Pomalidomide, dexamethasone, and daratumumab in Japanese patients with relapsed or refractory multiple myeloma after lenalidomide-based treatment.

In cohort C of the phase 2 MM-014 trial, the efficacy and safety of pomalidomide, dexamethasone, and daratumumab therapy were investigated in 18 Japanese patients with relapsed/refractory multiple myeloma (RRMM) after their most recent regimen of lenalidomide-based therapy (NCT01946477). Patients received oral pomalidomide (4 mg daily), oral dexamethasone (20-40 mg weekly), and intravenously infused daratumumab (16 mg/kg). Median age was 67.5 years. All patients received prior lenalidomide per protocol; 89% received prior bortezomib. Twelve patients (67%) had lenalidomide-refractory disease, and 6 (33%) had lenalidomide-relapsed disease. Ten patients (56%) had only 1 prior treatment line. As of August 3, 2020, 15 patients (83%) were still on treatment; median follow-up was 8.1 months. Three patients (17%) discontinued treatment (2 for adverse events; 1 for major protocol deviation). Overall response rate (primary endpoint) was 83% (very good partial response or better, 61%). All patients had ≥ 1 grade 3/4 treatment-emergent adverse events, most commonly neutropenia (78%; febrile, 6%), leukopenia (28%), and lymphopenia (22%). Grade 3/4 infections occurred in 17%; 11% had pneumonia. In Japanese patients with RRMM, a triplet regimen of pomalidomide, dexamethasone, and daratumumab after early-line lenalidomide treatment failure showed high efficacy and safety consistent with the known safety profile.