Second Primary Malignancies After Commercial CAR T Cell Therapy: Analysis of FDA Adverse Events Reporting System (FAERS).

Second primary malignancies (SPMs) were reported in 536 out of 12,394 (4.3%) adverse event reports following CAR T cell therapies in the FDA Adverse Event Reporting System (FAERS). Myeloid and T-cell neoplasms were disproportionately more frequently reported, warranting further follow-up.