Poseida Therapeutics to Present New Clinical Data from Phase 1 Study of Allogeneic CAR-T P-BCMA-ALLO1 in Patients with Relapsed/Refractory Multiple Myeloma at 21st International Myeloma Society Annual Meeting

Latest data from Poseida's lead investigational allogeneic CAR-T program, which is based on the Company's unique stem cell memory T cell (T_SCM) platform

Company to host conference call on Saturday, September 28, 2024, at 1 PM ET / 10 AM PT to review the P-BCMA-ALLO1 Phase 1 IMS oral presentation data

Poseida initiates P-BCMA-ALLO1 Phase 1b clinical trial in patients with multiple myeloma, generating $20 million payment from Roche

SAN DIEGO, Sept. 5, 2024 /PRNewswire/ -- Poseida Therapeutics, Inc. (Nasdaq: PSTX), a clinical-stage allogeneic cell therapy and genetic medicines company advancing differentiated non-viral treatments for patients with cancer and rare diseases, announced today that new clinical data from an ongoing Phase 1 study of P-BCMA-ALLO1 in patients with relapsed/refractory multiple myeloma will be presented in an oral session at the 21^st International Myeloma Society (IMS) Annual Meeting, which is being held in Rio de Janeiro from September 25-28, 2024. The Company is developing P-BCMA-ALLO1, an investigational off-the-shelf allogeneic CAR-T cell therapy enriched for stem cell memory T cells (T_SCM), in partnership with Roche for the treatment of relapsed/refractory multiple myeloma.

"Despite therapeutic advances, multiple myeloma remains an incurable hematologic cancer and relapses are common with BCMA-targeting immunotherapies, such as bispecific T-cell engagers and autologous CAR-T therapies. As a result, patient-focused, off-the-shelf therapies are needed that can provide clinical benefit to patients with relapsed or refractory disease," said Syed Rizvi, M.D., Chief Medical Officer of Poseida Therapeutics. "We look forward to presenting the latest data from our ongoing Phase 1 study of P-BCMA-ALLO1 and its potential as an 'off-the-shelf' therapy for patients at IMS. We are also pleased to announce the initiation of the Phase 1b portion of the study, which will allow us to further explore the promise of this program."

IMS Oral Presentation

• Talk Title: OA – 04: A Phase 1 Study of P-BCMA-ALLO1, a Non-viral, Allogeneic BCMA Directed CAR-T in Relapsed/Refractory Multiple Myeloma (RRMM)
• Presenting Author: Bhagirathbhai R. Dholaria, MBBS, Assistant Professor of Medicine, Department of Medicine, Division of Hematology and Oncology, Vanderbilt University Medical Center
• Session: Abstract Session 7
• Presentation Date/Time: Friday, September 27, 2024, at 5:42 PM-5:54 PM local time (4:42 PM ET / 1:42 PM PT)
• Room: 101 A1-A2

Company-Hosted IMS Webcast and Conference Call Information:
Poseida will host a webcast and conference call on Saturday, September 28, 2024, at 1 PM ET / 10 AM PT. The conference call can be accessed by dialing 800-225-9448 or 203-518-9708 (International) with the conference ID PSTX0928. A live webcast may be accessed using the link here, or by visiting the Events and Presentations section of the Poseida website at investors.poseida.com. After the live webcast, the event will remain archived on the Poseida site for approximately 90 days.

P-BCMA-ALLO1 Phase 1b Clinical Trial
The Company also announced the initiation of a Phase 1b portion of the ongoing Phase 1 clinical trial of P-BCMA-ALLO1 in patients with multiple myeloma. As a result of achieving this milestone, Poseida will receive a $20 million payment from Roche. Poseida and Roche partnered together on the P-BCMA-ALLO1 Phase 1b trial design, which incorporates process improvements and feedback from recently completed advisory board meetings with leading clinicians. Poseida will continue to have responsibility for the expanded Phase 1/1b trial, which will be funded by Roche.

About P-BCMA-ALLO1
P-BCMA-ALLO1 is an allogeneic CAR-T product candidate licensed to Roche targeting B-cell maturation antigen (BCMA) for the treatment of relapsed/refractory multiple myeloma. This allogeneic program includes a VH-based binder that targets BCMA and clinical data presented at ASH in December 2023 support the Company's belief that T stem cell (T_SCM)-rich allogeneic CAR-Ts have the potential to offer effective, safe, and reliable treatment addressing unmet needs in multiple myeloma. Additional information about the Phase 1 study is available at www.clinicaltrials.gov using identifier: NCT04960579.

About Poseida Therapeutics, Inc.
Poseida Therapeutics is a clinical-stage biopharmaceutical company advancing differentiated allogeneic cell therapies and genetic medicines with the capacity to cure certain cancers and rare diseases. The Company's pipeline includes investigational allogeneic CAR-T cell therapies for both solid tumors and hematologic cancers as well as investigational in vivo genetic medicines that address patient populations with high unmet medical need. The Company's approach is based on its proprietary genetic editing platforms, including its non-viral piggyBac® DNA Delivery System, Cas-CLOVER™ Site-Specific Gene Editing System, Booster Molecule and nanoparticle gene delivery technologies, as well as in-house GMP cell therapy manufacturing. The Company has formed strategic collaborations with Roche and Astellas to unlock the promise of cell therapies for cancer patients. Learn more at www.poseida.com and connect with Poseida on X and LinkedIn.

Forward-Looking Statements 
Statements contained in this press release regarding matters that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements include statements regarding, among other things, expected plans with respect to clinical trials, including timing of regulatory and submissions and approvals and clinical data updates; potential fees, reimbursements, milestones, royalty payments and other payments that the Company may receive pursuant to its collaboration agreements with Roche; anticipated timelines and milestones with respect to the Company's development programs and manufacturing activities and capabilities; the potential capabilities and benefits of the Company's technology platforms and product candidates, including the efficacy, safety and tolerability profile of such product candidates; the quote from Dr. Rizvi; and the Company's plans and strategy with respect to developing its technologies and product candidates. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. These forward-looking statements are based upon the Company's current expectations and involve assumptions that may never materialize or may prove to be incorrect. Actual results could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties, which include, without limitation, the Company's reliance on third parties for various aspects of its business; risks and uncertainties associated with development and regulatory approval of novel product candidates in the biopharmaceutical industry; the Company's ability to retain key scientific or management personnel; the fact that interim data from the Company's clinical trials may change as more patient data become available and remain subject to audit and verification procedures that could result in material differences from the final data; the fact that subgroup data may differ from future results of the same study once additional data has been received; and the other risks described in the Company's filings with the Securities and Exchange Commission. All forward-looking statements contained in this press release speak only as of the date on which they were made. The Company undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made, except as required by law.

SOURCE Poseida Therapeutics, Inc.