Matching-adjusted indirect comparison of talquetamab vs selinexor-dexamethasone and vs belantamab mafodotin in patients with relapsed/refractory multiple myeloma.

Objective: Talquetamab is the first GPRC5D-targeting bispecific antibody approved for the treatment of triple-class exposed (TCE) relapsed/refractory multiple myeloma (RRMM). This matching-adjusted indirect comparison (MAIC) study was conducted to compare the effectiveness of talquetamab vs selinexor-dexamethasone (sel-dex) and vs belantamab mafodotin (belamaf) in patients with TCE RRMM.

Methods: An unanchored MAIC was performed using individual patient-level data from patients treated with subcutaneous talquetamab 0.4 mg/kg weekly (QW) and 0.8 mg/kg every other week (Q2W) from MonumenTAL-1 (NCT03399799/NCT04636552) and published summary data for sel-dex from STORM (NCT02336815) and belamaf from DREAMM-2 (NCT0325678). Patients from MonumenTAL-1 who met key eligibility criteria for STORM and DREAMM-2 were included. Outcomes of interest were overall response rate (ORR), complete response or better (≥CR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS).

Results: After adjustment for cross-trial differences, patients treated with both dosing schedules of talquetamab showed significantly better ORR, ≥CR, and DOR vs sel-dex and significantly higher ORR and ≥ CR vs belamaf; DOR was relatively similar to belamaf. PFS was significantly improved with talquetamab Q2W and numerically in favor of talquetamab QW vs sel-dex and significantly improved with both dosing schedules of talquetamab vs belamaf. OS was significantly improved with both dosing schedules of talquetamab vs sel-dex and was numerically in favor of both dosing schedules of talquetamab vs belamaf.

Conclusion: These analyses show superior effectiveness of both talquetamab dosing schedules vs sel-dex and vs belamaf for most outcomes and highlight talquetamab as an effective treatment option for patients with TCE RRMM.