ASCO 2021: KarMMa Update of BCMA-Directed CAR T-Cell Therapy for Refractory Myeloma
Posted: Thursday, June 17, 2021
The B-cell maturation antigen (BCMA)-directed chimeric antigen receptor (CAR) T-cell therapy idecabtagene vicleucel continued to yield “deep and durable responses” for patients with relapsed and refractory multiple myeloma, according to an update from the phase II KarMMa trial presented during the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 8016). In particular, at the highest target dose (450 x 106 CAR-positive T cells), the overall response rate was 81%, with a complete response rate of 39%.
“Efficacy and safety reflect prior reports and support a favorable clinical benefit-risk profile for idecabtagene vicleucel across the target dose range,” stated Larry D. Anderson, Jr, MD, PhD, of The University of Texas Southwest Medical Center, Dallas, and colleagues.
In this open-label, single-arm, multicenter study, patients with multiple myeloma who had undergone at least three prior regimens and were refractory to the most recent treatment were enrolled (n = 140). Following 3 days of lymphodepletion chemotherapy, 91.4% of enrolled patients received infusions of CAR-positive T cells at a dose ranging from 150 to 450 x 106. A total of 128 received the investigational therapy.
At the median follow-up of 15.4 months, patients who had received the infusions had an overall response rate of 73%, and the median progression-free survival was 8.8 months. Antitumor activity appeared to be positively correlated with higher dosages. At the highest infusion dose, the complete response rate was 39%, the overall response rate was 81%, and the median progression-free survival was 12.2 months. Antitumor activity was observed in all patients, including those with extramedullary disease, a high tumor burden, and stage 3 disease (Revised International Staging System). The median overall survival has not yet been reached.
The most common adverse effects were cytopenias (97%) and cytokine-release syndrome (84%), at levels of grade 1 or 2 in the majority of patients. In 21% of patients, neurotoxicity was observed and treated with tocilizumab.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.