BCMA CAR-T therapy achieves 100% MRD negativity in transplant-ineligible multiple myeloma patients.

PURPOSE: Patients with newly diagnosed multiple myeloma (NDMM) who are ineligible for or not proceeding to autologous stem-cell transplantation (ASCT)-often because of age or frailty-have limited opportunities to receive multiple effective lines of therapy, underscoring the need for novel frontline strategies. METHODS: In this phase II, open-label, single-arm trial (ClinicalTrials.gov identifier: NCT05860036), patients received 3-4 cycles of protocol-allowed induction, followed by B-cell maturation antigen (BCMA) CAR-T infusion, and subsequent consolidation and lenalidomide maintenance. The primary end point was the rate of minimal residual disease (MRD) negativity (10) at Month three postinfusion. RESULTS: Between April 4, 2023, and December 26, 2024, 43 patients were screened, 40 were enrolled, and 36 received infusion (median age, 68 years [46-75]). In the infused cohort, the MRD negativity rate at Month three postinfusion was 100% (36 of 36; 95% CI, 90.3 to 100.0). With a median follow-up of 15.8 months postinfusion (range, 4.3-26.0), no MRD recurrence was observed. The complete response rate (CRR) increased from 33.3% (12 of 36; 95% CI, 18.6 to 51.0) preinfusion to 69.4% (25 of 36; 95% CI, 51.9 to 83.7) at Month 3% and 94.4% (34 of 36; 95% CI, 81.3 to 99.3) at last follow-up. The most common grade 3 to 4 adverse events were transient cytopenia, including lymphopenia (100%), neutropenia (88.9%), leukopenia (80.6%), thrombocytopenia (19.4%), and anemia (8.3%). Cytokine release syndrome occurred in 52.8% of patients (all grade 1 to 2), immune effector cell-associated neurotoxicity in 5.6% (all grade 1), and infections in 30.6% (grade ≥3 in 19.4%). No deaths or disease progressions occurred by cutoff. CONCLUSION: Frontline BCMA CAR-T therapy induces deep, rapid, and durable remissions with a manageable safety profile in the NDMM population ineligible for or not proceeding to ASCT. These findings support its investigation as a potentially practice-changing strategy for this population.