Atreca Announces Oral Presentation of ATRC-101 Phase 1b Study Data at ASCO 2023 Annual Meeting

Atreca, Inc. (Atreca) (NASDAQ: BCEL), a clinical-stage biotechnology company focused on developing novel cancer therapeutics generated through a unique discovery platform based on interrogation of the active human immune response, today announced that data from the Phase 1b study of ATRC-101 will be presented during an oral abstract session at the American Society of Clinical Oncology 2023 Annual Meeting, being held June 2-6, 2023 in Chicago, Illinois.

Details of the presentation are as follows:

Abstract Title: Interim update of the ATRC-101 phase 1b trial in advanced solid tumors.Abstract Number: 2505Session: Developmental Therapeutics - ImmunotherapyDate / Time: June 4, 2023; 9:45am – 12:45pm CDTPresenting Author: Dr. Bartosz Chmielowski, Health Sciences Clinical Professor of Medicine, Division of Hematology-Oncology, University of California Los Angeles

About Atreca, Inc.Atreca is a biopharmaceutical company developing novel antibody-based therapeutics generated by its differentiated discovery platform. Atreca's platform allows access to an unexplored landscape in oncology through the identification of unique antibody-target pairs generated by the human immune system during an active immune response against tumors. These antibodies provide the basis for first-in-class therapeutic candidates, such as our lead product candidate ATRC-101. A Phase 1b study evaluating ATRC-101 in multiple solid tumor cancers is currently enrolling patients. For more information on Atreca, please visit www.atreca.com.

Forward-Looking StatementsThis release contains statements regarding matters that are not historical facts that are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements include, but are not limited to, statements regarding our strategy and future plans, including statements regarding the development of ATRC-101, and our preclinical and clinical plans and the timing thereof. Our actual results may differ materially from those indicated in these forward-looking statements due to risks and uncertainties related to the initiation, timing, progress and results of our research and development programs, preclinical studies, clinical trials, regulatory submissions, and other matters that are described in our most recent Annual Report on Form 10-K and Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) and available on the SEC's website at www.sec.gov, including the risk factors set forth therein. Investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this release, and we undertake no obligation to update any forward-looking statement in this press release, except as required by law.

Contacts

Atreca, Inc.Herb CrossChief Financial [e-mail]

Investors:Alex Gray, [e-mail]

Media:Julia Fuller, [e-mail]