value per share of common stock after giving effect to this offering would be $(29.80) per share, and the dilution in net tangible book value per share to investors purchasing common stock in this offering would be $10.22 per share.

The following table illustrates this per share dilution:

Offering price per share of common stock			$	2.46
Net tangible book value per share as of March 31, 2024	$	(17.36)
Increase in net tangible book value per share attributable to the issuance of an aggregate of 319,695 shares of our common stock issued to the holder of the Note to satisfy principal and interest payments thereunder between April 1, 2024 and May 15, 2024	$	2.66
Pro forma net tangible book value per share as of March 31, 2024	$	(14.70)
Increase in net tangible book value per share attributable to this offering	$	2.50
Pro forma as adjusted net tangible book value per share as of March 31, 2024, after giving effect to this offering			$	(12.20)
Dilution per share to investors participating in this offering			$	14.66

The above discussion and table are based on 1,907,081 shares of our common stock issued and outstanding as of March 31, 2024, after giving effect to the Reverse Stock Split and the Authorized Share Decrease and the issuance of an aggregate of 319,695 shares of our common stock issued to the holder of the Note to satisfy principal and interest payments thereunder between April 1, 2024 and May 15, 2024.

S-23

TABLE OF CONTENTS

•

97,362 shares of our common stock issuable upon the exercise of stock options outstanding under the 2012 Plan as of March 31, 2024, at a weighted-average exercise price of $252.00 per share;

•

65 shares of our common stock issuable upon the exercise of stock options outstanding under the 2016 Plan issued on September 23, 2016 and outstanding as of March 31, 2024, at a weighted-average exercise price of $156.00 per share;

•

1,083,437 shares of our common stock issuable upon the exercise of outstanding warrants as of March 31, 2024, at a weighted-average exercise price of $28.52 per share;

•

613 shares of our common stock reserved for future issuance under the 2012 Plan as of March 31, 2024;

•

2,770 shares of our common stock reserved for future issuance under the 2019 Inducement Plan as of March 31, 2024;

•

13,429 shares of our common stock reserved for future issuance under the ESPP as of March 31, 2024; and

•

To the extent that options or warrants, including any of the Pre-Funded Warrants being offered by us in this offering or any of the Common Warrants being issued in the concurrent private placement, are exercised, new options or other equity awards are issued under our equity incentive plans, or we issue additional shares of common stock or other equity or convertible debt securities in the future, there may be further dilution to investors participating in this offering. Moreover, we may choose to raise additional capital because of market conditions or strategic considerations, even if we believe that we have sufficient funds for our current or future operating plans. If we raise additional capital through the sale of equity or convertible debt securities, the issuance of these securities could result in further dilution to our stockholders.

S-24

TABLE OF CONTENTS

DESCRIPTION OF SECURITIES OFFERED

We are offering 380,968 shares of our common stock and Pre-Funded Warrants to purchase up to 81,239 shares of our common stock. We are also registering the shares of common stock issuable from time to time upon exercise of the Pre-Funded Warrants offered hereby.

Common Stock

The material terms and provisions of our common stock and each other class of our securities which qualifies or limits our common stock are described in the section entitled “Description of Capital Stock” beginning on page 46 of the accompanying prospectus and the “Description of Securities” included as Exhibit 4.6 to our Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on March 6, 2024.

Pre-Funded Warrants

The following summary of certain terms and provisions of the Pre-Funded Warrants that are being offered hereby is not complete and is subject to, and qualified in its entirety by, the provisions of the Pre-Funded Warrant, the form of which will be filed as an exhibit to a Current Report on Form 8-K in connection with this offering and incorporated by reference into the registration statement of which this prospectus supplement forms a part. Prospective investors should carefully review the terms and provisions of the form of Pre-Funded Warrant for a complete description of the terms and conditions of the Pre-Funded Warrants.

Pre-Funded Warrants will be issued in certificated form only.

Duration and exercise price

Each Pre-Funded Warrant offered hereby has an initial exercise price per share equal to $0.001. The Pre-Funded Warrants will be immediately exercisable and have an indefinite term. The exercise price and number of shares of common stock issuable upon exercise is subject to appropriate adjustment in the event of stock dividends, stock splits, reorganizations or similar events affecting our common stock and the exercise price.

Exercisability

The Pre-Funded Warrants will be exercisable, at the option of each holder, in whole or in part, by delivering to us a duly executed exercise notice accompanied by payment in full for the number of shares of our common stock purchased upon such exercise (except in the case of a cashless exercise as discussed below). A holder (together with its affiliates) may not exercise any portion of such holder’s Pre-Funded Warrant to the extent that the holder would own more than 9.99% (or, at the election of the purchaser, 4.99%) of the outstanding shares of common stock immediately after exercise, except that upon prior notice from the holder to us, the holder may increase the amount of ownership of outstanding shares of common stock after exercising the holder’s Pre-Funded Warrants up to 9.99% of the number of shares of common stock outstanding immediately after giving effect to the exercise, as such percentage ownership is determined in accordance with the terms of the Pre-Funded Warrants. No fractional shares of common stock will be issued in connection with the exercise of a Pre-Funded Warrant. In lieu of fractional shares, we will either pay the holder an amount in cash equal to the fractional amount multiplied by the exercise price or round up to the next whole share.

Cashless exercise

The Pre-Funded Warrants may be exercised, in whole or in part, by means of cashless exercise. In lieu of making the cash payment otherwise contemplated to be made to us upon such exercise in payment of the aggregate exercise price, the holder may elect instead to receive upon such exercise (either in whole or in part) the net number of shares of common stock determined according to a formula set forth in the Pre-Funded Warrants.

S-25

TABLE OF CONTENTS

Fundamental transactions

In the event of any fundamental transaction, as described in the Pre-Funded Warrants and generally including any merger with or into another entity, sale of all or substantially all of our assets, tender offer or exchange offer, or reclassification of our shares of common stock, upon any subsequent exercise of a Pre-Funded Warrant, the holder will have the right to receive as alternative consideration, for each share of common stock that would have been issuable upon such exercise immediately prior to the occurrence of such fundamental transaction, the number of shares of common stock of the successor or acquiring corporation of our company, if it is the surviving corporation, and any additional consideration receivable upon or as a result of such transaction by a holder of the number of shares of common stock for which the Pre-Funded Warrant is exercisable immediately prior to such event. Additionally, as more fully described in the Common Warrants, in the event of certain fundamental transactions, the holders of the Common Warrants will be entitled to receive consideration in an amount equal to the Black Scholes value of the Common Warrants on the date of consummation of the transaction.

Transferability

Subject to applicable laws, a Pre-Funded Warrant or the rights thereunder may be transferred or assigned, in whole or in part. The ownership of the Pre-Funded Warrants and any transfers of the Pre-Funded Warrants will be registered in a warrant register maintained by the warrant agent. We will initially act as warrant agent.

Exchange listing

There is no trading market available for the Pre-Funded Warrants on any securities exchange or nationally recognized trading system. We do not intend to list the Pre-Funded Warrants on any securities exchange or nationally recognized trading system.

Right as a stockholder

Except as otherwise provided in the Pre-Funded Warrants or by virtue of such holder’s ownership of shares of our common stock, the holders of the Pre-Funded Warrants do not have the rights or privileges of holders of our common stock, including any voting rights, until they exercise their Pre-Funded Warrants.

S-26

TABLE OF CONTENTS

PRIVATE PLACEMENT TRANSACTION AND COMMON WARRANTS

In a concurrent private placement, we are selling to each of the investors in this offering, for no additional consideration, Common Warrants to purchase two shares of common stock for each share purchased in this offering and for each share of common stock issuable upon exercise of Pre-Funded Warrants purchased in this offering.

The Common Warrants and the shares of common stock issuable upon the exercise of the Common Warrants are not being registered under the Securities Act, are not being offered pursuant to this prospectus supplement and the accompanying prospectus and are being offered pursuant to the exemption provided in Section 4(a)(2) of the Securities Act and/or Rule 506(b) of Regulation D thereunder. Accordingly, the purchaser may only sell the shares of common stock issued upon exercise of the Common Warrants pursuant to an effective registration statement under the Securities Act covering the resale of those shares, an exemption under Rule 144 under the Securities Act or another applicable exemption under the Securities Act.

The following summary of certain terms and provisions of the Common Warrants is not complete and is subject to, and qualified in its entirety by, the provisions of the Common Warrant, the form of which will be filed as an exhibit to a Current Report on Form 8-K in connection with this offering and incorporated by reference into the registration statement of which this prospectus supplement forms a part.

Common Warrants will be issued in certificated form only.

Duration and exercise price

Each Common Warrant offered hereby has an initial exercise price per share equal to $2.21. The Common Warrants are exercisable effective immediately and will expire on the date that is five years following the original issuance date. The exercise price and number of shares of common stock issuable upon exercise is subject to appropriate adjustment in the event of stock dividends, stock splits, reorganizations or similar events affecting our common stock and the exercise price.

Exercisability

The Common Warrants will be exercisable, at the option of each holder, in whole or in part, by delivering to us a duly executed exercise notice accompanied by payment in full for the number of shares of our common stock purchased upon such exercise (except in the case of a cashless exercise as discussed below). A holder (together with its affiliates) may not exercise any portion of such holder’s Common Warrant to the extent that the holder would own more than 4.99% (or, at the election of the purchaser, 9.99%) of the outstanding shares of common stock immediately after exercise, except that upon prior notice from the holder to us, the holder may increase the amount of ownership of outstanding shares of common stock after exercising the holder’s Common Warrants up to 9.99% of the number of shares of common stock outstanding immediately after giving effect to the exercise, as such percentage ownership is determined in accordance with the terms of the Common Warrants. No fractional shares of common stock will be issued in connection with the exercise of a Common Warrant. In lieu of fractional shares, we will either pay the holder an amount in cash equal to the fractional amount multiplied by the exercise price or round up to the next whole share.

Cashless exercise

If at any time after the six month anniversary of the closing date of this offering, there is no effective registration statement registering, or no current prospectus contained is available for, the resale of the shares of common stock issuable upon exercise of the Common Warrants by the Holder, then, in lieu of making the cash payment otherwise contemplated to be made to us upon such exercise in payment of the aggregate exercise price, the holder may elect instead to receive upon such exercise (either in whole or in part) the net number of shares of common stock determined according to a formula set forth in the Common Warrants.

Fundamental transactions

In the event of any fundamental transaction, as described in the Common Warrants and generally including any merger with or into another entity, sale of all or substantially all of our assets, tender offer or exchange offer, or reclassification of our shares of common stock, upon any subsequent exercise of a Common

S-27

TABLE OF CONTENTS

Warrant, the holder will have the right to receive as alternative consideration, for each share of common stock that would have been issuable upon such exercise immediately prior to the occurrence of such fundamental transaction, the number of shares of common stock of the successor or acquiring corporation of our company, if it is the surviving corporation, and any additional consideration receivable upon or as a result of such transaction by a holder of the number of shares of common stock for which the Common Warrant is exercisable immediately prior to such event.

Transferability

Subject to applicable laws, a Common Warrant or the rights thereunder may be transferred or assigned, in whole or in part. The ownership of the Common Warrants and any transfers of the Common Warrants will be registered in a warrant register maintained by the warrant agent. We will initially act as warrant agent.

Exchange listing

There is no trading market available for the Common Warrants on any securities exchange or nationally recognized trading system. We do not intend to list the Common Warrants on any securities exchange or nationally recognized trading system.

Right as a stockholder

Except as otherwise provided in the Common Warrants or by virtue of such holder’s ownership of shares of our common stock, the holders of the Common Warrants do not have the rights or privileges of holders of our common stock, including any voting rights, until they exercise their Common Warrants.

S-28

TABLE OF CONTENTS

PLAN OF DISTRIBUTION

Roth Capital Partners, LLC has agreed to act as our exclusive placement agent in connection with this offering subject to the terms and conditions of the placement agency agreement dated May 16, 2024. The placement agent is not purchasing or selling any of the securities offered by this prospectus supplement, nor is it required to arrange the purchase or sale of any specific number or dollar amount of securities, but has agreed to use its reasonable best efforts to arrange for the sale of all of the securities offered hereby. Therefore, we will enter into a securities purchase agreement directly with the investors in connection with this offering. The offering prices of the shares of common stock and Pre-Funded Warrants offered by this prospectus supplement have been determined based upon arm’s length negotiations between the investors and us. The shares of common stock and Pre-Funded Warrants sold pursuant to this prospectus supplement are being sold to institutional investors. The factors considered in determining the price of the shares of common stock and the Pre-Funded Warrants included the recent market price of our shares of common stock, the general condition of the securities market at the time of this offering, the history of, and the prospects, for the industry in which we compete, our past and present operations, and our prospects for future revenues.

We will deliver the securities being issued to each of the investors upon receipt of such investor’s funds for the purchase of the securities offered pursuant to this prospectus supplement. We expect to deliver the securities being offered pursuant to this prospectus supplement on or about May 21, 2024, subject to satisfaction of customary closing conditions.

We have agreed to indemnify the placement agent against specified liabilities, including liabilities under the Securities Act, and to contribute to payments the placement agent may be required to make in respect thereof.

Fees and Expenses

We have engaged Roth Capital Partners, LLC as our exclusive placement agent in connection with this offering. This offering is being conducted on a reasonable “best efforts” basis and the placement agent has no obligation to buy any of the securities from us or to arrange for the purchase or sale of any specific number or dollar amount of securities. We have agreed to pay the placement agent a fee based on the aggregate proceeds as set forth in the table below:

	Per Share			Per Pre-Funded Warrant			Total
Offering price	$2.46				$	2.45900		$	1,136,947.98
Placement agent’s fees(1)		$	0.1722		$	0.17213	$79,586.36
Proceeds to us, before expenses(2)		$	2.2878		$	2.28687		$	1,057,361.62

(1)

We have agreed to pay the placement agent a cash placement commission equal to 7% of the aggregate proceeds from this offering and the concurrent private placement.

(2)

The amount of offering proceeds to us presented in this table does not include proceeds from the exercise of the Common Warrants to be issued in the concurrent private placement.

We have also agreed to reimburse the placement agent at closing for legal and other non-accountable expenses incurred by them in connection with the offering in an aggregate amount up to $50,000. We estimate the total expenses payable by us for this offering, excluding the placement agent fees and expenses, will be approximately $140,000.

The placement agent may be deemed to be an underwriter within the meaning of Section 2(a)(11) of the Securities Act, and any commissions received by it and any profit realized on the resale of the shares sold by it while acting as principal might be deemed to be underwriting discounts or commissions under the Securities Act. As an underwriter, the placement agent would be required to comply with the requirements of the Securities Act and the Exchange Act, including, without limitation, Rule 415(a)(4) under the Securities Act and Rule 10b-5 and Regulation M under the Exchange Act. These rules and regulations may limit the timing of purchases and sales of shares by the placement agent acting as principal. Under these rules and regulations, the placement agent:

S-29

TABLE OF CONTENTS

•

may not engage in any stabilization activity in connection with our securities; and

•

may not bid for or purchase any of our securities or attempt to induce any person to purchase any of our securities, other than as permitted under the Exchange Act, until it has completed its participation in the distribution.

Listing

Our shares are listed on the Nasdaq Capital Market under the symbol “SEEL.” On May 16, 2024, the last reported sale price of our common stock on the Nasdaq Capital Market was $2.34 per share. There is no established public trading market for the Pre-Funded Warrants, and we do not expect a market to develop. In addition, we do not intend to list the Pre-Funded Warrants, nor do we expect Pre-Funded Warrants to be quoted, on the Nasdaq Capital Market or any other national securities exchange or any other nationally recognized trading system.

Lock-Up Agreements

Our executive officers and directors have agreed to be subject to a lock-up period that shall terminate on the date that is the 45 days following the closing of this offering. This means that, during the applicable lock-up period, such persons may not offer, sell, hypothecate, pledge or otherwise dispose of or enter into any transaction which is designed to, or might reasonably be expected to, result in the disposition (whether by actual disposition or effective economic disposition due to cash) directly or indirectly, any shares of common stock or any securities convertible into, or exercisable or exchangeable for, shares of common stock. Certain limited transfers are permitted during the lock-up period if the transferee agrees to these lock-up restrictions.

We have also agreed, in the securities purchase agreement, to a lock-up restriction on the issuance and sale of our securities until the date that is 45 days following the closing of this offering, subject to certain exempt issuances.

Further, we have agreed in the securities purchase agreement that we will not effect or enter into an agreement to effect any issuance of shares of common stock or common stock equivalents involving a variable rate transaction for a period of six months following the closing of this offering, subject to certain exceptions outlined in the securities purchase agreement.

Discretionary Accounts

The placement agent does not intend to confirm sales of the securities offered hereby to any accounts over which it has discretionary authority.

Other Activities and Relationships

The placement agent and certain of its affiliates are full service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory, investment management, investment research, principal investment, hedging, financing, and brokerage activities. The placement agent and certain of its affiliates have, from time to time, performed, and may in the future perform, various commercial and investment banking and financial advisory services for us and our affiliates, for which they received or will receive customary fees and expenses.

In the ordinary course of their various business activities, the placement agent and certain of its affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers, and such investment and securities activities may involve securities and/or instruments issued by us and our affiliates. If the placement agent or its affiliates have a lending relationship with us, they routinely hedge their credit exposure to us consistent with their customary risk management policies. The placement agent and its affiliates may hedge such exposure by entering into transactions that consist of either the purchase of credit default swaps or the creation of short positions in our securities or the securities of our affiliates, including potentially the shares of common stock and Pre-Funded Warrants offered hereby. Any such short positions could adversely affect future trading prices of the shares of common stock

S-30

TABLE OF CONTENTS

and Pre-Funded Warrants offered hereby. The placement agent and certain of its affiliates may also communicate independent investment recommendations, market color or trading ideas and/or publish or express independent research views in respect of such securities or instruments and may at any time hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

S-31

TABLE OF CONTENTS

LEGAL MATTERS

The validity of the shares of our common stock offered by this prospectus supplement will be passed upon for us by Brownstein Hyatt Farber Schreck, LLP, Las Vegas, Nevada. The validity of the Pre-Funded Warrants offered by this prospectus supplement will be passed upon for us by Paul Hastings LLP, Palo Alto, California. Ellenoff Grossman & Schole LLP, New York, New York is acting as counsel for the placement agent in connection with this offering.

EXPERTS

The consolidated financial statements of Seelos Therapeutics, Inc. as of December 31, 2023 and 2022, and for each of the years in the two-year period ended December 31, 2023, have been incorporated by reference herein in reliance upon the report of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing. The audit report covering the December 31, 2023 consolidated financial statements contains an explanatory paragraph that states that Seelos Therapeutics, Inc.’s recurring losses from operations and net capital deficiency raise substantial doubt about the entity’s ability to continue as a going concern. The consolidated financial statements do not include any adjustments that might result from the outcome of that uncertainty.

S-32

TABLE OF CONTENTS

WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC a registration statement under the Securities Act relating to the offering of these securities. The registration statement, including the attached exhibits, contains additional relevant information about us and the securities. This prospectus supplement does not contain all of the information set forth in the registration statement. You can obtain a copy of the registration statement from the SEC at the website address listed above. The registration statement and the documents referred to above are also available on our corporate website at www.seelostherapeutics.com under the heading “Investors”. Unless specifically listed above, the information contained on the SEC website or our website is not incorporated by reference into this prospectus supplement and you should not consider that information a part of this prospectus supplement.

We file annual, quarterly and other reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov. Our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, and Current Reports on Form 8-K, including any amendments to those reports, and other information that we file with or furnish to the SEC pursuant to Section 13(a) or 15(d) of the Exchange Act can also be accessed free of charge through the Internet. These filings will be available as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC.

S-33

TABLE OF CONTENTS

INFORMATION INCORPORATED BY REFERENCE

The SEC allows us to incorporate by reference into this prospectus supplement certain information we file with it, which means that we can disclose important information by referring you to those documents. The information incorporated by reference is considered to be a part of this prospectus supplement, and information that we file later with the SEC will automatically update and supersede information contained in this prospectus supplement and any accompanying prospectus supplement. We incorporate by reference the documents listed below that we have previously filed with the SEC:

(a)

Our Annual Report on Form 10-K for the fiscal year ended December 31, 2023, filed with the SEC on March 6, 2024, as amended by our Annual Report on Form 10-K/A filed with the SEC on April 29, 2024;

(b)

Our Quarterly Report on Form 10-Q for the quarter ended March 31, 2024, filed with the SEC on May 14, 2024;

(c)

Our Current Reports on Form 8-K filed with the SEC on (i) January 10, 2024, (ii) January 22, 2024, (iii) January 30, 2024, (iv) March 19, 2024, (v) March 28, 2024, (vi) May 3, 2024 and (vii) May 16, 2024; and

(d)

The description of our common stock set forth in our Registration Statement on Form 8-A (File No. 000-22245), filed with the SEC on April 10, 2000, including any amendments or reports filed for the purpose of updating such description, including the description of our common stock included as Exhibit 4.6 to our Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on March 6, 2024.

Any information in any of the foregoing documents will automatically be deemed to be modified or superseded to the extent that information in this prospectus supplement or in a later filed document that is incorporated or deemed to be incorporated herein by reference modifies or replaces such information.

All documents we file pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act on or after the date of this prospectus supplement and before the later of (1) the completion of the offering of the securities described in this prospectus supplement and (2) if applicable, the date we stop offering securities pursuant to this prospectus supplement will also be incorporated by reference in this prospectus supplement from the date of filing of such documents. Upon request, we will provide to each person, including any beneficial owner, to whom a prospectus supplement is delivered, without charge, a copy of any or all of the information that has been incorporated by reference in this prospectus supplement but not delivered with this prospectus supplement.

Notwithstanding the preceding, unless specifically stated to the contrary, none of the information that we disclose under Items 2.02 or 7.01 or, if related to Items 2.02 or 7.01, Item 9.01 of any Current Report on Form 8-K that we may, from time to time, furnish to the SEC will be incorporated by reference into, or otherwise included in, this prospectus supplement. The information contained in each of the documents incorporated by reference speaks only as of the date of such document. Any statement contained in a document incorporated by reference or deemed to be incorporated by reference herein, or contained in this prospectus supplement, shall be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained herein or in any subsequently filed document or report that also is incorporated by reference or is deemed to be incorporated by reference herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement.

We will provide to each person, including any beneficial owner, to whom a prospectus is delivered, without charge upon written or oral request, a copy of any or all of the documents that are incorporated by reference into this prospectus but not delivered with the prospectus supplement, including exhibits which are specifically incorporated by reference into such documents. You may obtain a copy of any of these documents at no cost, by writing or telephoning us at the following address or phone number:

Seelos Therapeutics, Inc.
300 Park Avenue, 2nd Floor
New York, New York 10022
Attn: Corporate Secretary
Phone: (646) 293-2100

S-34

TABLE OF CONTENTS

PROSPECTUS

[MISSING IMAGE: lg_seelostherapeutics-4clr.jpg]

$250,000,000
Common Stock
Preferred Stock
Debt Securities
Warrants
Units
Rights

We may offer and sell, from time to time in one or more offerings, up to $250,000,000 in the aggregate of any combination of the securities identified above from time to time in one or more offerings, either individually or in combination with other securities. We may also offer common stock or preferred stock upon conversion of debt securities, common stock upon conversion of preferred stock, or common stock, preferred stock, debt securities upon the exercise of warrants, units or rights.

Each time we offer and sell securities, we will provide a supplement to this prospectus that contains specific information about the offering and the amounts, prices and terms of the securities. We may also authorize one or more free writing prospectuses to be provided to you in connection with these offerings. The prospectus supplement and any related free writing prospectuses may also add, update or change information contained in this prospectus with respect to that offering. You should carefully read this prospectus and the applicable prospectus supplement and any related free writing prospectus, as well as any documents incorporated by reference, before you invest in any of our securities.

We may offer and sell the securities described in this prospectus and any prospectus supplement to or through one or more underwriters, dealers and agents, or directly to purchasers, or through a combination of these methods. If any underwriters, dealers or agents are involved in the sale of any of the securities, their names and any applicable purchase price, fee, commission or discount arrangement between or among them will be set forth, or will be calculable from the information set forth, in the applicable prospectus supplement. See the sections of this prospectus entitled “About this Prospectus” and “Plan of Distribution” for more information. No securities may be sold without delivery of this prospectus and the applicable prospectus supplement describing the method and terms of the offering of such securities.

Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading “Risk Factors” on page 10 of this prospectus, the applicable prospectus supplement and in any applicable free writing prospectuses, and under similar headings in the documents that are incorporated by reference into this prospectus.

Our common stock is currently listed on the Nasdaq Capital Market under the symbol “SEEL.” On December 15, 2023, the last reported sale price of our common stock was $1.56 per share. The applicable prospectus supplement will contain information, where applicable, as to any other listing on the Nasdaq Capital Market or any securities market or other exchange of the securities, if any, covered by the applicable prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities, or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is December 27, 2023.

TABLE OF CONTENTS

	Page
ABOUT THIS PROSPECTUS		1
INDUSTRY AND MARKET DATA		2
SUMMARY		3
RISK FACTORS		10
DISCLOSURE REGARDING FORWARD-LOOKING STATEMENTS		15
USE OF PROCEEDS		17
DESCRIPTION OF CAPITAL STOCK		18
DESCRIPTION OF DEBT SECURITIES		23
DESCRIPTION OF WARRANTS		32
DESCRIPTION OF UNITS		36
DESCRIPTION OF RIGHTS		37
LEGAL OWNERSHIP OF SECURITIES		38
PLAN OF DISTRIBUTION		41
LEGAL MATTERS		43
EXPERTS		43
WHERE YOU CAN FIND MORE INFORMATION		43
INCORPORATION OF DOCUMENTS BY REFERENCE		44

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we filed with the Securities and Exchange Commission (the “SEC”) utilizing a “shelf” registration process. Under this shelf registration process, we may offer and sell shares of our common stock and preferred stock, various series of debt securities, rights or warrants to purchase any of such securities and/or units consisting of any combination of such securities, either individually or in combination with other securities, in one or more offerings, up to a total dollar amount of $250,000,000. This prospectus provides you with a general description of the securities we may offer.

Each time we offer securities under this prospectus, we will provide a prospectus supplement that will contain more specific information about the terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement and any related free writing prospectus we have authorized for use in connection with a specific offering may also add, update or change any of the information contained in this prospectus or in the documents that we have incorporated by reference into this prospectus. We urge you to read carefully this prospectus, the applicable prospectus supplement and any free writing prospectuses we have authorized for use in connection with a specific offering, together with the information incorporated herein by reference as described under the section entitled “Incorporation of Documents by Reference”, before buying any of the securities being offered.

THIS PROSPECTUS MAY NOT BE USED TO CONSUMMATE A SALE OF SECURITIES UNLESS IT IS ACCOMPANIED BY A PROSPECTUS SUPPLEMENT.

You should rely only on the information contained in, or incorporated by reference into, this prospectus, the applicable prospectus supplement and any free writing prospectuses, along with the information contained in any free writing prospectuses we have authorized for use in connection with a specific offering. We have not authorized anyone to provide you with different or additional information. This prospectus is an offer to sell only the securities offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so.

The information appearing in this prospectus, the applicable prospectus supplement or any related free writing prospectus is accurate only as of the date on the front of the document and any information we have incorporated by reference is accurate only as of the date of the document incorporated by reference, regardless of the time of delivery of this prospectus, the applicable prospectus supplement or any related free writing prospectus, or any sale of a security. Our business, financial condition, results of operations and prospects may have changed since those dates.

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the heading “Where You Can Find More Information”.

TABLE OF CONTENTS

INDUSTRY AND MARKET DATA

Unless otherwise indicated, we have based the information concerning our industry contained in this prospectus and incorporated by reference herein on our general knowledge of and expectations concerning the industry, which involve risks and uncertainties and are subject to change based on various factors, including those discussed in the “Risk Factors” section of this prospectus and in the other information contained or incorporated by reference in this prospectus. These and other factors could cause the information concerning our industry to differ materially from those expressed in this prospectus and incorporated by reference herein.

TABLE OF CONTENTS

SUMMARY

This summary highlights selected information that is presented in greater detail elsewhere in this prospectus or in the documents incorporated by reference in this prospectus. Because it is only a summary, it does not contain all of the information you should consider before investing in our common stock, preferred stock, debt securities, warrants, units or rights, and it is qualified in its entirety by, and should be read in conjunction with, the more detailed information included elsewhere in this prospectus. Before you decide whether to purchase shares of our common stock or preferred stock, or our debt securities, warrants, units or rights, you should read this entire prospectus, the applicable prospectus supplement and any related free writing prospectus carefully, including the risks of investing in our securities discussed under the heading “Risk Factors” contained in the applicable prospectus supplement and any related free writing prospectus, and under similar headings in the other documents that are incorporated by reference into this prospectus. You should also carefully read the information incorporated by reference into this prospectus, including our financial statements, and the exhibits to the registration statement of which this prospectus is a part. Unless the context otherwise requires, the terms “Seelos,” “the Company,” “we,” “us” and “our” in this prospectus refer to Seelos Therapeutics, Inc. and its subsidiaries.

Overview

Our product development pipeline is as follows:

Product	Indication	Development Phase	Development Status
SLS-002 Intranasal Racemic Ketamine	Acute Suicidal Ideation and Behavior (“ASIB”) in Major Depressive Disorder (“MDD”)	Phase II	Completed open-label patient enrollment and announced the initial topline data from Part 1 of the proof-of-concept (“PoC”) study on May 17, 2021; enrollment of Part 2 of a Phase II study closed in June 2023; topline data for Part 2 announced on September 20, 2023
SLS-005 IV Trehalose	Amyotrophic Lateral Sclerosis (“ALS)”	Phase II/III	Completed enrollment of final participants in February 2023 in the registrational study; data readout expected in the first quarter of 2024
	Spinocerebellar Ataxia (“SCA”)	Phase IIb/III	Announced dosing of the first participant in the registrational study in October 2022; enrollment of additional patients temporarily paused on March 29, 2023
	Huntington’s Disease (“HD”) and Alzheimer’s Disease (“AD”)	Phase II	Obtaining biomarker activity

TABLE OF CONTENTS

Product	Indication	Development Phase	Development Status
SLS-004 Gene Therapy	Parkinson’s Disease (“PD”)	Pre-IND	Preclinical in vivo studies ongoing; announced partial results from a study demonstrating downregulation of α-synuclein in December 2022; currently analyzing data while temporarily pausing additional spend
SLS-007 Peptide Inhibitor	PD	Pre-IND	Preclinical study completed and analysis of the results ongoing; next steps for development of this program will be decided in concert with SLS-004 results and readouts, as both target the same pathway upstream; temporarily pausing additional spend
SLS-009	HD, AD, ALS	Pre-IND	Preclinical in vivo studies ongoing

Lead Programs

The clinical development program for SLS-002 includes two parallel healthy volunteer studies (Phase I). We announced interim data from our Phase I study of SLS-002 during the quarterly period ended March 31, 2020. As a result, in March 2020, we completed a Type C meeting with the U.S. Food and Drug Administration (the “FDA”) and received guidance to conduct a Phase II PoC study of SLS-002 for ASIB in adults with MDD, to support the further clinical development of this product candidate, together with nonclinical data under development.

TABLE OF CONTENTS

topline data from Part 1 of the PoC study, the open-label cohort, of our study of SLS-002 (intranasal racemic ketamine), demonstrating a significant treatment effect and a well-tolerated safety profile for ASIB in patients with MDD. This study enrolled 17 subjects diagnosed with MDD requiring psychiatric hospitalization due to significant risk of suicide with a baseline score of ≥ 28 points on the Montgomery-Åsberg Depression Rating Scale (“MADRS”), a score of 5 or 6 on MADRS Item-10, a score of ≥ 15 points on the Sheehan-Suicidality Tracking Scale (S-STS) and a history of previous suicide attempt(s), as confirmed on the Columbia Suicide Severity Rating Scale (C-SSRS) with a history of at least one actual attempt, or if the attempt was interrupted or aborted, is judged to have been serious in intent. SLS-002 demonstrated a 76.5% response rate (response meaning 50% reduction from baseline) in the primary endpoint on MADRS 24 hours after first dose, with a mean reduction in total score from 39.4 to 14.5 points.

SLS-005 is IV trehalose, a protein stabilizer that crosses the blood-brain barrier and activates autophagy and the lysosomal pathway. Based on preclinical and in vitro studies, there is a sound scientific rationale for developing trehalose for the treatment of ALS, SCA and other indications such as Sanfilippo Syndrome. Trehalose is a low molecular weight disaccharide (0.342 kDa) that protects against pathological processes in cells. It has been shown to penetrate muscle and cross the blood-brain barrier. In animal models of several diseases associated with abnormal cellular protein aggregation, it has been shown to reduce pathological aggregation of misfolded proteins as well as to activate autophagy pathways through the activation of Transcription Factor EB (“TFEB”), a key factor in lysosomal and autophagy gene expression. Activation of TFEB is an emerging therapeutic target for a number of diseases with pathologic accumulation of storage material.

Trehalose 90.5 mg/mL IV solution has demonstrated promising clinical potential in prior Phase II clinical development for oculopharyngeal muscular dystrophy (“OPMD”) and spinocerebellar ataxia type 3 (“SCA3”), also known as Machado Joseph disease, with no significant safety signals to date and encouraging efficacy results. Pathological accumulation of protein aggregates within cells, whether in the CNS or in muscle, and eventually leads to loss of function and ultimately cell death. Prior preclinical studies indicate that this platform has the potential to prevent mutant protein aggregation in other devastating PolyA/PolyQ diseases.

We own three U.S. patents for parenteral administration of trehalose for patients with OPMD and SCA3, all of which are expected to expire in 2034. In addition, Orphan Drug Designation (“ODD”) for OPMD and SCA3 has been secured in the United States and in the European Union (“EU”). In February 2019, we assumed a collaborative agreement, turned subsequently into a research grant, with Team Sanfilippo Foundation (“TSF”), a nonprofit medical research foundation founded by parents of children with Sanfilippo Syndrome. On April 30, 2020, we were granted ODD for SLS-005 in Sanfilippo Syndrome from the FDA. SLS-005 was previously granted ODD from the FDA and European Medicines Agency (the “EMA”) for SCA3 and OPMD as well as Fast Track designation for OPMD. On August 25, 2020, we were issued U.S. patent number 10,751,353 titled “COMPOSITIONS AND METHODS FOR TREATING AN AGGREGATION DISEASE OR DISORDER” which relates to trehalose (SLS-005). The issued patent covers the method of use for trehalose (SLS-005) formulation for treating a disease or disorder selected from any one of the following: spinal and bulbar muscular atrophy, dentatombral-pallidoluysian atrophy, Pick’s disease, corticobasal degeneration, progressive supranuclear palsy, frontotemporal dementia or parkinsonism linked to chromosome 17. On May 15, 2020, we were granted Rare Pediatric Disease Designation (“RPDD”) for SLS-005 in Sanfilippo Syndrome from the FDA. RPDD is an incentive program created under the Federal Food, Drug, and Cosmetic Act to encourage the development of new therapies for the prevention and treatment of certain rare pediatric diseases. On May 27, 2021, we announced that we were granted ODD for SLS-005 in ALS from the EMA. In December 2020, we announced the selection of SLS-005 for the Healey ALS platform trial led by Harvard Medical School, Massachusetts. The Healey ALS platform trial is designed to study multiple potential treatments for ALS simultaneously. The platform trial model aims to greatly accelerate the study access, reduce costs and shorten development timelines. On February 28, 2022, we announced the dosing of the first

TABLE OF CONTENTS

participants in the Healey ALS platform trial. In November 2021, we announced the FDA acceptance of an IND and grant of Fast Track designation for SLS-005 for the treatment of SCA. In July 2022, we also announced dosing of the first patient in an open-label basket study in Australia for the treatment of patients with ALS, SCA, and Huntington’s disease (“HD”). In October 2022, we also announced the dosing of the first participant in the registrational Phase II/III study for the treatment of SCA. In March 2023, we announced that in order to focus the majority of our resources on the Phase II study of SLS-002 (intranasal racemic ketamine) for ASIB in adults with MDD and the fully enrolled Phase II/III study of SLS-005 in ALS, we have temporarily paused additional enrollment of patients in the SLS-005-302 study in SCA. Patients already enrolled will continue in the study and data will continue to be collected in order to make decisions for resuming enrollment in the future. This temporary pause has been implemented as a business decision due to financial considerations, and is not based on any data related to safety or therapeutic effects.

Strategy and Ongoing Programs

SLS-005: We completed enrollment in February 2023 for a clinical study in ALS and began enrollment for a clinical study in SCA in October 2022. In December 2020, we announced the selection of SLS-005 for the Healey ALS platform trial led by Harvard Medical School, Massachusetts. The Healey ALS platform trial is designed to study multiple potential treatments for ALS simultaneously. The platform trial model aims to greatly accelerate the study access, reduce costs, and shorten development timelines. On February 28, 2022, we announced dosing of the first participants in the Healey ALS platform trial. In February 2023, we announced the completion of enrollment of the study and data readout is expected in the first quarter of 2024.

During 2022, we received regulatory approval in Australia to commence a study pursuing the collection of certain biomarker data in patients with Alzheimer’s Disease.

We are also continuing to consider trials in Sanfilippo Syndrome and are seeking more natural history data based on the guidance from regulatory agencies.

In March 2023, we announced that in order to focus the majority of our resources on the ongoing Phase II study of SLS-002 (intranasal racemic ketamine) for ASIB in patients with MDD and the fully enrolled Phase II/III study of SLS-005 in ALS, we have temporarily paused additional enrollment of patients in the SLS-005-302 study in SCA. Patients already enrolled will continue in the study and data will continue to be collected in order to make decisions for resuming enrollment in the future. This temporary pause has been implemented as a business decision due to financial considerations, and is not based on any data related to safety or therapeutic effects.

TABLE OF CONTENTS

PD patient, modified the expression on α-synuclein and exhibited reversal of the disease-related cellular-phenotype characteristics of the neurons. The role of mutated SNCA in PD pathogenesis and the need to maintain the normal physiological levels of α-synuclein protein emphasize the yet unmet need to develop new therapeutic strategies, such as SLS-004, targeting the regulatory mechanism of α-synuclein expression. On May 28, 2020, we announced the initiation of a preclinical study of SLS-004 in PD through an all-in-one lentiviral vector targeting the SNCA gene. We are constructing a bimodular viral system harboring an endogenous α-synuclein transgene and inducible regulated repressive CRISPR/dCas9-unit to achieve suppression of PD-related pathologies. On July 7, 2021, we announced positive in vivo data demonstrating down-regulation of SNCA mRNA and protein expression under this study. In December 2022, we announced in vivo data demonstrating that a single dose of SLS-004 was successful in reversing some of the key hallmarks of PD in a humanized mouse model. These findings observed in an in vivo humanized PD model validate and extend prior findings from in vitro data using SLS-004. SLS-004 demonstrated therapeutically desirable change in SNCA expression that led to reversing the key hallmarks of PD in the model towards normal physiological levels, indicating disease modifying effect of single dose administration of SLS-004, a CRISPR/dCas-9 based gene therapy for PD. We have halted any further investment in this program until additional funding is received.

SLS-007 is a rationally designed peptide-based approach, targeting the nonamyloid component core (“NACore”) of α-synuclein to inhibit the protein from aggregation. Recent in vitro and cell culture research has shown that SLS-007 has the ability to stop the propagation and seeding of α- synuclein aggregates. We will evaluate the potential for in vivo delivery of SLS-007 in a PD transgenic mice model. The goal will be to establish in vivo pharmacokinetics/pharmacodynamics and target engagement parameters of SLS-007, a family of anti- α -synuclein peptidic inhibitors. On June 25, 2020, we announced the initiation of a preclinical study of SLS-007 in PD delivered through an adeno-associated viral (“AAV”) vector targeting the non-amyloid component core of α-synuclein. We have initiated an in vivo preclinical study of SLS-007 in rodents to assess the ability of two specific novel peptides, S62 and S71, delivered via AAV1/2 vector, to protect dopaminergic function in the AAV A53T overexpression mice model of PD. Production of AAV1/2 vectors encoding each of the two novel peptides incorporating hemagglutinin tags has already been completed. The results are currently being analyzed and the next steps for development of this program will be decided in concert with SLS-004 results and readouts, as both target the same pathway upstream.

We intend to become a leading biopharmaceutical company focused on neurological and psychiatric disorders, including orphan indications. Our business strategy includes:

•

advancing SLS-002 in ASIB in MDD and post-traumatic stress disorder;

•

advancing SLS-004 in PD;

•

advancing SLS-005 in ALS, SCA, HD and Sanfilippo Syndrome;

•

advancing new formulations of SLS-005 in neurological diseases; and

•

acquiring synergistic assets in the CNS therapy space through licensing and partnerships.

Nasdaq Minimum Bid Notice and Minimum Market Value Notice

On November 1, 2023, we received written notice (the “First Notice”) from The Nasdaq Stock Market LLC (“Nasdaq”) indicating that, for the last 30 consecutive business days, the bid price for our common stock had closed below the minimum $1.00 per share requirement for continued listing on the Nasdaq Capital

TABLE OF CONTENTS

Market under Nasdaq Listing Rule 5550(a)(2) (“Rule 5550(a)(2)”). In accordance with Nasdaq Listing Rule 5810(c)(3)(A), we have been provided an initial period of 180 calendar days, or until April 29, 2024, to regain compliance. The First Notice states that the Nasdaq staff will provide written confirmation that we have achieved compliance with Rule 5550(a)(2) if at any time before April 29, 2024, the bid price of our common stock closes at $1.00 or more per share for a minimum of ten consecutive business days.

In addition, on November 2, 2023, we received written notice (the “Second Notice” and, together with the First Notice, the “Notices”) from Nasdaq indicating that, for the last 32 consecutive business days, the market value of our listed securities has been below the minimum requirement of $35 million for continued listing on the Nasdaq Capital Market under Nasdaq Listing Rule 5550(b)(2) (“Rule 5550(b)(2)”). In accordance with Nasdaq Listing Rule 5810(c)(3)(C), we have been provided a period of 180 calendar days, or until April 30, 2024, to regain compliance. The Second Notice states that the Nasdaq staff will provide written notification that we have achieved compliance with Rule 5550(b)(2) if at any time before April 30, 2024, the market value of our common stock closes at $35 million or more for a minimum of ten consecutive business days.

The Notices have no immediate effect on the listing or trading of our common stock and the common stock will continue to trade on the Nasdaq Capital Market under the symbol “SEEL.”

If we do not regain compliance with Rule 5550(a)(2) by April 29, 2024, we may be eligible for an additional 180 calendar day compliance period. To qualify, we would be required to meet the continued listing requirement for market value of publicly held shares and all other initial listing standards for the Nasdaq Capital Market, with the exception of the bid price requirement, and would need to provide written notice to Nasdaq of our intention to cure the deficiency during the second compliance period, effectuating an additional reverse stock split, if necessary. However, if it appears to the Nasdaq staff that we will not be able to cure the deficiency, or if we are otherwise not eligible, Nasdaq would notify us that our securities will be subject to delisting. Additionally, if we do not regain compliance with Rule 5550(b)(2) by April 30, 2024, we will receive written notification that our securities are subject to delisting. In the event we receive any such notification, we may appeal the Nasdaq staff’s determination to delist our securities, but there can be no assurance the Nasdaq staff would grant any request for continued listing.

We intend to monitor the bid price and market value of our common stock and consider available options if our common stock does not trade at a level likely to result in us regaining compliance with Nasdaq’s minimum bid price rule by April 29, 2024, or the minimum market value of listed securities rule by April 30, 2024, which may include, among other options, effectuating an additional reverse stock split. There can be no assurance that we will be able to regain compliance with Nasdaq’s minimum bid price rule or Nasdaq’s minimum market value of listed securities rule or that we will otherwise be in compliance with the other listing standards for the Nasdaq Capital Market.

Recent Developments

Reverse Stock Split

On November 27, 2023, we filed a Certificate of Change with the Secretary of State of the State of Nevada to (i) effect a 1-for-30 reverse stock split (the “Reverse Stock Split”) of our issued and outstanding shares of common stock, effective at 12:01 a.m. Eastern Time, on November 28, 2023, and (ii) decrease the number of total authorized shares of our common stock from 480,000,000 shares to 16,000,000 shares. Our common stock begin trading on a Reverse Stock Split-adjusted basis on the Nasdaq Capital Market at the opening of the market on November 28, 2023.

Public Offering

Pursuant to an underwriting agreement (the “Underwriting Agreement”) with Titan Partners Group, LLC, a division of American Capital Partners, LLC (“Titan”), on December 1, 2023, we sold to Titan, in an underwritten public offering (i) 1,781,934 shares (the “Shares”) of our common stock, (ii) pre-funded warrants to purchase up to 2,422,612 shares of common stock (the “Pre-Funded Warrants”) and (iii) accompanying common stock warrants to purchase up to 4,204,546 shares of common stock (the “Common Warrants” and together with the Pre-Funded Warrants, the “Warrants”). The combined public

TABLE OF CONTENTS

offering price for each share of common stock and accompanying Common Warrant to purchase one share of common stock was $1.32 and the combined public offering price for each share of common stock subject to a Pre-Funded Warrant and accompanying Common Warrant to purchase one share of common stock was $1.319. The net proceeds to us were approximately $5 million, after deducting the underwriting discounts and commissions and other estimated offering expenses payable by us.

The Pre-Funded Warrants were exercisable immediately and had an exercise price of $0.001 per share. As of December 15, 2023, the Pre-Funded Warrants have been exercised in full.

The per share exercise price for the Common Warrants is $1.32, subject to adjustment as provided therein. The Common Warrants were exercisable immediately and expire on December 1, 2028. Each holder of a Common Warrant does not have the right to exercise any portion of its Common Warrant if the holder, together with its affiliates, would beneficially own more than 4.99% (or, at the election of the purchaser, 9.99%) of the number of shares of the common stock outstanding immediately after giving effect to such exercise (the “Common Warrant Beneficial Ownership Limitation”); provided, however, that upon 61 days’ prior notice to the Company, the holder may increase the Common Warrant Beneficial Ownership Limitation, but not to above 9.99%. The exercise price and number of shares of common stock issuable upon the exercise of the Common Warrants is subject to adjustment in the event of any stock dividend, stock split, reverse stock split, recapitalization, reorganization or similar transaction, as described in the Common Warrants. If a registration statement covering the issuance of the shares of common stock issuable upon exercise of the Common Warrants is not available for the issuance, then the holders may exercise the Common Warrants by means of a “cashless exercise.”

Corporate Information

Our principal executive offices are located at 300 Park Avenue, 2nd Floor, New York, NY 10022, and our telephone number is (646) 293-2100. Our website is located at www.seelostherapeutics.com. Any information contained on, or that can be accessed through, our website is not incorporated by reference into, nor is it in any way part of, this prospectus and should not be relied upon in connection with making any decision with respect to an investment in our securities. We are required to file annual, quarterly and current reports, proxy statements and other information with the SEC. You may obtain any of the documents filed by us with the SEC at no cost from the SEC’s website at http://www.sec.gov.

We are a “smaller reporting company” as defined in Rule 12b-2 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) and have elected to take advantage of certain of the scaled disclosure available for smaller reporting companies in this prospectus as well as our filings under the Exchange Act.

TABLE OF CONTENTS

RISK FACTORS

Investing in any securities offered pursuant to this prospectus, the applicable prospectus supplement and any related free writing prospectus involves a high degree of risk. Before making an investment decision, you should carefully consider the risks described below, under “Risk Factors” in the applicable prospectus supplement, any related free writing prospectus and in our most recent Annual Report on Form 10-K, or in any updates in our Quarterly Reports on Form 10-Q, together with all of the other information appearing in or incorporated by reference into this prospectus, the applicable prospectus supplement and any related free writing prospectus, before deciding whether to purchase any of the securities being offered. Our business, financial condition or results of operations could be materially adversely affected by any of these risks. The occurrence of any of these risks might cause you to lose all or part of your investment in the offered securities.

Risks Related to the Company

On November 23, 2021, we issued and sold to Lind Global Asset Management V, LLC (“Lind”) a convertible promissory note in an aggregate principal amount of $22.0 million for an aggregate purchase price of $20.0 million (the “Convertible Promissory Note”). The Convertible Promissory Note contains certain restrictive covenants and event of default provisions, including restrictions on certain sales or other dispositions of company assets, restrictions on entering into certain variable-rate transactions and a covenant requiring us to maintain an aggregate minimum balance equal to 50% of the then-outstanding principal amount under the Convertible Promissory Note or more in cash and cash equivalents commencing on March 28, 2024. As of December 15, 2023, the outstanding principal amount of the Convertible Promissory Note was approximately $13.9 million. If we are not able to comply or regain compliance with any of the covenants in, or otherwise trigger a default under, the Convertible Promissory Note, Lind could declare the Convertible Promissory Note immediately due and payable, which would require us to pay 120% of the outstanding principal amount of the Convertible Promissory Note and would have a material adverse effect on our liquidity, financial condition, operating results, business and prospects, and could cause the price of our common stock to decline. In addition, since the borrowings under the Convertible Promissory Note are secured by a first priority lien on our assets, Lind would be able to foreclose on our assets if we do not cure any default or pay any amounts due and payable under the Convertible Promissory Note. In addition, Lind has the right to convert the then-outstanding principal amount of the Convertible Promissory Note into shares of our common stock at the lower of (x) the then-current conversion price (which is currently $180.00 per share, subject to adjustment in certain circumstances as described in the Convertible Promissory Note) and (y) 85% of the average of the five lowest daily volume weighted-average price of our common stock during the 20 trading days prior to the delivery by Lind of a notice of conversion.

We have a limited number of shares of common stock available for issuance, which may limit our ability to raise capital.

We currently have 16,000,000 authorized shares of common stock under our Amended and Restated Articles of Incorporation, as amended. As of December 15, 2023, we had 9,794,594 shares of common stock issued and outstanding and 6,176,468 shares of common stock were reserved for issuance under long-term equity incentive plans, employee stock purchase plan, the Convertible Promissory Note and warrants to purchase common stock. We need stockholder approval to increase the number of authorized shares of our common stock. On December 15, 2023, we filed a definitive proxy statement related to a special meeting of our stockholders to be held on January 10, 2024 (the “2024 Special Meeting”). At the 2024 Special Meeting, our stockholders are being asked to approve an increase in the number of shares of common stock we are authorized to issue from 16 million shares of common stock to 400 million shares of common stock. There can be no assurance that this proposal will be approved by our stockholders. If this proposal is not approved, the limited number of shares available for issuance may limit our ability to raise capital in the equity markets and satisfy obligations with shares instead of cash, which could adversely impact our ability to fund our business and operations.

TABLE OF CONTENTS

Risks Related to Owning Our Common Stock

The market price of our common stock has been and will likely continue to be volatile.

The trading price of our common stock has been and is likely to continue to be volatile. For example, in 2022 our closing stock price ranged from $15.24 to $51.31 per share (such prices reflect the Reverse Stock Split), during the quarter ended September 30, 2023, our closing stock price ranged from $4.80 to $49.20 per share and, from October 2, 2023 to December 15, 2023, our closing stock price ranged from $1.25 to $6.4566 per share (such prices reflect the Reverse Stock Split). Our stock price could be subject to wide fluctuations in response to a variety of factors, including the following:

•

results from, and any delays in, planned clinical trials for our product candidates, or any other future product candidates, and the results of trials of competitors or those of other companies in our market sector;

•

any delay in filing an NDA for any of our product candidates and any adverse development or perceived adverse development with respect to the FDA’s review of that NDA;

•

significant lawsuits, including patent or stockholder litigation;

•

inability to obtain additional funding;

•

failure to successfully develop and commercialize our product candidates;

•

changes in laws or regulations applicable to our product candidates;

•

inability to obtain adequate product supply for our product candidates, or the inability to do so at acceptable prices;

•

unanticipated serious safety concerns related to any of our product candidates;

•

adverse regulatory decisions;

•

introduction of new products or technologies by our competitors;

•

failure to meet or exceed drug development or financial projections we provide to the public;

•

failure to meet or exceed the estimates and projections of the investment community;

•

the perception of the biopharmaceutical industry by the public, legislatures, regulators, and the investment community;

•

announcements of significant acquisitions, strategic partnerships, joint ventures or capital commitments by us or our competitors;

•

disputes or other developments relating to proprietary rights, including patents, litigation matters and our ability to obtain patent protection for our licensed and owned technologies;

•

additions or departures of key scientific or management personnel;

•

changes in the market valuations of similar companies;

•

general economic and market conditions and overall fluctuations in the U.S. equity market, including any potential recession or economic downturn;

•

public health crises, pandemics, and epidemics, such as the COVID-19 pandemic;

•

sales of our common stock by us or our stockholders in the future; and

•

the trading volume of our common stock.

In addition, the stock market in general, and small biopharmaceutical companies in particular, have experienced extreme price and volume fluctuations that have often been unrelated or disproportionate to the operating performance of these companies. Broad market and industry factors may negatively affect the market price of our common stock, regardless of our actual operating performance. Further, a decline in the financial markets and related factors beyond our control may cause our stock price to decline rapidly and unexpectedly.

TABLE OF CONTENTS

Moreover, in the past, stockholders have initiated class action and other lawsuits against pharmaceutical and biotechnology companies following periods of volatility in the market prices of these companies’ stock or periods of decreased stock price. Such litigation, if instituted against us, could cause us to incur substantial costs and divert management’s attention and resources from our business. We are not currently party to any such litigation. However, on October 10, 2023, Empery Asset Management, LP (“Empery”) issued a press release disclosing that it transmitted a letter to our management and board of directors claiming that our Chief Executive Officer allegedly made material misrepresentations regarding the Phase II study of SLS-002 (intranasal racemic ketamine) for ASIB in patients with MDD. We disagree with the statements and allegations in the press release and believe that we have good and substantial defenses to the claims alleged by Empery, but there is no guarantee that Empery will not bring a lawsuit against us or that we will prevail in any such litigation, if initiated.

On November 21, 2022, we received a written notice from Nasdaq indicating that, for the last thirty consecutive business days, the bid price for our common stock had closed below the minimum $1.00 per share requirement for continued listing on the Nasdaq Capital Market under Nasdaq Listing Rule 5550(a)(2) (“Rule 5550(a)(2”). In accordance with Nasdaq Listing Rule 5810(c)(3)(A), we were provided an initial period of 180 calendar days, or until May 22, 2023, to regain compliance. On May 23, 2023, Nasdaq provided a notice to us that we had not regained compliance with Rule 5550(a)(2) and were not eligible for a second 180 calendar day compliance period as we did not comply with the minimum $5,000,000 stockholder’s equity requirement for initial listing on the Nasdaq Capital Market. We timely submitted a hearing request before the Nasdaq Hearings Panel, and also provided the Nasdaq Hearings Panel with a plan to regain compliance, which plan included a commitment and intent to conduct a reverse stock split of our common stock to regain compliance with Rule 5550(a)(2). On June 26, 2023, we received a letter from Nasdaq granting us a temporary exception until October 31, 2023 to regain compliance with Rule 5550(a)(2) by evidencing a closing bid price of $1.00 or more per share for a minimum of ten consecutive trading sessions. On July 24, 2023, we received a letter from Nasdaq notifying us that we regained compliance with Rule 5550(a)(2), as required by the Nasdaq Hearings Panel and the Compliance Plan. This letter further noted that the Nasdaq Hearings Panel determined to continue the listing of our common stock.

On November 1, 2023, we received an additional written notice from Nasdaq indicating that, for the last 30 consecutive business days, the bid price for our common stock had closed below the minimum $1.00 per share requirement for continued listing on the Nasdaq Capital Market under Rule 5550(a)(2). In accordance with Nasdaq Listing Rule 5810(c)(3)(A), we have been provided an initial period of 180 calendar days, or until April 29, 2024, to regain compliance. The Nasdaq staff will provide written confirmation that we have achieved compliance with Rule 5550(a)(2) if at any time before April 29, 2024, the bid price of our common stock closes at $1.00 or more per share for a minimum of ten consecutive business days. In addition, on November 2, 2023, we received an additional written notice from Nasdaq indicating that, for the last 32 consecutive business days, the market value of our listed securities has been below the minimum requirement of $35 million for continued listing on the Nasdaq Capital Market under Nasdaq Listing Rule 5550(b)(2) (“Rule 5550(b)(2)”). In accordance with Nasdaq Listing Rule 5810(c)(3)(C), we have been provided a period of 180 calendar days, or until April 30, 2024, to regain compliance. The Nasdaq staff will

TABLE OF CONTENTS

provide written notification that we have achieved compliance with Rule 5550(b)(2) if at any time before April 30, 2024, the market value of our common stock closes at $35 million or more for a minimum of ten consecutive business days.

On November 27, 2023, we filed a Certificate of Change (the “Certificate of Change”) with the Secretary of State of the State of Nevada to (i) effect a 1-for-30 reverse stock split (the “Reverse Stock Split”) of our issued and outstanding shares of common stock, effective at 12:01 a.m. Eastern Time, on November 28, 2023, and (ii) decrease the number of total authorized shares of our common stock from 480,000,000 shares to 16,000,000 shares. The Reverse Stock Split was intended, among other reasons, to allow us to achieve the requisite increase in the market price of our common stock to be in compliance with the minimum bid price of Nasdaq. However, there can be no assurance that the price of our common stock will stay above the minimum requirements for the time period required by Nasdaq in order to regain compliance with the rule.

We will continue to monitor the bid price and market value of our common stock and consider available options if our common stock does not trade at a level likely to result in our regaining compliance with the Nasdaq Capital Market’s minimum bid price rule by April 29, 2024, or the minimum market value of listed securities rule by April 30, 2024. There can be no assurances that we will be able to regain compliance with Nasdaq’s minimum bid price rule or Nasdaq’s minimum market value of listed securities rule or that we will otherwise be in compliance with the other listing standards for the Nasdaq Capital Market. If we do not regain compliance with Rule 5550(a)(2) by April 29, 2024, we may be afforded a second 180 calendar day period to regain compliance. To qualify, we would be required to meet the continued listing requirement for market value of publicly held shares and all other initial listing standards for the Nasdaq Capital Market, except for the minimum bid price requirement. In addition, we would be required to notify Nasdaq of our intent to cure the deficiency during the second compliance period, which may include, if necessary, implementing an additional reverse stock split. However, if it appears to the Nasdaq staff that we will not be able to cure the deficiency, or if we are otherwise not eligible, Nasdaq would notify us that our securities will be subject to delisting. Additionally, if we do not regain compliance with Rule 5550(b)(2) by April 30, 2024, we will receive written notification that our securities are subject to delisting. In the event we receive any such notification, we may appeal the Nasdaq staff’s determination to delist our securities, but there can be no assurances that the Nasdaq staff would grant any request for continued listing.

In addition, we have previously received similar notices from Nasdaq that our bid price of our common stock had closed below the minimum $1.00 per share requirement for continued listing on the Nasdaq Capital Market under Rule 5550(a)(2) based on deficiencies in March and April 2020 and October and November 2022, and that the market value of our listed securities has been below the minimum requirements of $35 million for continued listing on the Nasdaq Capital Market under Rule 5550(b)(2) based on deficiencies in March and April 2020. Even though we previously regained compliance with the Nasdaq Capital Market’s minimum closing bid price requirement, and minimum market value of listed securities requirement, there is no guarantee that we will remain in compliance with such listing requirements or other listing requirements in the future. Any failure to maintain compliance with continued listing requirements of the Nasdaq Capital Market could result in delisting of our common stock from the Nasdaq Capital Market and negatively impact our company and holders of our common stock, including by reducing the willingness of investors to hold our common stock because of the resulting decreased price, liquidity and trading of our common stock, limited availability of price quotations and reduced news and analyst coverage. Delisting may adversely impact the perception of our financial condition, cause reputational harm with investors, our employees and parties conducting business with us and limit our access to debt and equity financing.

We cannot predict the effect that the Reverse Stock Split will have on the market price for shares of our common stock.

TABLE OF CONTENTS

DISCLOSURE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus, any accompanying prospectus supplement and the documents incorporated by reference in this prospectus contain “forward-looking statements” by us within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”) and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), which statements involve substantial risks and uncertainties. These forward-looking statements are intended to be covered by the safe harbor for forward-looking statements provided by the Private Securities Litigation Reform Act of 1995. Forward-looking statements generally relate to future events or our future financial or operating performance. In some cases, you can identify forward-looking statements because they contain words such as “may,” “will,” “should,” “expects,” “plans,” “anticipates,” “could,” “intends,” “target,” “projects,” “contemplates,” “believes,” “estimates,” “predicts,” “potential” or “continue” or the negative of these words or other similar terms or expressions that concern our expectations, strategy, plans or intentions. Forward-looking statements contained in this prospectus, any accompanying prospectus supplement and the documents incorporated by reference in this prospectus include, but are not limited to, statements about:

•

risks and uncertainties associated with our actual and proposed research and development activities, including our clinical trials and preclinical studies;

•

the timing or likelihood of regulatory filings and approvals or of alternative regulatory pathways for our product candidates;

•

the potential market opportunities for commercializing our product candidates;

•

our expectations regarding the potential market size and the size of the patient populations for our product candidates, if approved for commercial use, and our ability to serve such markets;

•

estimates of our expenses, future revenue, capital requirements and our needs for additional financing;

•

our ability to continue as a going concern;

•

our ability to maintain the listing of our common stock on the Nasdaq Capital Market;

•

our ability to develop, acquire and advance our product candidates into, and successfully complete, clinical trials and preclinical studies and obtain regulatory approvals;

•

the implementation of our business model and strategic plans for our business and product candidates;

•

the initiation, cost, timing, progress and results of future and current preclinical studies and clinical trials, and our research and development programs;

•

the terms of future licensing arrangements, and whether we can enter into such arrangements at all;

•

timing and receipt or payments of licensing and milestone revenues or payments, if any;

•

regulatory developments in the United States and foreign countries;

•

the performance of our third party suppliers and manufacturers;

•

our ability to maintain and establish collaborations or obtain additional funding;

•

the success of competing therapies that are currently or may become available;

•

our financial performance; and

•

developments and projections relating to our competitors and our industry.

We caution you that the forward-looking statements highlighted above do not encompass all of the forward-looking statements made in this prospectus, any accompanying prospectus supplement and the documents incorporated by reference into this prospectus.

We have based the forward-looking statements contained in this prospectus, the applicable prospectus supplement and any related free writing prospectus and in the documents incorporated by reference into

TABLE OF CONTENTS

this prospectus primarily on our current expectations and projections about future events and trends that we believe may affect our business, financial condition, results of operations and prospects. The outcomes of the events described in these forward-looking statements are subject to risks, uncertainties and other factors that could cause actual results and experience to differ from those projected, including, but not limited to, the risk factors described herein and the risk factors set forth in Part I — Item 1A, “Risk Factors”, in our Annual Report on Form 10-K for the year ended December 31, 2022, as filed with the SEC on March 10, 2023, in our Quarterly Report on Form 10-Q for the quarter ended March 31, 2023, as filed with the SEC on May 12, 2023, in our Quarterly Report on Form 10-Q for the quarter ended June 30, 2023, as filed with the SEC on August 11, 2023, and in our Quarterly Report on Form 10-Q for the quarter ended September 30, 2023, as filed with the SEC on November 14, 2023, as updated by our subsequent annual, quarterly and other reports and documents that are incorporated by reference into this prospectus, and elsewhere in the documents incorporated by reference into this prospectus. Moreover, we operate in a very competitive and challenging environment. New risks and uncertainties emerge from time to time, and it is not possible for us to predict all risks and uncertainties that could have an impact on the forward-looking statements contained in this prospectus, the applicable prospectus supplement and any related free writing prospectus and in the documents incorporated by reference into this prospectus. We cannot assure you that the results, events and circumstances reflected in the forward-looking statements will be achieved or occur, and actual results, events or circumstances could differ materially from those described in the forward-looking statements.

The forward-looking statements made in this prospectus, the applicable prospectus supplement and any related free writing prospectus and in the documents incorporated by reference into this prospectus relate only to events as of the date on which the statements are made. We do not undertake any obligation to release publicly any revisions to such forward-looking statements to reflect events or circumstances after the date of this prospectus or to reflect new information or the occurrence of unanticipated events, except as required by law. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements and you should not place undue reliance on our forward-looking statements. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures, other strategic transactions or investments we may make or enter into.

TABLE OF CONTENTS

USE OF PROCEEDS

Except as otherwise provided in the applicable prospectus supplement or in any free writing prospectuses we have authorized for use in connection with a specific offering, we currently intend to use the net proceeds from the sale of the securities offered by this prospectus, if any, for working capital and general corporate purposes, which may include capital expenditures, research and development expenditures, regulatory affairs expenditures, clinical trial expenditures, acquisitions of new technologies and investments, business combinations and the repayment, refinancing, redemption or repurchase of indebtedness or capital stock.

The intended application of proceeds from the sale of any particular offering of securities using this prospectus will be described in the accompanying prospectus supplement relating to such offering. The precise amount and timing of the application of these proceeds will depend upon a number of factors, such as the timing and progress of our research and development efforts, our funding requirements and the availability and costs of other funds. Pending application of the net proceeds as described above, we intend to temporarily invest the proceeds in short-term, interest-bearing investment grant instruments, certificates of deposit or direct or guaranteed obligations of the U.S. government.

TABLE OF CONTENTS

DESCRIPTION OF CAPITAL STOCK

The following description of our capital stock is not complete and may not contain all the information you should consider before investing in our capital stock. This description is summarized from, and qualified in its entirety by reference to, our Amended and Restated Articles of Incorporation, as amended, which have been publicly filed with the SEC. See “Where You Can Find More Information.”

Our authorized capital stock consists of:

•

16,000,000 shares of common stock, $0.001 par value; and

•

10,000,000 shares of preferred stock, $0.001 par value.

Common Stock

Voting Rights. Holders of common stock are entitled to one vote per share for the election of directors and on all other matters that require stockholder approval. Holders of common stock do not have any cumulative voting rights.

Liquidation Rights. Subject to any preferential rights of any outstanding preferred stock, in the event of the Company’s liquidation, dissolution or winding up, holders of common stock are entitled to share ratably in the assets remaining after payment of liabilities and the liquidation preferences of any outstanding preferred stock.

No Preemptive or Redemption Rights. Shares of common stock do not carry any redemption rights or any preemptive or preferential rights enabling a holder to subscribe for, or receive shares of, any class of common stock or any other securities convertible into common stock.

Dividend Rights. Holders of common stock shall be entitled to receive dividends if, as and when declared by our board of directors in accordance with applicable law.

Anti-Takeover Provisions. See the below section titled “Anti-Takeover Effects of Nevada Law and Provisions of our Articles of Incorporation and Bylaws”.

Preferred Stock

We currently have no outstanding shares of preferred stock. Under our Amended and Restated Articles of Incorporation, as amended, our board of directors has the authority, without further action by stockholders, to designate one or more series of preferred stock and to fix the voting powers, designations, preferences, limitations, restrictions and relative rights granted to or imposed upon the preferred stock, including dividend rights, conversion rights, voting rights, rights and terms of redemption, liquidation preference and sinking fund terms. Any or all of these may be preferential to or greater than the rights of the common stock. Of our authorized preferred stock, 1,000,000 shares have been designated as Series A Junior Participating Preferred Stock, 800 shares have been designated as Series B 8% Cumulative Convertible Preferred Stock, and 600 shares have been designated as Series C 6% Cumulative Convertible Preferred Stock.

Our board of directors may authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of shares of common stock. The issuance of preferred stock, while providing flexibility in connection with possible acquisitions and other corporate purposes, could, among other things, have the effect of delaying, deferring or preventing a change in control of our company and may adversely affect the market price of the common stock and the voting and other rights of the holders of shares of common stock.

Our board of directors may specify the following characteristics of any preferred stock:

•

the designation and stated value, if any, of the class or series of preferred stock;

•

the number of shares of the class or series of preferred stock offered, and the liquidation preference, if any, per share;

TABLE OF CONTENTS

•

the dividend rate(s), period(s) or payment date(s) or method(s) of calculation, if any, applicable to the class or series of preferred stock;

•

whether dividends, if any, are cumulative or non-cumulative and, if cumulative, the date from which dividends on the class or series of preferred stock will accumulate;

•

the provisions for a sinking fund, if any, for the class or series of preferred stock;

•

the provision for redemption, if applicable, of the class or series of preferred stock;

•

the terms and conditions, if applicable, upon which the class or series of preferred stock will be convertible into common stock, including the conversion price or manner of calculation and conversion period;

•

voting rights, if any, of the class or series of preferred stock;

•

the relative ranking and preferences of the class or series of preferred stock as to dividend rights and rights, if any, upon the liquidation, dissolution or winding up of our affairs;

•

any limitations on issuance of any class or series of preferred stock ranking senior to or on a parity with the class or series of preferred stock as to dividend rights and rights, if any, upon liquidation, dissolution or winding up of our affairs; and

•

any other specific terms, preferences, rights, limitations or restrictions of the class or series of preferred stock.

Outstanding Warrants

As of December 15, 2023, we had outstanding warrants to purchase 5,280,357 shares of common stock as follows:

•

warrants to purchase an aggregate of 256 shares with an exercise price of $303.75 per share, all of which are currently exercisable (subject to certain beneficial ownership limitations) and expire on March 25, 2024, all of which shall be automatically exercised on a “cashless” basis upon expiration if the fair market value of the common stock is greater than the exercise price of the warrants on the expiration date of the warrants;

•

warrants to purchase an aggregate of 22 shares with an exercise price of $11,610.00 per share, all of which are currently exercisable and expire on October 17, 2024, all of which shall be automatically exercised on a “cashless” basis upon expiration if the fair market value of the common stock is greater than the exercise price of the warrants on the expiration date of the warrants;

•

warrants to purchase an aggregate of 17 shares with an exercise price of $14,760.00 per share, all of which are currently exercisable and expire on July 23, 2025, all of which shall be automatically exercised on a “cashless” basis upon expiration if the fair market value of the common stock is greater than the exercise price of the warrants on the expiration date of the warrants;

•

a warrant to purchase an aggregate of 3,834 shares with an exercise price of $270.00 per share, which is currently exercisable (subject to certain beneficial ownership limitations) and expires on March 25, 2024, which shall be automatically exercised on a “cashless” basis upon expiration if the fair market value of the common stock is greater than the exercise price of the warrants on the expiration date of the warrant;

•

a warrant to purchase an aggregate of 2,975 shares with an exercise price of $360.00 per share, which is currently exercisable and expires on March 25, 2024, which shall be automatically exercised on a “cashless” basis upon expiration if the fair market value of the common stock is greater than the exercise price of the warrants on the expiration date of the warrant;

•

Series A warrants to purchase an aggregate of 10,081 shares with an exercise price of $4.4705 per share, all of which are currently exercisable (subject to certain beneficial ownership limitations) and expire on January 31, 2024;

•

warrants to purchase an aggregate of 33,625 shares of common stock with an exercise price of $25.20 per share, all of which are currently exercisable (subject to certain beneficial ownership limitations) and expire on March 9, 2026;

TABLE OF CONTENTS

•

warrants to purchase an aggregate of 891,668 shares of common stock with an exercise price of $18.00 per share, all of which are currently exercisable (subject to certain beneficial ownership limitations) and expire on September 14, 2028;

•

warrants to purchase an aggregate of 133,335 shares of common stock with an exercise price of $31.80 per share, which become exercisable on November 19, 2023 and expire on November 19, 2028; and

•

warrants to purchase an aggregate of 4,204,546 shares of common stock with an exercise price of $1.32 per share, all of which are currently exercisable (subject to certain beneficial ownership limits) and expire on December 1, 2028.

All of the outstanding warrants contain provisions for the adjustment of the exercise price in the event of stock dividends, stock splits or similar transactions. In addition, certain of the warrants contain a “cashless exercise” feature that allows the holders thereof to exercise the warrants without a cash payment to us under certain circumstances. Certain of the warrants also contain provisions that provide certain rights to warrantholders in the event of a fundamental transaction, including a merger or consolidation with or into another entity, such as:

•

the right to receive the same amount and kind of consideration paid to the holders of common stock in the fundamental transaction;

•

the right to require us or a successor entity to purchase the unexercised portion of certain warrants at the warrant’s respective fair value using the Black Scholes option pricing formula; or

•

the right to require us or a successor entity to redeem the unexercised portion of certain warrants for the same consideration paid to holders of common stock in the fundamental transaction at the warrant’s respective fair value using the Black Scholes option pricing formula.

Convertible Promissory Note

As of December 15, 2023, we had one outstanding convertible promissory note (the “Note”) in an aggregate principal outstanding amount of approximately $13.9 million, which was issued on November 23, 2021, is convertible by the holder thereof into up to approximately 77,000 shares of common stock any time and matures on November 23, 2024.

The Note provides that, commencing on the nine-month anniversary of the date of issuance of the Note, the holder of the Note may convert any portion of the then-outstanding principal amount into shares of common stock at a price per share of $180.00, subject to adjustment for stock splits, reverse stock splits, stock dividends and similar transactions. Beginning on November 23, 2022, the Note began amortizing in twenty-four monthly installments equal to the quotient of (i) the then-outstanding principal amount of the Note, divided by (ii) the number of months remaining until the maturity date of the Note. All amortization payments shall be payable, at our sole option, in cash, shares of common stock or a combination of both. In addition, commencing on the last business day of the first month following November 23, 2022, we must pay, on a monthly basis, all interest that has accrued and remains unpaid on the then-outstanding principal amount of the Note. Any portion of an amortization payment or interest payment that is paid in shares of common stock shall be priced at 90% of the average of the five lowest daily volume weighted average prices of the common stock during the 20 trading days prior to the date of issuance of the shares.

Anti-Takeover Effects of Nevada Law and Provisions of our Articles of Incorporation and Bylaws

Certain provisions of Nevada law and our Amended and Restated Articles of Incorporation, as amended, and Amended and Restated Bylaws, as amended, could make the following more difficult:

•

acquisition of us by means of a tender offer;

•

acquisition of us by means of a proxy contest or otherwise; or

•

removal of our incumbent officers and directors.

These provisions, summarized below, could have the effect of discouraging certain types of coercive takeover practices and inadequate takeover bids. These provisions may also encourage persons seeking to acquire control of us to first negotiate with our board of directors.

TABLE OF CONTENTS

Classified Board. Our Amended and Restated Articles of Incorporation, as amended, provide that our board of directors is to be divided into three classes, as nearly equal in number as possible, with directors in each class serving three-year terms. This provision may have the effect of delaying or discouraging an acquisition of us or a change in our management.

Filling Vacancies. Our Amended and Restated Articles of Incorporation, as amended, provide that newly created directorships resulting from any increase in the authorized number of directors or any vacancies in the our board of directors resulting from death, resignation, retirement, disqualification, removal from office or other cause shall, unless otherwise provided by law or resolution of our board of directors, be filled only by a majority of the directors then in office, though less than a quorum. The directors so chosen shall hold office for a term expiring at the annual meeting of stockholders at which the term of office of the class to which they have been chosen expires.

Removal. The Nevada Revised Statutes (“NRS”) provide that any director may be removed from our board of directors by the vote or written consent of stockholders representing not less than two-thirds of the voting power of the issued and outstanding shares entitled to vote.

Requirements for Advance Notification of Stockholder Nominations and Proposals. Our Amended and Restated Bylaws, as amended, establish advance notice procedures with respect to stockholder proposals and the nomination of candidates for election as directors, other than nominations made by or at the direction of the board of directors.

Special Meetings of the Stockholders. Our Amended and Restated Bylaws, as amended, provide that special meetings of the stockholders may be called by our chair of our board of directors or our President, or by our board of directors acting pursuant to a resolution adopted by the total number of authorized directors, whether or not there exist any vacancies in previously authorized directorships.

No Cumulative Voting. Our Amended and Restated Articles of Incorporation, as amended, and Amended and Restated Bylaws, as amended, do not provide for cumulative voting in the election of directors.

Undesignated Preferred Stock. The authorization of undesignated preferred stock in our Amended and Restated Articles of Incorporation, as amended, makes it possible for our board of directors to issue preferred stock with voting or other rights or preferences that could impede the success of any attempt to change control of our company. These and other provisions may have the effect of deferring hostile takeovers or delaying changes in control or management of our company.

Amendment of Charter Provisions. The amendment of any of the above provisions set forth in our Amended and Restated Articles of Incorporation, as amended, except for the provision making it possible for our board of directors to issue undesignated preferred stock, would require approval by a stockholder vote by the holders of at least 662∕3% of the voting power of all the then-outstanding shares of our capital stock entitled to vote generally in the election of directors.

In addition, the NRS contain provisions governing the acquisition of a controlling interest in certain Nevada corporations. Nevada’s “acquisition of controlling interest” statutes (NRS 78.378 through 78.3793, inclusive) contain provisions governing the acquisition of a controlling interest in certain Nevada corporations. These “control share” laws provide generally that any person that acquires a “controlling interest” in certain Nevada corporations may be denied voting rights, unless a majority of the disinterested stockholders of the corporation elects to restore such voting rights. These laws will apply to us as of a particular date if we were to have 200 or more stockholders of record (at least 100 of whom have addresses in Nevada appearing on our stock ledger at all times during the 90 days immediately preceding that date) and do business in the State of Nevada directly or through an affiliated corporation, unless our articles of incorporation or bylaws in effect on the tenth day after the acquisition of a controlling interest provide otherwise. These laws provide that a person acquires a “controlling interest” whenever a person acquires shares of a subject corporation that, but for the application of these provisions of the NRS, would enable that person to exercise (1) one-fifth or more, but less than one-third, (2) one-third or more, but less than a majority or (3) a majority or more, of all of the voting power of the corporation in the election of directors. Once an acquirer crosses one of these thresholds, shares which it acquired in the transaction taking it over the threshold and within the 90 days immediately preceding the date when the acquiring person acquired or

TABLE OF CONTENTS

offered to acquire a controlling interest become “control shares” to which the voting restrictions described above apply. These laws may have a chilling effect on certain transactions if our Amended and Restated Articles of Incorporation, as amended, or Amended and Restated Bylaws, as amended, are not amended to provide that these provisions do not apply to us or to an acquisition of a controlling interest, or if our disinterested stockholders do not confer voting rights in the control shares.

Nevada’s “combinations with interested stockholders” statutes (NRS 78.411 through 78.444, inclusive) provide that specified types of business “combinations” between certain Nevada corporations and any person deemed to be an “interested stockholder” of the corporation are prohibited for two years after such person first becomes an “interested stockholder” unless the corporation’s board of directors approves the combination (or the transaction by which such person becomes an “interested stockholder”) in advance, or unless the combination is approved by the board of directors and sixty percent of the corporation’s voting power not beneficially owned by the interested stockholder, its affiliates and associates. Furthermore, in the absence of prior approval certain restrictions may apply even after such two-year period. For purposes of these statutes, an “interested stockholder” is any person who is (1) the beneficial owner, directly or indirectly, of 10% or more of the voting power of the outstanding voting shares of the corporation, or (2) an affiliate or associate of the corporation and at any time within the two previous years was the beneficial owner, directly or indirectly, of 10% or more of the voting power of the then-outstanding shares of the corporation. The definition of the term “combination” is sufficiently broad to cover most significant transactions between a corporation and an “interested stockholder”. These laws generally apply to Nevada corporations with 200 or more stockholders of record. However, a Nevada corporation may elect in its articles of incorporation not to be governed by these particular laws, but if such election is not made in the corporation’s original articles of incorporation, the amendment (1) must be approved by the affirmative vote of the holders of stock representing a majority of the outstanding voting power of the corporation not beneficially owned by interested stockholders or their affiliates and associates, and (2) is not effective until 18 months after the vote approving the amendment and does not apply to any combination with a person who first became an interested stockholder on or before the effective date of the amendment. We have not made such an election in our original articles of incorporation or in our Amended and Restated Articles of Incorporation, as amended, and we have not amended our Amended and Restated Articles of Incorporation to so elect.

Further, NRS 78.139 also provides that directors may resist a change or potential change in control of the corporation if the board of directors determines that the change or potential change is opposed to or not in the best interest of the corporation upon consideration of any relevant facts, circumstances, contingencies or constituencies pursuant to NRS 78.138(4).

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is EQ Shareowner Services. The transfer agent and registrar’s address is 1110 Centre Pointe Curve, Suite 101, Mendota Heights, MN 55120.

Listing

Our common stock is listed on the Nasdaq Capital Market under the symbol “SEEL”.

TABLE OF CONTENTS

DESCRIPTION OF DEBT SECURITIES

This prospectus describes the general terms and provisions of our debt securities. When we offer to sell a particular series of debt securities, we will describe the specific terms of the series in a supplement to this prospectus. We will also indicate in the supplement whether the general terms and provisions described in this prospectus apply to a particular series of debt securities. To the extent the information contained in the prospectus supplement differs from this summary description, you should rely on the information in the prospectus supplement.

Unless otherwise specified in a supplement to this prospectus, the debt securities will be our direct, unsecured obligations and will rank equally with all of our other unsecured and unsubordinated indebtedness. In the event that any series of debt securities will be subordinated to other indebtedness that we have outstanding or may incur, the terms of the subordination will be set forth in the prospectus supplement relating to the subordinated debt securities.

The debt securities will be issued under an indenture between Seelos and a trustee named in the prospectus supplement. We have summarized select portions of the indenture below. The summary is not complete. The form of the indenture has been filed as an exhibit to the registration statement and you should read the indenture for provisions that may be important to you. Capitalized terms used in the summary have the meaning specified in the indenture.

General

The terms of each series of debt securities will be established by or pursuant to a resolution of our board of directors and set forth or determined in the manner provided in a resolution of our board of directors, in an officer’s certificate or by a supplemental indenture. The particular terms of each series of debt securities will be described in a prospectus supplement relating to such series, including any pricing supplement or term sheet.

We can issue an unlimited amount of debt securities under the indenture that may be in one or more series with the same or various maturities, at par, at a premium, or at a discount. We will set forth in a prospectus supplement, including any pricing supplement or term sheet, relating to any series of debt securities being offered, the aggregate principal amount and the following terms of the debt securities, to the extent applicable:

•

the title of the debt securities;

•

the price or prices (expressed as a percentage of the principal amount) at which we will issue the debt securities;

•

any limit on the aggregate principal amount of the debt securities;

•

the date or dates on which we will pay the principal on the debt securities;

•

the form of the debt securities;

•

the rate or rates (which may be fixed or variable) per annum or the method used to determine the rate or rates (including any commodity, commodity index, stock exchange index or financial index) at which the debt securities will bear interest, the date or dates from which interest will accrue, the date or dates on which interest will commence and be payable and any regular record date for the interest payable on any interest payment date;

•

the place or places where principal of and interest on the debt securities will be payable;

•

the applicability of any guarantees;

•

the terms and conditions upon which we may redeem the debt securities;

•

whether and under what circumstances, if any, we will pay additional amounts on any debt securities held by a person who is not a United States person for tax purposes, and whether we can redeem the debt securities if we have to pay such additional amounts;

TABLE OF CONTENTS

•

any obligation we have to redeem or purchase the debt securities pursuant to any sinking fund or analogous provisions or at the option of a holder of debt securities;

•

the dates on which and the price or prices at which we will repurchase debt securities at the option of the holders of debt securities and other detailed terms and provisions of these repurchase obligations;

•

the denominations in which the debt securities will be issued, if other than denominations of $1,000 and any integral multiple thereof;

•

whether the debt securities will be issued in the form of certificated debt securities or global debt securities;

•

if the debt securities of the series will be issued in whole or in part in the form of a global debt security, the terms and conditions, if any, upon which such global debt security may be exchanged in whole or in part for other individual debt securities in definitive registered form, the depositary (as defined in the applicable prospectus supplement) for such global security and the form of any legend or legends to be borne by any such global security in addition to or in lieu of the legend referred to in the indenture;

•

the principal amount due at maturity, and whether the debt securities will be issued with original issue discount;

•

the portion of principal amount of the debt securities payable upon declaration of acceleration of the maturity date, if other than the principal amount;

•

the currency of denomination of the debt securities;

•

the designation of the currency, currencies or currency units in which payment of principal of and interest on the debt securities will be made;

•

if payments of principal of or interest on the debt securities will be made in one or more currencies or currency units other than that or those in which the debt securities are denominated, the manner in which the exchange rate with respect to these payments will be determined;

•

the manner in which the amounts of payment of principal of or interest on the debt securities will be determined, if these amounts may be determined by reference to an index based on a currency or currencies other than that in which the debt securities are denominated or designated to be payable or by reference to a commodity, commodity index, stock exchange index or financial index;

•

any provisions relating to any security provided for the debt securities;

•

the terms of the subordination of any series of the debt securities;

•

restrictions on transfer, sale or other assignment of the debt securities, if any;

•

if the principal amount payable at the stated maturity of debt securities of the series will not be determinable as of any one or more dates prior to such stated maturity, the amount that will be deemed to be such principal amount as of any such date for any purpose, including the principal amount thereof which will be due and payable upon any maturity other than the stated maturity or which will be deemed to be outstanding as of any such date (or, in any such case, the manner in which such deemed principal amount is to be determined), and if necessary, the manner of determining the equivalent thereof in U.S. dollars;

•

the right, if any, to extend the interest payment periods or defer the payment of interest and maximum length of any such deferral period;

•

with regard to the debt securities that do not bear interest, the dates for certain required reports to the trustee;

•

any provisions granting special rights to holders when a specified event occurs;

•

any addition to or change in the provisions relating to or dealing with defeasance;

•

any addition to or change in the events of default described in this prospectus or in the indenture with respect to the debt securities and any change in the acceleration provisions described in this prospectus or in the indenture with respect to the debt securities;

TABLE OF CONTENTS

•

any addition to or change in the covenants described in this prospectus or in the indenture with respect to the debt securities;

•

any other terms of the debt securities, which may supplement, modify or delete any provision of the indenture as it applies to that series; and

•

any depositaries, interest rate calculation agents, exchange rate calculation agents or other agents with respect to the debt securities.

In addition, the indenture does not limit our ability to issue convertible or subordinated debt securities. Any conversion or subordination provisions of a particular series of debt securities will be set forth in the resolution of our board of directors, the officer’s certificate or supplemental indenture related to that series of debt securities and will be described in the relevant prospectus supplement. Such terms may include provisions for conversion, either mandatory, at the option of the holder or at our option, in which case the number of shares of common stock or other securities to be received by the holders of debt securities would be calculated as of a time and in the manner stated in the prospectus supplement.

We may issue debt securities that provide for an amount less than their stated principal amount to be due and payable upon declaration of acceleration of their maturity pursuant to the terms of the indenture. We will provide you with information on the federal income tax considerations and other special considerations applicable to any of these debt securities in the applicable prospectus supplement.

If we denominate the purchase price of any of the debt securities in a foreign currency or currencies or a foreign currency unit or units, or if the principal of and interest on any series of debt securities is payable in a foreign currency or currencies or a foreign currency unit or units, we will provide you with information on the restrictions, elections, general tax considerations, specific terms and other information with respect to that issue of debt securities and such foreign currency or currencies or foreign currency unit or units in the applicable prospectus supplement.

Transfer and Exchange

Each debt security will be represented by either one or more global securities registered in the name of The Depository Trust Company, as depositary, or a nominee (we will refer to any debt security represented by a global debt security as a book-entry debt security), or a certificate issued in definitive registered form (we will refer to any debt security represented by a certificated security as a certificated debt security) as set forth in the applicable prospectus supplement. Except as set forth under the heading “— Global Debt Securities and Book-Entry System” below, book-entry debt securities will not be issuable in certificated form.

Certificated Debt Securities. You may transfer or exchange certificated debt securities at any office we maintain for this purpose in accordance with the terms of the indenture. No service charge will be made for any transfer or exchange of certificated debt securities, but we may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection with a transfer or exchange.

You may effect the transfer of certificated debt securities and the right to receive the principal of and interest on, certificated debt securities only by surrendering the certificate representing those certificated debt securities and either reissuance by us or the trustee of the certificate to the new holder or the issuance by us or the trustee of a new certificate to the new holder.

Global Debt Securities and Book-Entry System. Each global debt security representing book-entry debt securities will be deposited with, or on behalf of, the depositary, and registered in the name of the depositary or a nominee of the depositary.

We will require the depositary to agree to follow the following procedures with respect to book-entry debt securities.

Ownership of beneficial interests in book-entry debt securities will be limited to persons who have accounts with the depositary for the related global debt security, which we refer to as participants, or persons who may hold interests through participants. Upon the issuance of a global debt security, the depositary will credit, on its book-entry registration and transfer system, the participants’ accounts with the respective principal amounts of the book-entry debt securities represented by such global debt security

TABLE OF CONTENTS

beneficially owned by such participants. The accounts to be credited will be designated by any dealers, underwriters or agents participating in the distribution of the book-entry debt securities. Ownership of book-entry debt securities will be shown on, and the transfer of such ownership interests will be effected only through, records maintained by the depositary for the related global debt security (with respect to interests of participants) and on the records of participants (with respect to interests of persons holding through participants). The laws of some states may require that certain purchasers of securities take physical delivery of such securities in definitive form. These laws may impair the ability to own, transfer or pledge beneficial interests in book-entry debt securities.

So long as the depositary for a global debt security, or its nominee, is the registered owner of that global debt security, the depositary or its nominee, as the case may be, will be considered the sole owner or holder of the book-entry debt securities represented by such global debt security for all purposes under the indenture. Except as described below, beneficial owners of book-entry debt securities will not be entitled to have securities registered in their names, will not receive or be entitled to receive physical delivery of a certificate in definitive form representing securities and will not be considered the owners or holders of those securities under the indenture. Accordingly, each person beneficially owning book-entry debt securities must rely on the procedures of the depositary for the related global debt security and, if such person is not a participant, on the procedures of the participant through which such person owns its interest, to exercise any rights of a holder under the indenture.

We understand, however, that under existing industry practice, the depositary will authorize the persons on whose behalf it holds a global debt security to exercise certain rights of holders of debt securities, and the indenture provides that we, the trustee and our respective agents will treat as the holder of a debt security the persons specified in a written statement of the depositary with respect to that global debt security for purposes of obtaining any consents or directions required to be given by holders of the debt securities pursuant to the indenture.

We will make payments of principal of, and premium and interest on, book-entry debt securities to the depositary or its nominee, as the case may be, as the registered holder of the related global debt security. Seelos, the trustee and any other agent of ours or agent of the trustee will not have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in a global debt security or for maintaining, supervising or reviewing any records relating to beneficial ownership interests.

We expect that the depositary, upon receipt of any payment of principal of, and premium or interest on, a global debt security, will immediately credit participants’ accounts with payments in amounts proportionate to the respective amounts of book-entry debt securities held by each participant as shown on the records of such depositary. We also expect that payments by participants to owners of beneficial interests in book-entry debt securities held through those participants will be governed by standing customer instructions and customary practices, as is now the case with the securities held for the accounts of customers in bearer form or registered in “street name,” and will be the responsibility of those participants.

We will issue certificated debt securities in exchange for each global debt security if the depositary is at any time unwilling or unable to continue as depositary or ceases to be a clearing agency registered under the Exchange Act and a successor depositary registered as a clearing agency under the Exchange Act is not appointed by us within 90 days. In addition, we may at any time and in our sole discretion determine not to have the book-entry debt securities of any series represented by one or more global debt securities and, in that event, will issue certificated debt securities in exchange for the global debt securities of that series. Global debt securities will also be exchangeable by the holders for certificated debt securities if an event of default with respect to the book-entry debt securities represented by those global debt securities has occurred and is continuing. Any certificated debt securities issued in exchange for a global debt security will be registered in such name or names as the depositary shall instruct the trustee. We expect that such instructions will be based upon directions received by the depositary from participants with respect to ownership of book-entry debt securities relating to such global debt security.

We have obtained the foregoing information concerning the depositary and the depositary’s book-entry system from sources we believe to be reliable, but we take no responsibility for the accuracy of this information.

TABLE OF CONTENTS

No Protection in the Event of a Change of Control

Unless we state otherwise in the applicable prospectus supplement, the debt securities will not contain any provisions that may afford holders of the debt securities protection in the event we have a change in control or in the event of a highly leveraged transaction (whether or not such transaction results in a change in control) that could adversely affect holders of debt securities.

Covenants

We will set forth in the applicable prospectus supplement any restrictive covenants applicable to any issue of debt securities.

Subordination

Debt securities of a series may be subordinated, which we refer to as subordinated debt securities, to senior indebtedness (as defined in the applicable prospectus supplement) to the extent set forth in the prospectus supplement relating thereto. To the extent we conduct operations through subsidiaries, the holders of debt securities (whether or not subordinated debt securities) will be structurally subordinated to the creditors of our subsidiaries.

Consolidation, Merger or Sale of Assets

We may not consolidate with or merge with or into, or convey, transfer or lease all or substantially all of our properties and assets to, any person, which we refer to as a successor person, unless:

•

we are the surviving corporation or the successor person (if other than our Company) is a corporation organized and validly existing under the laws of any U.S. domestic jurisdiction and expressly assumes our obligations on the debt securities and under the indenture;

•

immediately after giving effect to the transaction, no event of default, and no event which, after notice or lapse of time, or both, would become an event of default, shall have occurred and be continuing under the indenture; and

•

certain other conditions are met.

Notwithstanding the above, any of our subsidiaries may consolidate with, merge into or transfer all or part of its properties to us.

Events of Default

Event of default means, with respect to any series of debt securities, any of the following:

•

default in the payment of any interest upon any debt security of that series when it becomes due and payable, and continuance of that default for a period of 30 days (unless the entire amount of the payment is deposited by us with the trustee or with a paying agent prior to the expiration of the 30-day period);

•

default in the payment of principal of any debt security of that series when due and payable;

•

default in the performance or breach of any other covenant or warranty by us in the indenture or any debt security (other than a covenant or warranty that has been included in the indenture solely for the benefit of a series of debt securities other than that series), which default continues uncured for a period of 60 days after we receive written notice from the trustee or we and the trustee receive written notice from the holders of not less than 25% in principal amount of the outstanding debt securities of that series as provided in the indenture;

•

certain events of bankruptcy, insolvency or reorganization of our company; and

•

any other event of default provided with respect to debt securities of that series that is described in the applicable prospectus supplement accompanying this prospectus.

No event of default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an event of default with respect to any

TABLE OF CONTENTS

other series of debt securities. The occurrence of certain events of default or an acceleration under the indenture may constitute an event of default under certain of our other indebtedness outstanding from time to time.

If an event of default with respect to debt securities of any series outstanding at the time occurs and is continuing, then the trustee or the holders of not less than 25% in principal amount of the outstanding debt securities of that series may, by a notice in writing to us (and to the trustee if given by the holders), declare to be due and payable immediately the principal (or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) of, and accrued and unpaid interest, if any, on all debt securities of that series. In the case of an event of default resulting from certain events of bankruptcy, insolvency or reorganization, the principal (or such specified amount) of and accrued and unpaid interest, if any, on all outstanding debt securities will become and be immediately due and payable without any declaration or other act on the part of the trustee or any holder of outstanding debt securities. At any time after a declaration of acceleration with respect to debt securities of any series has been made, but before a judgment or decree for payment of the money due has been obtained by the trustee, the holders of a majority in principal amount of the outstanding debt securities of that series may rescind and annul the acceleration if all events of default, other than the non-payment of accelerated principal and interest, if any, with respect to debt securities of that series, have been cured or waived as provided in the indenture. We refer you to the prospectus supplement relating to any series of debt securities that are discount securities for the particular provisions relating to acceleration of a portion of the principal amount of such discount securities upon the occurrence of an event of default.

The indenture provides that the trustee will be under no obligation to exercise any of its rights or powers under the indenture, unless the trustee receives indemnity satisfactory to it against any loss, liability or expense. Subject to certain rights of the trustee, the holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee or exercising any trust or power conferred on the trustee with respect to the debt securities of that series.

No holder of any debt security of any series will have any right to institute any proceeding, judicial or otherwise, with respect to the indenture or for the appointment of a receiver or trustee, or for any remedy under the indenture, unless:

•

that holder has previously given to the trustee written notice of a continuing event of default with respect to debt securities of that series; and

•

the holders of not less than 25% in principal amount of the outstanding debt securities of that series have made written request, and offered reasonable indemnity, to the trustee to institute the proceeding as trustee, and the trustee has not received from the holders of not less than 25% in principal amount of the outstanding debt securities of that series a direction inconsistent with that request and has failed to institute the proceeding within 60 days.

Notwithstanding the foregoing, the holder of any debt security will have an absolute and unconditional right to receive payment of the principal of and any interest on that debt security on or after the due dates expressed in that debt security and to institute suit for the enforcement of payment.

The indenture requires us, within 120 days after the end of our fiscal year, to furnish to the trustee a statement as to compliance with the indenture. The indenture provides that the trustee may withhold notice to the holders of debt securities of any series of any default or event of default (except in payment on any debt securities of that series) with respect to debt securities of that series if it in good faith determines that withholding notice is in the interest of the holders of those debt securities.

Modification and Waiver

We may modify and amend the indenture with the consent of the holders of at least a majority in principal amount of the outstanding debt securities of each series affected by the modifications or amendments. We may not make any modification or amendment without the consent of the holders of each affected debt security then outstanding if that amendment will:

TABLE OF CONTENTS

•

reduce the amount of debt securities whose holders must consent to an amendment, supplement or waiver;

•

reduce the rate of or extend the time for payment of interest (including default interest) on any debt security;

•

reduce the principal of or change the fixed maturity of any debt security or reduce the amount of, or postpone the date fixed for, the payment of any sinking fund or analogous obligation with respect to any series of debt securities;

•

reduce the principal amount of discount securities payable upon acceleration of maturity;

•

waive a default in the payment of the principal of or interest on any debt security (except a rescission of acceleration of the debt securities of any series by the holders of at least a majority in aggregate principal amount of the then outstanding debt securities of that series and a waiver of the payment default that resulted from such acceleration);

•

make the principal of or interest on any debt security payable in currency other than that stated in the debt security;

•

make any change to certain provisions of the indenture relating to, among other things, the right of holders of debt securities to receive payment of the principal of and interest on those debt securities and to institute a suit for the enforcement of any such payment and to waivers or amendments; or

•

waive a redemption payment with respect to any debt security.

Except for certain specified provisions, the holders of at least a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all debt securities of that series waive our compliance with provisions of the indenture. The holders of a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all the debt securities of such series waive any past default under the indenture with respect to that series and its consequences, except a default in the payment of the principal of or any interest on, any debt security of that series; provided, however, that the holders of a majority in principal amount of the outstanding debt securities of any series may rescind an acceleration and its consequences, including any related payment default that resulted from the acceleration.

Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

Legal Defeasance. The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, we may be discharged from any and all obligations in respect of the debt securities of any series (except for certain obligations to register the transfer or exchange of debt securities of such series, to replace stolen, lost or mutilated debt securities of such series, and to maintain paying agencies and certain provisions relating to the treatment of funds held by paying agents). We will be so discharged upon the deposit with the trustee, in trust, of money and/or U.S. government obligations or, in the case of debt securities denominated in a single currency other than U.S. dollars, foreign government obligations, that, through the payment of interest and principal in accordance with their terms, will provide money in an amount sufficient in the opinion of a nationally recognized firm of independent certified public accountants to pay and discharge each installment of principal and interest on and any mandatory sinking fund payments in respect of the debt securities of that series on the stated maturity of those payments in accordance with the terms of the indenture and those debt securities.

This discharge may occur only if, among other things, we have delivered to the trustee an opinion of counsel stating that we have received from, or there has been published by, the United States Internal Revenue Service a ruling or, since the date of execution of the indenture, there has been a change in the applicable United States federal income tax law, in either case to the effect that, and based thereon such opinion shall confirm that, the holders of the debt securities of that series will not recognize income, gain or loss for United States federal income tax purposes as a result of the deposit, defeasance and discharge and will be subject to United States federal income tax on the same amounts and in the same manner and at the same times as would have been the case if the deposit, defeasance and discharge had not occurred.

TABLE OF CONTENTS

Defeasance of Certain Covenants. The indenture provides that, unless otherwise provided by the terms of the applicable series of debt securities, upon compliance with certain conditions:

•

we may omit to comply with the covenant described under the heading “— Consolidation, Merger or Sale of Assets” and certain other covenants set forth in the indenture, as well as any additional covenants that may be set forth in the applicable prospectus supplement; and

•

any omission to comply with those covenants will not constitute a default or an event of default with respect to the debt securities of that series, or covenant defeasance.

The conditions include:

•

depositing with the trustee money and/or U.S. government obligations or, in the case of debt securities denominated in a single currency other than U.S. dollars, foreign government obligations, that, through the payment of interest and principal in accordance with their terms, will provide money in an amount sufficient in the opinion of a nationally recognized firm of independent certified public accountants to pay and discharge each installment of principal of and interest on and any mandatory sinking fund payments in respect of the debt securities of that series on the stated maturity of those payments in accordance with the terms of the indenture and those debt securities; and

•

delivering to the trustee an opinion of counsel to the effect that the holders of the debt securities of that series will not recognize income, gain or loss for United States federal income tax purposes as a result of the deposit and related covenant defeasance and will be subject to United States federal income tax on the same amounts and in the same manner and at the same times as would have been the case if the deposit and related covenant defeasance had not occurred.

Covenant Defeasance and Events of Default. In the event we exercise our option to effect covenant defeasance with respect to any series of debt securities and the debt securities of that series are declared due and payable because of the occurrence of any event of default, the amount of money and/or U.S. government obligations or foreign government obligations on deposit with the trustee will be sufficient to pay amounts due on the debt securities of that series at the time of their stated maturity but may not be sufficient to pay amounts due on the debt securities of that series at the time of the acceleration resulting from the event of default. In such a case, we would remain liable for those payments.

“Foreign Government Obligations” means, with respect to debt securities of any series that are denominated in a currency other than U.S. dollars:

•

direct obligations of the government that issued or caused to be issued such currency for the payment of which obligations its full faith and credit is pledged which are not callable or redeemable at the option of the issuer thereof; or

•

obligations of a person controlled or supervised by or acting as an agency or instrumentality of that government, the timely payment of which is unconditionally guaranteed as a full faith and credit obligation by that government which are not callable or redeemable at the option of the issuer thereof.

Regarding the Trustee

The indenture provides that, except during the continuance of an event of default, the trustee will perform only such duties as are specifically set forth in the indenture. During the existence of an event of default, the trustee will exercise such rights and powers vested in it under the indenture and use the same degree of care and skill in its exercise as a prudent person would exercise or use under the circumstances in the conduct of such person’s own affairs.

The indenture and provisions of the Trust Indenture Act of 1939, as amended, that are incorporated by reference therein contain limitations on the rights of the trustee, should it become one of our creditors, to obtain payment of claims in certain cases or to realize on certain property received by it in respect of any such claim as security or otherwise. The trustee is permitted to engage in other transactions with us or any of our affiliates; provided, however, that if it acquires any conflicting interest (as defined in the indentures or in the Trust Indenture Act of 1939, as amended), it must eliminate such conflict or resign.

TABLE OF CONTENTS

Regarding Payments and Paying Agents

Unless we state otherwise in the applicable prospectus supplement, we will make payment of the interest on any debt securities on any interest payment date to the person in whose name the debt securities are registered at the close of business on the regular record date for the interest payment.

We will pay principal of and any premium and interest on the debt securities of a particular series at the office of the paying agent designated by us, except that unless we indicate otherwise in the applicable prospectus supplement, we will make interest payments by check that we will mail to the holder or by wire transfer to certain holders. Unless we indicate otherwise in the applicable prospectus supplement, we will designate the corporate trust office of the debenture trustee as our sole paying agent for payments with respect to debt securities of each series. We will name in the applicable prospectus supplement any other paying agents that we initially designate for the debt securities of a particular series. We will maintain a paying agent in each place of payment for the debt securities of a particular series.

All money we pay to a paying agent or the trustee for the payment of the principal of or any premium or interest on any debt securities that remains unclaimed at the end of two years after such principal, premium or interest has become due and payable will be repaid to us, and the holder of the debt security thereafter may look only to us for payment thereof.

Governing Law

The indenture and the debt securities will be governed by, and construed in accordance with, the internal laws of the State of New York.

Convertible Promissory Note

As of December 15, 2023, we had one outstanding convertible promissory note (the “Note”) in an aggregate principal outstanding amount of $13.9 million, which was issued on November 23, 2021, is convertible by the holder thereof into up approximately 77,000 shares of common stock any time and matures on November 23, 2024.

The Note provides that, commencing on the nine-month anniversary of the date of issuance of the Note, the holder of the Note may convert any portion of the then-outstanding principal amount into shares of common stock at a price per share of $6.00, subject to adjustment for stock splits, reverse stock splits, stock dividends and similar transactions. Beginning on November 23, 2022, the Note began amortizing in twenty-four monthly installments equal to the quotient of (i) the then-outstanding principal amount of the Note, divided by (ii) the number of months remaining until the maturity date of the Note. All amortization payments shall be payable, at our sole option, in cash, shares of common stock or a combination of both. In addition, commencing on the last business day of the first month following November 23, 2022, we must pay, on a monthly basis, all interest that has accrued and remains unpaid on the then-outstanding principal amount of the Note. Any portion of an amortization payment or interest payment that is paid in shares of common stock shall be priced at 90% of the average of the five lowest daily volume weighted average prices of the common stock during the 20 trading days prior to the date of issuance of the shares.

TABLE OF CONTENTS

DESCRIPTION OF WARRANTS

The following description, together with the additional information we may include in the applicable prospectus supplements and free writing prospectuses we have authorized for use in connection with a specific offering, summarizes the material terms and provisions of the warrants that we may offer under this prospectus, which may consist of warrants to purchase common stock, preferred stock or debt securities and may be issued in one or more series.

Warrants may be issued independently or together with common stock, preferred stock or debt securities offered by any prospectus supplement, and may be attached to or separate from those securities. While the terms we have summarized below will apply generally to any warrants that we may offer under this prospectus, we will describe the particular terms of any series of warrants that we may offer in more detail in the applicable prospectus supplement and any applicable free writing prospectus we authorize for use in connection with the specific offering. The terms of any warrants offered under a prospectus supplement may differ from the terms described below.

We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of warrant agreement, if any, including a form of warrant certificate, that describes the terms of the particular series of warrants we are offering. The following summaries of material provisions of the warrants and the warrant agreements are subject to, and qualified in their entirety by reference to, all the provisions of the warrant agreement and warrant certificate applicable to the particular series of warrants that we may offer under this prospectus. We urge you to read the applicable prospectus supplements related to the particular series of warrants that we may offer under this prospectus, as well as any related free writing prospectuses we have authorized for use in connection with a specific offering, and the complete warrant agreements and warrant certificates that contain the terms of the warrants.

General Matters

We will describe in the applicable prospectus supplement the terms relating to a series of warrants being offered, including:

•

the title of such securities;

•

the offering price or prices and aggregate number of warrants offered;

•

the currency or currencies for which the warrants may be purchased;

•

if applicable, the designation and terms of the securities with which the warrants are issued and the number of warrants issued with each such security or each principal amount of such security;

•

if applicable, the date on and after which the warrants and the related securities will be separately transferable;

•

if applicable, the minimum or maximum amount of such warrants which may be exercised at any one time;

•

in the case of warrants to purchase debt securities, the principal amount of debt securities purchasable upon exercise of one warrant and the price at which, and currency in which, this principal amount of debt securities may be purchased upon such exercise;

•

in the case of warrants to purchase common stock or preferred stock, the number of shares of common stock or preferred stock, as the case may be, purchasable upon the exercise of one warrant and the price at which, and the currency in which, these shares may be purchased upon such exercise;

•

the effect of any merger, consolidation, sale or other disposition of our business on the warrant agreements and the warrants;

•

the terms of any rights to redeem or call the warrants;

•

the terms of any rights to force the exercise of the warrants;

•

any provisions for changes to or adjustments in the exercise price or number of securities issuable upon exercise of the warrants;

TABLE OF CONTENTS

•

the dates on which the right to exercise the warrants will commence and expire;

•

the manner in which the warrant agreements and warrants may be modified;

•

a discussion of any material or special United States federal income tax consequences of holding or exercising the warrants;

•

the terms of the securities issuable upon exercise of the warrants; and

•

any other specific terms, preferences, rights or limitations of or restrictions on the warrants.

Before exercising their warrants, holders of warrants will not have any of the rights of holders of the securities purchasable upon such exercise, including:

•

in the case of warrants to purchase debt securities, the right to receive payments of principal of, or premium, if any, or interest on, the debt securities purchasable upon exercise or to enforce covenants in the applicable indenture; or

•

in the case of warrants to purchase common stock or preferred stock, the right to receive dividends, if any, or, payments upon our liquidation, dissolution or winding up or to exercise voting rights, if any.

Exercise of Warrants

Each warrant will entitle the holder to purchase the securities that we specify in the applicable prospectus supplement at the exercise price that we describe in the applicable prospectus supplement. Unless we otherwise specify in the applicable prospectus supplement, holders of the warrants may exercise the warrants at any time up to the specified time on the expiration date that we set forth in the applicable prospectus supplement. After the close of business on the expiration date, unexercised warrants will become void.

Unless we otherwise specify in the applicable prospectus supplement, holders of the warrants may exercise the warrants by delivering the warrant certificate representing the warrants to be exercised together with specified information, and paying the required amount to the warrant agent in immediately available funds, as provided in the applicable prospectus supplement. We will set forth on the reverse side of the warrant certificate and in the applicable prospectus supplement the information that the holder of the warrant will be required to deliver to the warrant agent in connection with the exercise of the warrant.

Upon receipt of the required payment and the warrant certificate properly completed and duly executed at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement, we will issue and deliver the securities purchasable upon such exercise. If fewer than all of the warrants represented by the warrant certificate are exercised, then we will issue a new warrant certificate for the remaining amount of warrants. If we so indicate in the applicable prospectus supplement, holders of the warrants may surrender securities as all or part of the exercise price for warrants.

Governing Law

Unless we provide otherwise in the applicable prospectus supplement, the warrants and warrant agreements, and any claim, controversy or dispute arising under or related to the warrants or warrant agreements, will be governed by and construed in accordance with the laws of the State of New York.

Enforceability of Rights By Holders of Warrants

Each warrant agent will act solely as our agent under the applicable warrant agreement and will not assume any obligation or relationship of agency or trust with any holder of any warrant. A single bank or trust company may act as warrant agent for more than one issue of warrants. A warrant agent will have no duty or responsibility in case of any default by us under the applicable warrant agreement or warrant, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a warrant may, without the consent of the related warrant agent or the holder of any other warrant, enforce by appropriate legal action its right to exercise, and receive the securities purchasable upon exercise of, its warrants.

TABLE OF CONTENTS

Warrant Agreement Will Not Be Qualified Under Trust Indenture Act

No warrant agreement will be qualified as an indenture, and no warrant agent will be required to qualify as a trustee, under the Trust Indenture Act. Therefore, holders of warrants issued under a warrant agreement will not have the protection of the Trust Indenture Act with respect to their warrants.

Calculation Agent

Calculations relating to warrants may be made by a calculation agent, an institution that we appoint as our agent for this purpose. The prospectus supplement for a particular warrant will name the institution that we have appointed to act as the calculation agent for that warrant as of the original issue date for that warrant. We may appoint a different institution to serve as calculation agent from time to time after the original issue date without the consent or notification of the holders.

The calculation agent’s determination of any amount of money payable or securities deliverable with respect to a warrant will be final and binding in the absence of manifest error.

Outstanding Warrants

As of December 15, 2023, we had outstanding warrants to purchase 5,280,357 shares of common stock as follows:

•

TABLE OF CONTENTS

•

warrants to purchase an aggregate of 133,335 shares of common stock with an exercise price of $31.80 per share, which become exercisable on November 19, 2023 and expire on November 19, 2028; and

•

the right to receive the same amount and kind of consideration paid to the holders of common stock in the fundamental transaction;

•

the right to require us or a successor entity to purchase the unexercised portion of certain warrants at the warrant’s respective fair value using the Black Scholes option pricing formula; or

•

The Series A warrants provide that, if we publicly announce, issue or sell, or are deemed to have issued or sold any shares of our common stock for a price per share lower than the exercise price of the Series A warrants then in effect after January 31, 2022, subject to certain limited exceptions, then the exercise price of the Series A warrants shall be reduced to an amount equal to the product of (i) the exercise price in effect immediately prior to such public announcement, issue or sale or deemed issuance or sale and (ii) the quotient determined by dividing (a) the sum of (x) the product derived by multiplying the exercise price then in effect and the number of shares of our common stock outstanding immediately prior to the new issuance plus (y) the consideration received by us for the new issuance, by (b) the product derived by multiplying (x) the exercise price then in effect by (y) the number of shares of our common stock outstanding immediately after the new issuance. Shares of our common stock will be deemed to be issued or sold if we: (1) grant or sell, or publicly announce the issuance or sale of, any options to purchase shares of our common stock and the lowest price per share for which one share of common stock is issuable upon the exercise of such option (or upon conversion, exercise or exchange of any convertible security issuable upon exercise of such option) is less than the exercise price of the Series A warrant, or (2) issue or sell, or publicly announce the issuance or sale of, any convertible securities and the lowest price per share for which one share of our common stock is issuable upon the conversion, exercise or exchange of such convertible security is less than the exercise price of the Series A warrant. As of December 15, 2023, the exercise price of the Series A warrants was $4.4705 per share. The exercise price is subject to adjustment in accordance with the foregoing provisions and in the event of stock dividends, stock splits or similar transactions.

TABLE OF CONTENTS

DESCRIPTION OF UNITS

We may issue units consisting of any combination of the other types of securities offered under this prospectus in one or more series. We may evidence each series of units by unit certificates that we will issue under a separate agreement. We may enter into unit agreements with a unit agent. Each unit agent will be a bank or trust company that we select. We will indicate the name and address of the unit agent in the applicable prospectus supplement relating to a particular series of units.

The following description, together with the additional information included in the applicable prospectus supplement, summarizes the general features of the units that we may offer under this prospectus. You should read any prospectus supplement and any free writing prospectus we authorize for use in connection with a specific offering of units, as well as the complete unit agreements that contain the terms of the units. Specific unit agreements will contain additional important terms and provisions and we will file as an exhibit to the registration statement of which this prospectus is a part, or will incorporate by reference from another report that we file with the SEC, the form of each unit agreement relating to units offered under this prospectus.

If we offer any units, certain terms of that series of units will be described in the applicable prospectus supplement, including, without limitation, the following, as applicable:

•

the title of the series of units;

•

identification and description of the separate constituent securities comprising the units;

•

the price or prices at which the units will be issued;

•

the date, if any, on and after which the constituent securities comprising the units will be separately transferable;

•

a discussion of certain U.S. federal income tax considerations applicable to the units; and

•

any other terms of the units and their constituent securities.

TABLE OF CONTENTS

DESCRIPTION OF RIGHTS

We may issue rights to purchase common stock, preferred stock, debt securities, warrants, units and/or any of the other securities described in this prospectus. We may offer rights separately or together with one or more additional rights, preferred stock, common stock, debt securities, warrants, units or any combination of those securities in the form of units, as described in the applicable prospectus supplement. Each series of rights will be issued under a separate rights agreement to be entered into between us and a bank or trust company, as rights agent. This prospectus and any accompanying prospectus supplement will contain the material terms and conditions for each right. The accompanying prospectus supplement may add, update or change the terms and conditions of the rights as described in this prospectus.

We will describe in the applicable prospectus supplement the terms and conditions of the issue of rights being offered, the rights agreement relating to the rights and the rights certificates representing the rights, including, as applicable:

•

the title of the rights;

•

the date of determining the stockholders entitled to the rights distribution;

•

the title, aggregate number or amount of underlying securities purchasable upon exercise of the rights;

•

the exercise price;

•

the currencies in which the rights are being offered;

•

the aggregate number of rights issued;

•

whether the rights are transferable and the date, if any, on and after which the rights will be separately transferable;

•

the date on which the right to exercise the rights will commence and the date on which the right to exercise the rights will expire;

•

the method by which holders of rights will be entitled to exercise;

•

the conditions to the completion of the offering, if any;

•

the withdrawal, termination and cancellation rights, if any;

•

whether there are backstop or standby purchaser or purchases and the terms of their commitment, if any;

•

whether stockholders are entitled to oversubscription rights, if any; and

•

any other terms of the rights, including terms, procedures and limitations relating to the distribution, exchange and exercise of the rights, as applicable, including any provisions for modifying any of the terms of the rights.

Each right will entitle the holder of rights to purchase for cash the principal amount of shares of common stock, preferred stock, debt securities, warrants, units or other securities, as applicable, at the exercise price provided in the applicable prospectus supplement. Rights may be exercised at any time up to the close of business on the expiration date for the rights provided in the applicable prospectus supplement. After the close of business on the expiration date, all unexercised rights will be void.

Holders may exercise rights as described in the applicable prospectus supplement. Upon receipt of payment and the rights certificate properly completed and duly executed at the corporate trust office of the rights or subscription agent or any other office indicated in the prospectus supplement, we will, as soon as practicable, forward the shares of common stock, preferred stock, debt securities, warrants, units or other securities, as applicable, purchasable upon exercise of the rights. If less than all of the rights issued in any rights offering are exercised, we may offer any unsubscribed securities directly to persons other than stockholders, to or through agents, underwriters, brokers or dealers or through a combination of such methods, including pursuant to standby underwriting or other arrangements, as described in the applicable prospectus supplement.

The rights agent for any rights we offer will be set forth in the applicable prospectus supplement.

TABLE OF CONTENTS

LEGAL OWNERSHIP OF SECURITIES

We may issue securities in registered form or in the form of one or more global securities. We describe global securities in greater detail below. We refer to those persons who have securities registered in their own names on the books that we or any applicable trustee, depositary, warrant agent or other agent maintain for this purpose as the “holders” of those securities. These persons are the legal holders of the securities. We refer to those persons who, indirectly through others, own beneficial interests in securities that are not registered in their own names, as “indirect holders” of those securities. As we discuss below, indirect holders are not legal holders, and investors in securities issued in book-entry form or in street name will be indirect holders.

Book-Entry Holders

We may issue securities in book-entry form only, as we will specify in the applicable prospectus supplement. This means securities may be represented by one or more global securities registered in the name of a financial institution that holds them as depositary on behalf of other financial institutions that participate in the depositary’s book-entry system. These participating institutions, which are referred to as participants, in turn, hold beneficial interests in the securities on behalf of themselves or their customers.

Only the person in whose name a security is registered is recognized as the holder of that security. Securities issued in global form will be registered in the name of the depositary or its participants. Consequently, for securities issued in global form, we will recognize only the depositary as the holder of the securities, and we will make all payments on the securities to the depositary. The depositary passes along the payments it receives to its participants, which in turn pass the payments along to their customers who are the beneficial owners. The depositary and its participants do so under agreements they have made with one another or with their customers; they are not obligated to do so under the terms of the securities.

As a result, investors in a global security will not own securities directly. Instead, they will own beneficial interests in a global security, through a bank, broker or other financial institution that participates in the depositary’s book-entry system or holds an interest through a participant. As long as the securities are issued in global form, investors will be indirect holders, and not legal holders, of the securities.

Street Name Holders

We may terminate a global security in certain situations, as described under “— Special Situations When a Global Security Will Be Terminated”, or issue securities that are not issued in global form. In these cases, investors may choose to hold their securities in their own names or in “street name”. Securities held by an investor in street name would be registered in the name of a bank, broker or other financial institution that the investor chooses, and the investor would hold only a beneficial interest in those securities through an account he or she maintains at that institution.

For securities held in street name, we or any applicable trustee or depositary will recognize only the intermediary banks, brokers and other financial institutions in whose names the securities are registered as the holders of those securities, and we or any such trustee or depositary will make all payments on those securities to them. These institutions pass along the payments they receive to their customers who are the beneficial owners, but only because they agree to do so in their customer agreements or because they are legally required to do so. Investors who hold securities in street name will be indirect holders, not legal holders, of those securities.

Legal Holders

Our obligations, as well as the obligations of any applicable trustee, agent or third party employed by us or a trustee or any agents, run only to the legal holders of the securities. We do not have obligations to investors who hold beneficial interests in global securities, in street name or by any other indirect means. This will be the case whether an investor chooses to be an indirect holder of a security or has no choice because we are issuing the securities only in global form.

For example, once we make a payment or give a notice to the legal holder, we have no further responsibility for the payment or notice even if that legal holder is required, under agreements with its

TABLE OF CONTENTS

participants or customers or by law, to pass the payment or notice along to the indirect holders but does not do so. Similarly, we may want to obtain the approval of the holders to amend an indenture, to relieve us of the consequences of a default or of our obligation to comply with a particular provision of an indenture, or for other purposes. In such an event, we would seek approval only from the legal holders, and not the indirect holders, of the securities. Whether and how the legal holders contact the indirect holders is up to the legal holders.

When we refer to “you” in this prospectus, we mean those who invest in the securities being offered by this prospectus, whether they are the holders or only indirect holders of those securities. When we refer to “your securities” in this prospectus, we mean the securities in which you will hold a direct or indirect interest.

Special Considerations for Indirect Holders

If you hold securities through a bank, broker or other financial institution, either in book-entry form because the securities are represented by one or more global securities or in street name, you should check with your own institution to find out:

•

how it handles securities payments and notices;

•

whether it imposes fees or charges;

•

how it would handle a request for the holders’ consent, if ever required;

•

whether and how you can instruct it to send you securities registered in your own name so you can be a legal holder, if that is permitted in the future;

•

how it would exercise rights under the securities if there were a default or other event triggering the need for holders to act to protect their interests; and

•

if the securities are in book-entry form, how the depositary’s rules and procedures will affect these matters.

Global Securities

A global security is a security that represents one or any other number of individual securities held by a depositary. Generally, all securities represented by the same global securities will have the same terms.

Each security issued in book-entry form will be represented by a global security that we issue to, deposit with and register in the name of a financial institution or its nominee that we select. The financial institution that we select for this purpose is called the depositary. Unless we specify otherwise in the applicable prospectus supplement, The Depository Trust Company, New York, New York, known as DTC, will be the depositary for all securities issued in book-entry form.

A global security may not be transferred to or registered in the name of anyone other than the depositary, its nominee or a successor depositary, unless special termination situations arise. We describe those situations below under “— Special Situations When a Global Security Will Be Terminated”. As a result of these arrangements, the depositary, or its nominee, will be the sole registered owner and legal holder of all securities represented by a global security, and investors will be permitted to own only beneficial interests in a global security. Beneficial interests must be held by means of an account with a broker, bank or other financial institution that in turn has an account with the depositary or with another institution that does. Thus, an investor whose security is represented by a global security will not be a legal holder of the security, but only an indirect holder of a beneficial interest in the global security.

If the prospectus supplement for a particular security indicates that the security will be issued as a global security, then the security will be represented by a global security at all times unless and until the global security is terminated. If termination occurs, we may issue the securities through another book-entry clearing system or decide that the securities may no longer be held through any book-entry clearing system.

Special Considerations for Global Securities

The rights of an indirect holder relating to a global security will be governed by the account rules of the investor’s financial institution and of the depositary, as well as general laws relating to securities transfers.

TABLE OF CONTENTS

We do not recognize an indirect holder as a holder of securities and instead deal only with the depositary that holds the global security.

If securities are issued only in the form of a global security, an investor should be aware of the following:

•

an investor cannot cause the securities to be registered in his or her name, and cannot obtain non-global certificates for his or her interest in the securities, except in the special situations described below;

•

an investor will be an indirect holder and must look to his or her own bank or broker for payments on the securities and protection of his or her legal rights relating to the securities, as described above;

•

an investor may not be able to sell interests in the securities to some insurance companies and to other institutions that are required by law to own their securities in non-book-entry form;

•

an investor may not be able to pledge his or her interest in the global security in circumstances where certificates representing the securities must be delivered to the lender or other beneficiary of the pledge in order for the pledge to be effective;

•

the depositary’s policies, which may change from time to time, will govern payments, transfers, exchanges and other matters relating to an investor’s interest in the global security;

•

we and any applicable trustee have no responsibility for any aspect of the depositary’s actions or for its records of ownership interests in the global security, nor will we or any applicable trustee supervise the depositary in any way;

•

the depositary may, and we understand that DTC will, require that those who purchase and sell interests in the global security within its book-entry system use immediately available funds, and your broker or bank may require you to do the same; and

•

financial institutions that participate in the depositary’s book-entry system, and through which an investor holds its interest in the global security, may also have their own policies affecting payments, notices and other matters relating to the securities.

There may be more than one financial intermediary in the chain of ownership for an investor. We do not monitor and are not responsible for the actions of any of those intermediaries.

Special Situations When a Global Security Will Be Terminated

In a few special situations described below, a global security will terminate and interests in it will be exchanged for physical certificates representing those interests. After that exchange, the choice of whether to hold securities directly or in street name will be up to the investor. Investors must consult their own banks or brokers to find out how to have their interests in securities transferred to their own names, so that they will be direct holders. The rights of holders and street name investors are described above.

Unless we provide otherwise in the applicable prospectus supplement, a global security will terminate when the following special situations occur:

•

if the depositary notifies us that it is unwilling, unable or no longer qualified to continue as depositary for that global security and we do not appoint another institution to act as depositary within 90 days;

•

if we notify any applicable trustee that we wish to terminate that global security; or

•

if an event of default has occurred with regard to securities represented by that global security and has not been cured or waived.

The applicable prospectus supplement may also list additional situations for terminating a global security that would apply only to the particular series of securities covered by the prospectus supplement. When a global security is terminated, the depositary, and not we, the trustee, the agent or other third party, as applicable, is responsible for deciding the names of the institutions in whose names the securities represented by the global security will be registered and, therefore, who will be the direct holders of those securities.

TABLE OF CONTENTS

PLAN OF DISTRIBUTION

We may sell the securities from time to time pursuant to underwritten public offerings, direct sales to the public, “at the market” offerings, negotiated transactions, block trades or a combination of these methods. We may sell the securities to or through underwriters or dealers, through agents, directly to one or more purchasers or through any combination of the foregoing. We may distribute securities from time to time in one or more transactions:

•

at a fixed price or prices, which may be changed;

•

at market prices prevailing at the time of sale;

•

at prices related to such prevailing market prices; or

•

at negotiated prices.

In addition, we may issue the securities as a dividend or distribution to our existing securityholders.

A prospectus supplement or supplements (and any related free writing prospectus that we may have authorized for use in connection with a specific offering) will describe the terms of the offering of the securities, including, to the extent applicable:

•

the name or names of the agents, dealers or underwriters, if any;

•

the purchase price of the securities or other consideration therefor, and the proceeds, if any, we will receive from the sale;

•

any over-allotment options under which underwriters may purchase additional securities from us;

•

any agency fees or underwriting discounts and other items constituting agents’ or underwriters’ compensation;

•

any public offering price;

•

any discounts or concessions allowed or re-allowed or paid to dealers; and

•

any securities exchange or market on which the securities may be listed.

Only underwriters named in the prospectus supplement will be underwriters of the securities offered by the prospectus supplement.

If underwriters or agents are used in the sale of the securities in respect of which this prospectus is delivered, we will enter into an underwriting agreement or other agreement with them at the time of sale to them, and we will set forth in the prospectus supplement relating to such offering the names of the underwriters or agents and the terms of the related agreement with them.

We may directly solicit offers to purchase securities or agents may be designated to solicit such offers. We will, in the prospectus supplement relating to such offering, name any agent that could be viewed as an underwriter under the Securities Act and describe any commissions that we must pay. Any such agent will be acting on a best efforts basis for the period of its appointment or, if indicated in the applicable prospectus supplement, on a firm commitment basis. This prospectus may be used in connection with any offering of our securities through any of these methods or other methods described in the applicable prospectus supplement.

We may authorize agents or underwriters to solicit offers by certain types of institutional investors to purchase securities from us at the public offering price set forth in the prospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a specified date in the future. We will describe the conditions to these contracts and the commissions we must pay for solicitation of these contracts in the prospectus supplement.

If a dealer is utilized in the sale of the securities in respect of which the prospectus is delivered, we will sell such securities to the dealer, as principal. The dealer may then resell such securities to the public at varying prices to be determined by such dealer at the time of resale.

TABLE OF CONTENTS

We may provide agents and underwriters with indemnification against civil liabilities, including liabilities under the Securities Act, or contribution with respect to payments that the agents or underwriters may make with respect to these liabilities. Agents and underwriters may engage in transactions with, or perform services for, us in the ordinary course of business.

In order to facilitate the offering of the securities, any underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of the securities or any other securities the prices of which may be used to determine payments on such securities. Specifically, any underwriters may over-allot in connection with the offering, creating a short position for their own accounts. In addition, to cover over-allotments or to stabilize the price of the securities or of any such other securities, the underwriters may bid for, and purchase, the securities or any such other securities in the open market. Finally, in any offering of the securities through a syndicate of underwriters, the underwriting syndicate may reclaim selling concessions allowed to an underwriter or a dealer for distributing the securities in the offering if the syndicate repurchases previously distributed securities in transactions to cover syndicate short positions, in stabilization transactions or otherwise. Any of these activities may stabilize or maintain the market price of the securities above independent market levels. Any such underwriters are not required to engage in these activities and may end any of these activities at any time.

The securities may be new issues of securities and may have no established trading market. The securities may or may not be listed on a national securities exchange. We can make no assurance as to the liquidity of or the existence of trading markets for any of the securities.

The specific terms of any lock up provisions in respect of any given offering will be described in the applicable prospectus supplement.

TABLE OF CONTENTS

LEGAL MATTERS

The validity of the shares of common stock and preferred stock offered by this prospectus, and certain other matters of Nevada law, will be passed upon for us by Brownstein Hyatt Farber Schreck, LLP, Las Vegas, Nevada. Unless otherwise indicated in the applicable prospectus supplement, certain legal matters in connection with the offering and the enforceability of debt securities, warrants, units or rights offered by this prospectus, and any supplement thereto, will be passed upon for us by Paul Hastings LLP, Palo Alto, California.

EXPERTS

The consolidated financial statements of Seelos Therapeutics, Inc. as of December 31, 2022 and 2021, and for each of the years in the two-year period ended December 31, 2022, have been incorporated by reference herein in reliance upon the report of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing. The audit report covering the December 31, 2022 consolidated financial statements contains an explanatory paragraph that states that Seelos Therapeutics, Inc.’s recurring losses from operations and net capital deficiency raises substantial doubt about the entity’s ability to continue as a going concern. The financial statements do not include any adjustments that might result from the outcome of that uncertainty.

WHERE YOU CAN FIND MORE INFORMATION

We are a reporting company and file annual, quarterly and current reports, proxy statements and other information with the SEC. We have filed with the SEC a registration statement on Form S-3 under the Securities Act with respect to the securities being offered under this prospectus. This prospectus does not contain all of the information set forth in the registration statement and the exhibits to the registration statement. For further information with respect to us and the securities being offered under this prospectus, we refer you to the registration statement and the exhibits and schedules filed as a part of the registration statement. The SEC maintains an Internet site that contains reports, proxy and information statements, and other information regarding issuers that file electronically with the SEC, including Seelos Therapeutics, Inc. The SEC’s Internet site can be found at http://www.sec.gov.

TABLE OF CONTENTS

INCORPORATION OF DOCUMENTS BY REFERENCE

The SEC allows us to “incorporate by reference” information into this prospectus, which means that we can disclose important information to you by referring you to another document filed separately with the SEC. The documents incorporated by reference into this prospectus contain important information that you should read about us.

The following documents are incorporated by reference into this prospectus:

•

Our Annual Report on Form 10-K for the year ended December 31, 2022, as filed with the SEC on March 10, 2023;

•

Our Quarterly Report on Form 10-Q for the quarter ended March 31, 2023, as filed with the SEC on May 12, 2023;

•

Our Quarterly Report on Form 10-Q for the quarter ended June 30, 2023, as filed with the SEC on August 11, 2023;

•

Our Quarterly Report on Form 10-Q for the quarter ended September 30, 2023, as filed with the SEC on November 14, 2023;

•

The information specifically incorporated by reference into our Annual Report on Form 10-K for the fiscal year ended December 31, 2022 from our Definitive Proxy Statement on Schedule 14A, as filed with the SEC on April 12, 2023;

•

Our Current Reports on Form 8-K filed with the SEC on (i) March 14, 2023, (ii) March 24, 2023, (iii) May 19, 2023, (iv) May 26, 2023, (v) June 29, 2023, (vi) September 14, 2023, (vii) September 20, 2023, (viii) September 25, 2023, (ix) October 2, 2023, (x) November 3, 2023, (xi) November 28, 2023, (xii) November 30, 2023 and (xiii) December 1, 2023; and

•

The description of our common stock set forth in our Registration Statement on Form 8-A (File No. 000-22245), filed with the SEC on April 10, 2000, including any amendments or reports filed for the purpose of updating such description, including the description of our common stock included as Exhibit 4.12 to our Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on March 10, 2023.

We also incorporate by reference any future filings (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items unless such Form 8-K expressly provides to the contrary) made with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, including those made after the date of the initial filing of the registration statement of which this prospectus is a part and prior to effectiveness of such registration statement, until we file a post-effective amendment that indicates the termination of the offering of the securities made by this prospectus and such future filings and will become a part of this prospectus from the respective dates that such documents are filed with the SEC. Any statement contained herein or in a document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes hereof or of the related prospectus supplement to the extent that a statement contained herein or in any other subsequently filed document which is also incorporated or deemed to be incorporated by reference herein modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus.

You may obtain any of the documents incorporated by reference in this prospectus from the SEC through the SEC’s website at the address provided above. Documents incorporated by reference are also available from us, without charge. You may obtain documents incorporated by reference in this prospectus by requesting them in writing or by telephone at the following address or phone number:

Seelos Therapeutics, Inc.
300 Park Avenue, 2nd Floor
New York, New York 10022
Attn: Corporate Secretary
Phone: (646) 293-2100

TABLE OF CONTENTS

380,968 Shares of Common Stock

Pre-Funded Warrants to Purchase 81,239 Shares of Common Stock

Up to 81,239 Shares of Common Stock Underlying the Pre-Funded Warrants

PROSPECTUS SUPPLEMENT

Roth Capital Partners

May 16, 2024

Market Data

News

Trading Tools

Markets

Discover

Hot Features

Follow Feed

Options Flow

Monitor

SEEL Seelos Therapeutics Inc