Background/Objectives: Teclistamab is a bispecific antibody targeting BCMA and CD3, approved for relapsed/refractory multiple myeloma. It is administered continuously until progression or intolerance; however, prolonged use may increase infections and treatment burden. This study compares continuous versus fixed-duration teclistamab to determine whether treatment discontinuation after response is feasible without compromising outcomes. Methods: A multicenter retrospective study was conducted on adults with relapsed/refractory multiple myeloma treated with teclistamab between August 2022 and May 2024. Patients received step-up dosing followed by weekly administration. Those who achieved ≥VGPR and discontinued therapy due to deep response, toxicity, or preference were assigned to the fixed-duration group. Outcomes included response rates, progression-free survival (PFS), overall survival (OS), and adverse events. Results: Eighty-eight patients were included (continuous: n = 72; fixed: n = 16). The fixed group had higher complete response rates (69% vs. 44%) and shorter median time to best response (1 vs. 2 months). Median PFS was 16 months for continuous dosing versus 13 months for fixed-duration. Twelve-month PFS was similar (65% vs. 66%). Twelve-month OS was 83% vs. 81% in the continuous and fixed groups, respectively. Cytokine release syndrome and neurotoxicity rates were similar. Infections were more frequent and severe in the fixed cohort (75% any grade; 69% grade ≥ 3). Conclusions: Fixed-duration teclistamab after deep response appears feasible in appropriately selected patients, with comparable early survival outcomes to continuous treatment. Prospective studies are needed to define selection criteria, immune recovery markers, and optimal discontinuation timing.

Daratumumab-based triplet regimens have demonstrated efficacy in relapsed or refractory multiple myeloma (RRMM). However, direct comparisons between these combinations remain limited. This study evaluated the efficacy and safety of 2 such regimens, DPd (daratumumab, pomalidomide, and dexamethasone) and DKd (daratumumab, carfilzomib, and dexamethasone), in a real-world RRMM population. We conducted a multicenter retrospective cohort study including 399 patients with RRMM treated at three academic centers in the US. The patients received either DPd (n = 295) or DKd (n = 104). Progression-free survival (PFS), overall survival (OS), depth of response, and adverse event profiles were compared between the groups. The median PFS was 15 and 12 months in the DPd and DKd groups, respectively. The median OS was 38 months for DPd and was not reached in the DKd cohort. The differences in PFS (P = .2) and OS (P = .5) were not statistically significant. The overall response rates and depth of response were comparable across regimens. DPd was associated with higher rates of hematologic toxicity, particularly grade ≥ 3 neutropenia (36% vs. 23%) and leukopenia (26% vs. 14%), whereas DKd showed a greater incidence of cardiovascular adverse events (29% vs. 18%). DPd and DKd demonstrated similar clinical efficacies in RRMM patients, although their toxicity profiles differed. These findings highlight the importance of individualized treatment decisions considering underlying patient comorbidities and prior drug exposure. These findings support the use of either regimen in appropriate patient subsets, based on efficacy and distinct safety profiles.

Background: High-risk cytogenetic multiple myeloma (HRMM) confers inferior outcomes despite significant therapeutic advances. Real-world data characterizing contemporary treatment patterns across lines of therapy in this population are limited. Methods: We conducted a multicenter retrospective study of 205 patients with HRMM diagnosed between January 2009 and January 2024. High-risk cytogenetics were defined according to the International Myeloma Working Group (IMWG) and Revised International Staging System (R-ISS) criteria as the presence of del(17p), t(4;14), t(14;16), t(14;20), and/or gain/amplification of 1q21. Treatment regimens were categorized by the number of agents (doublet, triplet, quadruplet), mechanism of action (proteasome inhibitor [PI]-based, immunomodulatory drug [IMiD]-based, and anti-CD38 monoclonal antibody-based), and specific regimen composition. Treatment patterns were analyzed across three treatment eras and stratified by age (<70 vs. ≥70 years). Results: The cohort included 205 patients (median age, 62 years [interquartile range [IQR], 54–68 years]; 78.5% aged <70 years). Double-hit and triple-hit cytogenetics were present in 60.0% and 7.3% of patients, respectively. For first-line induction, triplet therapy predominated (81.0%, n = 166), followed by quadruplet (8.8%, n = 18), doublet (5.9%, n = 12), and multi-agent chemotherapy (2.9%, n = 6). By mechanism of action, PI + IMiD combinations were the most common (63.4%, n = 130), followed by PI-based (19.0%, n = 39), anti-CD38-based (10.2%, n = 21), and IMiD-based (2.9%, n = 6) regimens. Era-stratified analysis revealed a significant increase in quadruplet utilization from 3.2% in Era 1 (2009–2015) to 20.3% in Era 3 (2020–2024), with anti-CD38-containing frontline regimens administered to 26.6% of patients in the contemporary era (p < 0.001). Second-line induction was required in 50 patients (24.4%), with anti-CD38-based triplets comprising the most common approach (30.0%). Autologous stem cell transplantation (ASCT) was performed in 75.1% of patients overall, with significantly higher utilization in those aged <70 years (83.9% vs. 43.2%). Maintenance therapy was administered to 71.7% of patients (n = 147), with IMiD-based regimens predominating (53.1%), followed by PI + IMiD combinations (27.9%) and anti-CD38-containing regimens (10.2%). Despite intensive therapy, 69.4% of patients on maintenance experienced disease relapse, with higher rates observed in younger patients (74.8% vs. 41.7%). Conclusions: In this real-world HRMM cohort, the PI + IMiD triplet regimen remained the predominant induction approach, with a significant shift toward quadruplet and anti-CD38-containing regimens in the contemporary era. However, substantial relapse rates during maintenance underscore the continued unmet need in HRMM and support the early integration of novel therapeutic strategies, including quadruplet induction and BCMA-directed agents, in this population.

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.