Outcomes of daratumumab, pomalidomide, and dexamethasone (DPd) followed by high-dose chemotherapy and autologous stem cell transplantation (HDCT/ASCT) in patients with relapsed/refractory myeloma RRMM.

Abstract

e20508 Background: The number of therapeutic options for patients with RRMM has increased significantly. Our institute treated a series of patients with induction therapy consisting of DPd followed by HDCT/ASCT. We present the early outcomes of these patients. Methods: We treated 16 patients with RRMM at the University of Kansas Health System between May 2016 and October 2019, with DPd as induction therapy followed by HDCT/ASCT. DPd was administered as Daratumumab 16 mg/kg weekly for cycles 1 and 2, every 2 weeks for cycles 3-6, and then every 4 weeks; pomalidomide was dosed at 4 mg orally on days 1-21 of a 28-day cycle; and dexamethasone 20 or 40 mg weekly. Responses were evaluated using the 2016 International Myeloma Working Group (IMWG) criteria. Results: Patients had received a median of two prior regimens. Out of the 16 patients: 81% received ASCT prior to this treatment. In addition, 75%,81% and 68% were refractory to proteasome inhibitors (PI), immunomodulatory agents (IMiDs), and double refractory to IMiDs and PI, respectively. Median time from diagnosis to treatment was 12 months. Median number of DPd cycles received was 4 cycles. A median follow-up of 27 (9-39) months, the overall response rate (ORR) after induction treatment with DPd was 100%. ORR on day 100 post ASCT was 100%, 65% achieved ≥CR, and 81% achieved ≥VGPR. There was no treatment related mortality on day 100. Median progression free survival was 34 months (95%, CI = NA), median overall survival was not reached. The most common grade ≥ 3 adverse events were thrombocytopenia 53%, anemia 40%, neutropenia 53%. Conclusions: DPd as induction therapy followed by HDCT/ASCT demonstrated deep, durable, and clinically meaningful responses with manageable safety profile in patients with RRMM. [Table: see text]