Idecabtagene vicleucel (ide-cel, bb2121), a BCMA-directed CAR T cell therapy, in relapsed and refractory multiple myeloma: Updated KarMMa results.
Authors: Larry D. Anderson, Jr, Nikhil C. Munshi, Nina Shah, Sundar Jagannath, Jesus G. Berdeja, Sagar Lonial, Noopur S. Raje, David Samuel DiCapua Siegel, Yi Lin, Albert Oriol, Philippe Moreau, Ibrahim Yakoub-Agha, Michel Delforge, Fabio Petrocca, Payal Patel, Liping Huang, Timothy B. Campbell, Kristen Hege, Jesús F. San-Miguel
Journal: Journal of Clinical Oncology (2021)

8016 Background: Patients (pts) with RRMM previously exposed to immunomodulatory agents, proteasome inhibitors (PIs), and CD38 antibodies (mAbs) have poor outcomes with subsequent treatments. Ide-cel, a BCMA-directed CAR T cell therapy, showed frequent, deep, and durable responses in heavily pretreated pts with RRMM in the pivotal KarMMa trial (Munshi NC, et al. J Clin Oncol 2020;38[suppl 15]. Abstract 8503). Here, we present updated data. Methods: Pts with ≥ 3 prior regimens (including immunomodulatory agent, PI, and CD38 mAb) and refractory to their last regimen per IMWG criteria were eligible (NCT03361748). Pts received 150─450 × 106 CAR+ T cells (target dose range) after 3 days of lymphodepletion (cyclophosphamide 300 mg/m2 + fludarabine 30 mg/m2). Endpoints included overall response rate (ORR; primary) and complete response (CR) rate (key secondary). Additional secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety. Results: KarMMa enrolled 140 pts, and 128 received ide-cel. Pts had a median age of 61 years and a median of 6 (range, 3-16) prior regimens; 84% were triple-class refractory, and 26% were penta-class refractory (lenalidomide, pomalidomide, bortezomib, carfilzomib, and daratumumab). Most pts (88%) had bridging therapy. Median follow-up was 15.4 mo (data cutoff, 7 Apr 2020). ORR was 73% and median PFS was 8.8 mo in all treated pts; both increased with higher dose (Table). At the highest target dose (450 × 106 CAR+ T cells), the ORR was 81%, the CR rate was 39%, and the median PFS increased to 12.2 months with longer follow-up. Responses were observed in all subgroups including difficult-to-treat subsets (eg, extramedullary disease [ORR, 70%], high tumor burden [71%], and R-ISS stage III disease [48%]). OS continues to mature and the median has not been reached; the 15-month event-free rate for OS was 71%. Cytopenias (97%) and cytokine release syndrome (CRS; 84%) were the most common any-grade toxicities. CRS was mostly grade 1/2; 5 pts (4%) had grade 3, 1 had grade 4 (at 300 × 106), and 1 had grade 5 (at 300 × 106). Investigator-identified neurotoxicity was reported in 23 pts (18%); 4 pts (3%) had grade 3 and 0 had grade ≥ 4. Tocilizumab was used in 67 and 3 pts with CRS and neurotoxicity, respectively. Conclusions: Updated results from the KarMMa trial continue to demonstrate deep, durable responses with ide-cel in heavily pretreated pts with RRMM. Efficacy and safety reflect prior reports and support a favorable clinical benefit-risk profile for ide-cel across the target dose range. Clinical trial information: NCT03361748.Dose, × 106 CAR+ T cells 150 (n = 4) 300 (n = 70) 450 (n = 54) Total (N = 128) ORR, n (%) 2 (50) 48 (69) 44 (81) 94 (73) CR/sCR, n (%) 1 (25) 20 (29) 21 (39) 42 (33) Median DOR, mo* † 9.9 11.3 10.7 Median PFS,mo* † 5.8 12.2 8.8 sCR, stringent CR. *Kaplan-Meier estimate. †Not reported due to small n.