Poseida Therapeutics to Present Clinical and Preclinical Data on Investigational Allogeneic CAR-T Cell Therapies at SITC 2024 and ASH 2024

New preclinical data on allogeneic CAR+TCR-T cells rich in stem cell memory T cells (T_SCM) and enhanced potency to better target solid tumors will be presented at SITC

Additional profiling of patient responses in P-BCMA-ALLO1 Phase 1 Arm C and preclinical P-CD19CD20-ALLO1 to be presented at ASH

SAN DIEGO, Nov. 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, autoimmune and rare diseases, today announced new preclinical data on allogeneic CAR+TCR-T cells rich in stem cell memory T cells (T_SCM), along with platform enhancements aimed at enhancing potency and improving targeting of solid tumors, will be presented at the Society for Immunotherapy of Cancer (SITC) 39^th Annual Meeting in Houston, November 6-10.

Additionally, the Company announced presentations at the 66^th American Society of Hematology (ASH) Annual Meeting & Exposition, which will be held December 7-10 in San Diego. To further characterize compelling emerging P-BCMA-ALLO1 clinical data, additional profiling of patient responses from the optimized lymphodepletion arm (Arm C) of the P-BCMA-ALLO1 Phase 1 study, along with data first presented at the 21st International Myeloma Society (IMS) Annual Meeting will be highlighted as a poster presentation. In addition, preclinical data from the ongoing Phase 1 trial of P-CD19CD20-ALLO1 in patients with B-cell malignancies will be delivered as a poster presentation.

P-BCMA-ALLO1 is an investigational non-viral T_SCM-rich allogeneic CAR-T therapy in Phase 1/1b clinical development. This investigational off-the-shelf allogeneic CAR-T cell therapy targeting BCMA has received Regenerative Medicine Advanced Therapy (RMAT) designation for adult patients with relapsed/refractory multiple myeloma after three or more prior lines of therapies. P-CD19CD20-ALLO1, the Company's first allogeneic dual CAR-T cell product candidate, targets both CD19 and CD20 antigens for the treatment of relapsed or refractory B-cell malignancies. The Company is developing P-BCMA-ALLO1 and P-CD19CD20-ALLO1 as part of a broader collaboration with Roche focused on addressing hematologic malignancies with Poseida's T_SCM-rich CAR-T platform.

SITC 2024 Poster Presentation

Title: Multi-antigen Targeting with CAR and TCR Co-expression in Allogeneic Cell Therapy for Solid Tumors

• Presenting Author: Sergio M. Quinones-Parra, Ph.D., Poseida Therapeutics
• Presentation Date/Time: Saturday, November 9, 2024, at 8:00 a.m. CT (9:00 a.m. ET / 6:00 a.m. PT)
• Room: Exhibit Halls A and B, George R. Brown Convention Center
• Abstract Number: 301

ASH 2024 Poster Presentations

Title: Late Polyclonal P-BCMA-101 CAR-T Cell Re-expansion and Rapid Complete Response in a Patient with Relapsed Multiple Myeloma Treated with One Cycle of Talquetamab, More Than 3 Years After CAR-T Infusion

• Presenting Author: Anupama Kumar, M.D., Assistant Professor, Hematology, Blood & Marrow Transplant, and Cellular Therapy (HBC) Program, University of California, San Francisco (UCSF)
• Session: 704. Cellular Immunotherapies: Early Phase Clinical Trials and Toxicities: Poster I
• Presentation Date/Time: Saturday, December 7, 2024, 5:30-7:30 p.m. PT (8:30-10:30 p.m. ET)
• Room: Halls G-H, San Diego Convention Center
• Abstract Number: 2083

Title: P-CD19CD20-ALLO1: Potent Fully Allogeneic CAR-T Therapy Targeting CD19 and CD20 with Superior Efficacy Over Single-Target Products

• Presenting Author:  Samy Jambon, Ph.D., Poseida Therapeutics
• Session: 702. CAR-T Cell Therapies: Basic and Translational: Poster III
• Presentation Date/Time: Monday, December 9, 2024, 6:00-8:00 p.m. PT (9:00-11:00 p.m. ET)
• Room: Halls G-H, San Diego Convention Center
• Abstract Number: 4805

Title: A Phase 1 Study of P-BCMA-ALLO1, a Non-viral, Allogeneic BCMA Directed CAR-T in Relapsed/Refractory Multiple Myeloma (RRMM): Results from Optimized Lymphodepletion Cohort

• Presenting Author: Caitlin Costello, M.D., Professor of Medicine, Director of Multiple Myeloma Program, Division of Blood and Marrow Transplant, Moores Cancer Center, University of California, San Diego (UCSD)
• Session: 704. Cellular Immunotherapies: Early Phase Clinical Trials and Toxicities: Poster III
• Presentation Date/Time: Monday, December 9, 2024, 6:00-8:00 p.m. PT (9:00-11:00 p.m. ET)
• Room: Halls G-H, San Diego Convention Center
• Abstract Number: 4828

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 interim clinical data presented at IMS in September 2024 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. The U.S. Food and Drug Administration (FDA) has granted P-BCMA-ALLO1 Orphan Drug designation for multiple myeloma and Regenerative Medicine Advanced Therapy (RMAT) designation for adult patients with relapsed/refractory multiple myeloma after three or more prior lines of therapies including a proteasome inhibitor, an immunomodulatory agent and an anti-CD38 antibody.

P-BCMA-ALLO1 is currently being evaluated in a Phase 1/1b trial in patients with multiple myeloma. Additional information about the trial is available at www.clinicaltrials.gov using identifier: NCT04960579.

About P-CD19CD20-ALLO1
P-CD19CD20-ALLO1 is an allogeneic CAR-T cell therapy product candidate being developed for relapsed or refractory B-cell malignancies in partnership with Roche. P-CD19CD20-ALLO1 expresses two fully functional CAR molecules to target cells that express either CD19 or CD20. The dual targeting approach employed in P-CD19CD20-ALLO1 aims to overcome the antigen escape limitations of CD19-only targeted CAR-T therapies by simultaneously targeting both CD19 and CD20. In addition to the dual targeting, P-CD19CD20-ALLO1 uses a novel CD19 binder that showed greater potency in in vivo preclinical models when compared to the canonical FMC63 Single-chain variable fragment (scFv) binder. P-CD19CD20-ALLO1 is an off-the-shelf CAR-T therapy for which patients do not have to undergo apheresis and wait for cells to be manufactured, which can potentially overcome the limitation of autologous CAR-T therapies associated with significant manufacturing times. P-CD19CD20-ALLO1 is being studied in a Phase 1 study in B-cell malignancies. Additional information about the trial is available at www.clinicaltrials.gov using identifier: NCT06014762.

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. The Company's pipeline includes investigational allogeneic CAR-T cell therapies for hematologic cancers, autoimmune diseases, and solid tumors, 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 transposon-based 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 clinical data updates; anticipated timelines and milestones with respect to the Company's development programs; the potential capabilities and benefits of the Company's technology platforms and product candidates; 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 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 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 Company's ongoing and planned clinical trials; whether any of the Company's product candidates will be shown to be effective, safe or reliable; the Company's ability to finance continued operations; the fact that the Company will have limited control over the efforts and resources that Roche devotes to advancing development programs under its collaboration agreement with Roche; the fact that the Company may not receive the potential fees, reimbursements and payments under its collaboration agreement with Roche; the ability of Roche to early terminate the collaboration, such that the Company may not fully realize the benefits of the collaboration; and the other risks and uncertainties described in the Risk Factors section of the Company's Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on August 5, 2024, and in other filings the Company makes with the SEC from time to time. 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.