Phase I study of carfilzomib, lenalidomide, vorinostat, and dexamethasone in patients with relapsed and/or refractory multiple myeloma

Research has shown that proteasome inhibitors (e.g., carfilzomib), immunomodulatory agents (e.g., lenalidomide), histone deacetylase inhibitors (e.g., vorinostat) and corticosteroids (e.g., dexamethasone) have synergistic anti-multiple myeloma (MM) activity. This phase I dose-escalation study evaluated a regimen combining carfilzomib, lenalidomide, vorinostat and dexamethasone (QUAD) in patients with relapsed and/or refractory MM. Seventeen patients received carfilzomib (15, 20, or 20/27 mg/m²; 30-min infusion; days 1, 2, 8, 9, 15, 16), lenalidomide (15 or 25 mg; days 1-21), vorinostat (300 or 400 mg; days 1-7, 15-21), and dexamethasone (40 mg; days 1, 8, 15, 22) in 28-d cycles. No dose-limiting toxicities were observed; the maximum tolerated dose was not reached. The maximum administered dose was carfilzomib 20/27 mg/m², lenalidomide 25 mg, vorinostat 400 mg, and dexamethasone 40 mg. Common grade ≥3 adverse events included neutropenia (53%), thrombocytopenia (53%) and anaemia (41%). The overall response rate was 53%: 12% of patients achieved a very good partial response (PR) and 41% of patients achieved a PR. At a median follow-up of 10 months, median progression-free survival was 12 months and median overall survival was not reached. Treatment with QUAD was feasible and had encouraging activity in patients with relapsed and/or refractory MM.