Standard-of-Care Idecabtagene Vicleucel for Relapsed/Refractory Multiple Myeloma: A CIBMTR Analysis

• Largest real-world study of ide-cel CAR-T in RRMM (821 patients) shows favorable safety and efficacy profile that mirrors trial experience

• Significant comorbidities present in 77% patients. Large sample size allowed identification of prognostic factors for safety and efficacy

Idecabtagene vicleucel (ide-cel) was the first FDA approved CAR T cell therapy for multiple myeloma. However, as clinical trials are highly selective with stringent eligibility criteria, the objective of this study was to evaluate the safety and effectiveness of standard of care (SOC) ide-cel in the real world. Using the CIBMTR registry we evaluated 821 patients who received SOC ide-cel. Median follow-up was 11.6 months. Median age was 66 years, and the cohort included 31% patients ≥70 years, 15% Black, 7% Hispanic and 77% patients with at least one significant co-morbidity. The median number of prior lines of therapy was 7, 15% patients previously received BCMA-directed therapy, 17% had extramedullary disease and 27% had high-risk cytogenetics. Overall response rate was 73%, and complete response (CR) rate was 25%. Median progression-free survival was 8.8 months. Treatment-related mortality was reported in 6% of patients. Cytokine release syndrome was diagnosed in 80% of patients (grade >=3: 3%). Immune effector cell associated neurotoxicity syndrome was observed in 28% (grade >=3: 5%), with no cases of Parkinsonism reported. Clinically significant infections were seen in 45% of patients. Second primary malignancies were reported in 4%, including 1% myeloid malignancies. This is the largest real-world study of ide-cel CAR-T cell therapy in pts with RRMM. We observed a favorable safety and efficacy profile that mirrors trial experience, even in the setting of significant co-morbidities in 77% of patients, many of which would have made them ineligible for the registrational KarMMa clinical trial.