Idecabtagene vicleucel (Ide-cel) chimeric antigen receptor (CAR) T-cell therapy for relapsed/refractory multiple myeloma (RRMM): Real-world experience

ABSTRACT

Background: Ide-cel, a BCMA directed CAR T-cell therapy, was FDA approved 3/26/2021 for the treatment of RRMM after 4 prior lines of therapy. We evaluated the real-world outcomes of patients treated with standard of care ide-cel under the commercial FDA label. Methods: Ten US academic centers contributed data to this effort independent of the manufacturer. As of 1/10/2022, 138 patients were leukapheresed with overall manufacturing failure in 6 (4%). 108 patients were infused ≥ 30 days prior to data-cut off and constitute the study population for this retrospective analysis. Results: Table describes the study population compared to the pivotal KarMMa-1 trial (Munshi et al, NEJM 2021). Patients in our study were less likely to have ECOG PS of 0/1 (77%) and more likely to be penta-refractory (41%). 67% of patients would not have met eligibility criteria for KarMMa. Common reasons for ineligibility (> 1 reason in 22% patients) were co-morbidities (28%), cytopenias (22%), prior therapy with alloSCT/ CAR-T/other BCMA therapy (19%), CNS myeloma/non-measurable disease/plasma cell leukemia (13%), and fitness (12%). 81% of patients received bridging therapy. Toxicity was comparable to that seen in KarMMa-1. Cytokine release syndrome (CRS) was seen in 82% (> grade 3 4%) and immune effector cell-associated neurotoxicity syndrome (ICANS) in 15% (> grade 3 5%) of patients, respectively. Tocilizumab and steroids were used in 72% and 25% of patients, respectively. Infections were seen in 34% of patients. Day 30 response was evaluable in 104 patients. Response rates were ≥ partial response, 83%;≥ very good partial response, 64%;and ≥ complete response (CR), 34%. 11% of patients have died by data cut-off, 7 due to disease progression and 5 due to other causes (1 grade 5 CRS, 1 hemophagocytic lymphohistiocytosis, 1 progressive neurological weakness, 2 COVID-19). Conclusions: This multicenter retrospective study delineates the real-world outcomes of ide-cel CAR T-cell therapy for RRMM. Despite more patients being penta-refractory and less fit compared to the pivotal KarMMa trial, safety and 30-day responses in the real-world setting (overall response rate 83%, CR 34%) are comparable to the clinical trial population. Follow-up is ongoing and updated data will be presented.