Evaluation of Real-World Studies on Management of Relapsed Multiple Myeloma After BCMA-Directed Therapy Failure from U.S. Academic Centers and USMIRC.

B-cell maturation antigen (BCMA)-directed therapies (BDTs) have transformed relapsed/refractory multiple myeloma treatment, but optimal post-failure sequencing remains undefined. We evaluated real-world outcomes from three retrospective, multicenter analyses. Study 1 compared BCMA CAR-T and BCMA T-cell engagers (TCEs) in BDT-exposed patients (n = 95). Study 2 evaluated teclistamab in BDT-exposed versus BDT-naïve patients (n = 164). Study 3 examined talquetamab (GPRC5D-targeting TCE) in heavily pretreated patients (n = 68). CAR-T therapy achieved superior outcomes versus TCE (overall response rate [ORR] 79% vs. 51%, p < 0.001; median overall survival [OS] 30 vs. 12 months, p = 0.008). Teclistamab-treated BDT-exposed patients had lower ORR (53% vs. 68%, p = 0.02) and shorter median progression-free survival (PFS; 2.5 vs. 9.7 months, p = 0.01) compared with BDT-naïve patients. Administration < 6 months post-BDT showed inferior outcomes (hazard ratio [HR] 2.5 for PFS; HR 2.9 for OS). Talquetamab achieved an ORR of 68.3% among BDT-exposed patients, with significantly lower response rates when administered < 6 months post-BDT or when BDT was the immediate preceding treatment (56.8% vs. 84.6% and 48% vs. 80.6%, respectively). Treatment-free intervals of ≥6 months between T-cell-redirecting therapies improved efficacy and survival. Post-BDT sequencing should prioritize CAR-T therapy when feasible, allow >6-month intervals before BDT re-challenge, and utilize non-BCMA targets for early relapse or BDT-refractory disease.