FDA Approval Summary: Idecabtagene Vicleucel for Relapsed or Refractory Multiple Myeloma

Abstract

In March 2021, the FDA approved idecabtagene vicleucel, a chimeric antigen receptor T-cell therapy targeting the B-cell maturation antigen (BCMA), for adult patients with relapsed/refractory multiple myeloma (RRMM) after ≥4 lines of therapy including an immunomodulatory agent, a proteasome inhibitor, and an antiCD38 mAb. Approval was based on overall response rate (ORR), complete response (CR) rate, and duration of response (DOR) in 100 adult patients with RRMM treated with idecabtagene vicleucel in a single-arm trial. Patients received a single infusion of idecabtagene vicleucel, preceded by lymphodepleting chemotherapy with cyclophosphamide and fludarabine. Of the 100 patients in the efficacy evaluable population, ORR was 72% [95% confidence interval (CI), 62–81] with stringent CR rate of 28% (95% CI, 19–38). After median follow-up of 10.7 months, median DOR was 11 months (95% CI, 10.3–11.4) in responders (partial response or better) and 19 months [95% CI, 11.4 months, not estimable (NE)] in patients who achieved stringent CR. Serious adverse reactions occurred in 67% of 127 patients evaluated for safety. Grade 3 or higher cytokine release syndrome and neurologic toxicities occurred in 9% and 4%, respectively, leading to a Risk Evaluation and Mitigation Strategy. Hemophagocytic lymphohistiocytosis/macrophage activation syndrome occurred in 4%, with two fatalities. Prolonged cytopenia requiring hematopoietic rescue occurred in 2% (3/127), with two fatalities.