Piggybacking toward Progress for CAR T-Cell Therapy in Prostate Cancer.

P-PSMA-101 is a first-in-class, stem cell memory T cell-enriched, prostate-specific membrane antigen (PSMA)-targeting chimeric antigen receptor (CAR) T therapy. This cellular therapy showed notable clinical activity in two patients; however, PSA50 responses were generally modest. Although severe immune effector-related toxicities were observed in some patients, a novel inducible caspase 9 (iCasp9) safety switch was largely effective in mitigating toxicity. See related article by Slovin et al., p. 3540.