Targeting castration resistant prostate cancer (CRPC) with autologous PSMA-directed CAR+ T cells.

TPS4700 Background: Based on our preclinical animal models, we initiated a phase I dose-escalating study to assess safety, dose requirement and targeting efficiency of genetically directed autologous human T cells targeted to Prostate Specific Membrane Antigen (PSMA). Our approach is based on the infusion of autologous PSMA-targeted T cells utilizing the P28z second generation chimeric antigen receptor (CAR) in patients (pts) with metastatic CRPC, following iv cyclophosphamide (Cy) (trial NCT01140373). For safety, the herpes simplex virus-1 thymidine kinase (hsvtk) gene is co-expressed with the P28z receptor, and renders T cells sensitive to ganciclovir for immediate T cell elimination if needed. The expression of hsvtk enables PET imaging using radiolabeled FIAU to localize adoptively transferred T cells. The aims of the trial are to assess: (1) safety of PSMA-targeted T cells; (2) biologic and anti-tumor effects; (3) T cell persistence at tumor site; and (4) immune response. Methods: Autologous T cells ...