Pembrolizumab, lenalidomide and dexamethasone post autologous transplant in patients with high‐risk multiple myeloma

Patients with high-risk multiple myeloma (hrMM) relapse after autologous stem cell transplantation (ASCT) with a median progression free survival (PFS) of 8-14 months without lenalidomide maintenance and 24-39 months with lenalidomide maintenance. We hypothesized that Pembro-Rd will prolong PFS post-ASCT in patients with hrMM compared to historical controls. This Phase II study enrolled hrMM patients with primary objective to assess the efficacy of the combination of Pembro-Rd for a total of 2 cycles and then an additional 2 cycles without dexamethasone. There were 12 evaluable subjects, as enrollment was stopped after an FDA hold. With a median follow-up of 50.7 months, the median PFS was 27.7 months. The PFS rates at years 1 and 2 are 90.9% and 63.6%, respectively. The most common adverse events were neutropenia (grade 1-3), cough, diarrhea and constipation, all grade 1 or 2. The PFS rate with fixed duration therapy was comparable to that seen with continuous dose lenalidomide, potentially offering a new post-ASCT therapeutic strategy. This article is protected by copyright. All rights reserved.