Outcomes of Daratumumab, Pomalidomide, and Dexamethasone, Followed by High-dose Chemotherapy and Autologous Stem Cell Transplantation, in Patients With Relapsed/Refractory Multiple Myeloma

The number of therapeutic options for patients with relapsed/refractory multiple myeloma has increased significantly. We treated 18 patients with relapsed/refractory multiple myeloma with DPd (daratumumab, pomalidomide, dexamethasone) as salvage therapy followed by high-dose chemotherapy and autologous stem cell transplantation. The overall response rate after salvage treatment with DPd was 100% and at day 100 after autologous stem cell transplantation was 100%; 67% achieved a complete response or better. No reported treatment-related mortality had occurred by day 100. The 2-year progression-free survival and overall survival rates were 83.3% and 94.4%, respectively. Background: The number of therapeutic options for patients with relapsed/refractory multiple myeloma (RRMM) has increased significantly. Our institute treated a series of patients with RRMM using DPd (daratumumab, pomalidomide, dexamethasone) as salvage therapy, followed by high-dose chemotherapy (HDCT) and autologous stem cell transplantation (ASCT). Patients and Methods: We treated 18 patients with RRMM from May 2016 to April 2020, with DPd as salvage therapy, followed by HDCT and ASCT. DPd was administered as daratumumab 16 mg/kg weekly for cycles 1 and 2, every 2 weeks for cycles 3 to 6, and then every 4 weeks. Pomalidomide was given at 4 mg orally on days 1 to 21 of a 28-day cycle, and dexamethasone at 20 or 40 mg weekly. Results: The patients had received a median of 2 (range, 1-4) previous regimens. Of the 18 patients, 13 (72%) had received ASCT before this treatment. In addition, 78% had disease refractory to proteasome inhibitors, 78% refractory to immunomodulatory agents, and 72% double refractory to immunomodulatory agents and proteasome inhibitors. The overall response rate after salvage treatment with DPd was 100% and at day 100 after ASCT was 100%; 67% had achieved a complete response or better and 78% had achieved a very good partial response or better. No treatment-related mortality had occurred by day 100. The 2-year progression-free and overall survival rates were 83.3% and 94.4%, respectively. The most common grade >= 3 adverse events were thrombocytopenia (100%), neutropenia (100%), and neutropenic fever (67%). Conclusions: DPd as salvage therapy, followed by HDCT and ASCT, demonstrated deep, durable, and clinically meaningful responses with a manageable safety profile in patients with RRMM. (C) 2020 Elsevier Inc. All rights reserved.