DREAMM-11, Part 2: Japanese phase I trial of belantamab mafodotin combination therapies in relapsed/refractory multiple myeloma

DREAMM-11 (NCT03828292) was a Phase 1, open-label, dose-escalation study of belantamab mafodotin in Japanese patients with relapsed/refractory multiple myeloma (RRMM). In Part 1, belantamab mafodotin monotherapy (2.5 or 3.4 mg/kg every 3 weeks) was tolerated and demonstrated clinical activity and a manageable safety profile. Part 2 investigated the tolerability, safety, clinical activity and pharmacokinetics of belantamab mafodotin (2.5 mg/kg on Day [D]1 of each 21-day cycle) plus bortezomib and dexamethasone (Arm A; N = 3) or belantamab mafodotin (2.5 mg/kg on D1 of the first 28-day cycle; 1.9 mg/kg on D1 of subsequent cycles) plus pomalidomide and dexamethasone (Arm B; N = 4) in Japanese patients with RRMM and ≥ 1 prior line of therapy. No dose-limiting toxicities were reported in Arm A; 1 (non-serious liver injury) was reported in Arm B. Safety profiles of each treatment combination were consistent with those of the individual agents and those in Western populations. An overall response was achieved by 3/3 (100%) patients in Arm A and 2/4 (50%) in Arm B. Pharmacokinetics were consistent between Japanese and Western populations. The clinical pharmacokinetics, safety, and efficacy data from this study can inform future use of belantamab mafodotin plus bortezomib/pomalidomide and dexamethasone in Japanese patients with RRMM.