Poseida Therapeutics, Inc.: management transactions · United States · SEC (Form 4)

About Poseida Therapeutics, Inc.

Poseida Therapeutics, Inc. (ticker: PSTX) is a United States biotechnology company that was listed on the NASDAQ and operated as a clinical-stage cell and gene therapy developer. Founded in 2014 through a corporate reorganization and spinout from Transposagen Biopharmaceuticals, Poseida built its business around proprietary non-viral gene engineering platforms and established its headquarters in San Diego, California, a major U.S. biotech hub. ([sec.gov](https://www.sec.gov/Archives/edgar/data/1661460/000095017024027998/pstx-20231231.htm?utm_source=openai)) From an operating standpoint, Poseida focused on developing therapies for areas of high unmet medical need, especially hematologic cancers, with additional work spanning solid tumors, rare diseases, and more recently autoimmune-related programs in its broader pipeline communications. Its core technology stack centered on three differentiated platforms: the piggyBac non-viral DNA delivery system, the Cas-CLOVER site-specific gene editing platform, and nanoparticle- and AAV-based delivery technologies. These capabilities positioned the company as a specialist in both allogeneic cell therapy and in vivo genetic medicine. ([sec.gov](https://www.sec.gov/Archives/edgar/data/1661460/000095017024027998/pstx-20231231.htm?utm_source=openai)) In competitive terms, Poseida was best known for pursuing off-the-shelf allogeneic CAR-T therapies, with a strong scientific emphasis on stem cell memory T cells (TSCM). That approach was intended to support better durability, potency, and safety relative to some earlier-generation cell therapy concepts. In 2024, the company highlighted progress around P-BCMA-ALLO1 for multiple myeloma and presented preclinical and early clinical updates across its broader cell-therapy pipeline. It also benefited from strategic collaborations with Roche and Takeda, which validated the platform while helping share development risk. ([poseida.com](https://poseida.com/news/poseida-therapeutics-highlights-positive-interim-phase-1-results-for-p-bcma-allo1-and-preclinical-data-for-dual-car-t-p-cd19cd20-allo1-at-the-66th-american-society-of-hematology-ash-annual-meeting/?utm_source=openai)) The most important recent development was Roche’s agreement in late 2024 to acquire Poseida, followed by the tender offer process and acceptance of tendered shares in early January 2025. Roche said the acquisition built on an existing collaboration in allogeneic CAR-T therapies. For investors, that means PSTX is no longer best viewed as a standalone public biotech story; instead, its value proposition became tied to Roche’s ownership, the closing mechanics, and any contingent value rights rather than to a conventional public-market growth narrative. ([roche.com](https://www.roche.com/investors/updates/inv-update-2024-11-26b?utm_source=openai))