This Amendment No. 3 to Schedule TO (together with any exhibits and annexes attached hereto, and as it may be amended or supplemented from time to time, this “Amendment”) is filed by (i) Fennec Acquisition Incorporated, a Delaware corporation (“Purchaser”) and a direct wholly-owned subsidiary of invoX Pharma Limited, a private limited company organized under the laws of England and Wales (“Parent”), which is a direct wholly-owned subsidiary of Sino Biopharmaceutical Limited, a company organized under the laws of the Cayman Islands (“SBP”), (ii) Parent and (iii) SBP, and amends and supplements the Tender Offer Statement on Schedule TO filed with the U.S. Securities and Exchange Commission (the “SEC”) on July 7, 2022 (together with any amendments and supplements thereto, the “Schedule TO”) by Purchaser, Parent, and SBP. The Schedule TO relates to the offer by Purchaser to purchase all of the issued and outstanding shares (each, a “Share” and collectively, the “Shares”) of common stock, par value $0.0001 per share, of F-star Therapeutics, Inc., a Delaware corporation (the “Company”), for $7.12 per Share, payable net to the holder in cash, without interest, subject to any withholding taxes required by applicable law, and on the terms and subject to the conditions set forth in the Offer to Purchase, dated July 7, 2022 (the “Offer to Purchase”), a copy of which is attached as Exhibit (a)(1)(a) to the Schedule TO, and in the accompanying letter of transmittal, a copy of which is attached as Exhibit (a)(1)(b) to the Schedule TO, and which, as each may be amended or supplemented from time to time, collectively constitute the “Offer.”

Except as otherwise set forth in this Amendment, the information set forth in the Schedule TO remains unchanged and is incorporated herein by reference to the extent relevant to the items in this Amendment. Capitalized terms used but not defined herein have the meanings ascribed to them in the Schedule TO.

Items 1 through 9; Item 11.

The Offer to Purchase and Items 1 through 9 and Item 11 of the Schedule TO, to the extent such Items 1 through 9 and Item 11 incorporate by reference the information contained in the Offer to Purchase, are hereby amended and supplemented by adding the following paragraphs thereto:

On August 4, 2022, Purchaser, Parent, and SBP extended the Offer to 05:00 p.m., Eastern Time, on September 19, 2022, unless further extended. The Offer was previously set to expire at one (1) minute past 11:59 p.m., Eastern Time, on August 3, 2022. The Depositary has advised Purchaser, Parent, and SBP that, as of 11:59 p.m., Eastern Time, on August 3, 2022, 13,026,582 Shares had been tendered pursuant to the Offer, and approximately 2,704,867 Shares tendered pursuant to a notice of guaranteed delivery.

On August 4, 2022, Parent, SBP and the Company announced an extension of the Expiration Date of the Offer to 05:00 p.m., Eastern Time, on September 19, 2022, unless further extended.

The full text of the announcement of the extension is attached as Exhibit (a)(5)(d) to the Schedule TO and is incorporated herein by reference.

Item 11. Additional Information.

The Offer to Purchase and Item 11 of the Schedule TO, to the extent such Item 11 incorporates by reference the information contained in the Offer to Purchase, are hereby amended and supplemented as follows:

The last four paragraphs of Section 16 — “Certain Legal Matters; Regulatory Approvals” of the Offer to Purchase are hereby amended and restated in their entirety to read as follows (new language bolded and underlined; deleted language struck through):

Certain Litigation

On July 12, July 18, July 20, and July 22, 2022, four purported stockholders of the Company filed separate lawsuits against the Company and certain of its current and former directors and officers in the federal district court for the Southern District of New York, captioned Mark Diebolt v. F-star Therapeutics, Inc., et al., Case No. 1:22-cv-05941 (the “Diebolt Complaint”), Amber Johnson v. F-star Therapeutics, Inc., et al., Case No. 1:22-cv-06103 (the “Johnson Complaint”), Jacob Wheeler v. F-star Therapeutics, Inc., et al., Case No. 1:22-cv-00950 (the “Wheeler Complaint”), and Sam Carlisle v. F-star Therapeutics, Inc., et al., Case No. 1:22-cv-06253 (the “Carlisle Complaint,” and together with the Diebolt Complaint, Johnson Complaint, and Wheeler Complaint, the “Complaints”), respectively. Each complaint alleges violations of Sections 14(d) and 14(e) of the Exchange Act, and Rule 14d-9 promulgated thereunder and Section 20(a) of the Exchange Act. Each lawsuit alleges that the Schedule 14D-9 filed by the Company on July 7, 2022 is materially incomplete and misleading and seeks to enjoin the Offer until the purported deficiencies in the 14D-9 are corrected, or alternatively, seeks monetary damages if the Offer is consummated. The plaintiffs also seek fees and costs incurred in bringing the Complaints. The defendants believe the claims asserted in the Complaints are without merit.

The Company has also received demand letters from seveneight purported shareholders (collectively, the “Demand Letters”) separately (collectively, the “Demand Letters”) requesting that the Company provide additional disclosures in connection with the Merger.

The Company and the defendants named in the Complaints and the Demand Letters believe that the claims asserted in the Complaints and the Demand Letters are without merit.

Additional lawsuits arising out of or relating to the Offer may be filed and other demand letters may be received in the future. If additional similar complaints are filed or demand letters are received, absent new or different allegations that are material, the Company will not necessarily announce such additional filings.

Amendments to the Offer to Purchase and the Other Exhibits to the Schedule TO.

Exhibits (a)(1)(a) through (a)(1)(e) to the Schedule TO (and Items 1 through 9 and Item 11 of the Schedule TO, to the extent such Items 1 through 9 and Item 11 incorporate by reference the information contained in such Exhibits (a)(1)(a) through (a)(1)(e)) are hereby amended and supplemented as follows:

All references regarding the scheduled expiration of the Offer being “one (1) minute past 11:59 p.m., Eastern Time, on August 3, 2022” set forth in the Offer to Purchase, the Letter of Transmittal, Notice of Guaranteed Delivery, Letter to Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees, and Letter to Clients for Use by Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees are hereby amended and replaced with “05:00 p.m., Eastern Time, on September 19, 2022”.

Item 12. Exhibits.

Item 12 of the Schedule TO is hereby amended and supplemented to add the following exhibit(s):

SIGNATURE

After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: August 4, 2022

EXHIBIT INDEX