Poseida Therapeutics (PSTX) Stifel's 2024 Virtual Cell Therapy Forum summary

Key program updates and near-term milestones

• Data updates for all three clinical-stage allogeneic CAR T programs are planned for the second half of the year, including hematological malignancies and solid tumor indications.

• A Cell Therapy R&D Day is scheduled for the fall, providing further insights and data releases.

• The company is leveraging its proprietary non-viral technology to differentiate its CAR T products, focusing on T stem cell memory cells for improved efficacy and safety.

• Strategic partnerships with Roche and Astellas provide validation and financial support, with $45 million in milestone payments received this year.

• The platform is being expanded to autoimmune indications, with ongoing work to determine the optimal strategy and timeline.

Technology and clinical approach

• Utilizes a non-viral, allogeneic CAR T platform, producing products rich in T stem cell memory cells, which are linked to deeper and more durable responses.

• Proprietary gene-editing tools knock out the T-cell receptor and partially edit beta-2-microglobulin, reducing allo rejection and improving cell persistence.

• Clinical manufacturing is performed in-house, supporting rapid program advancement and scalability.

• The approach enables off-the-shelf products with potential for outpatient administration and broader patient access.

Clinical data highlights

• BCMA program (P-BCMA-ALLO1) in multiple myeloma showed an 82% objective response rate in a heavily pretreated population, including patients previously treated with BCMA-directed agents.

• High response rates were observed even in patients who had failed prior autologous CAR T or bispecific therapies.

• Safety profile is favorable, with low rates of cytokine release syndrome (21%, all Grade 2 or less), neurotoxicity (6%, Grade 2 or less), and rare infections, supporting outpatient use.

• The CD19/CD20 dual-targeting program addresses antigen escape in lymphoma and is the first allogeneic dual CAR T against these targets in the clinic, with a data update expected by year-end.

• Solid tumor program (P-MUC1C-ALLO1) has shown early signs of efficacy and is refining lymphodepletion protocols, with further data expected later this year.