Elotuzumab plus lenalidomide and dexamethasone in relapsed/refractory multiple myeloma: Extended 4-year follow-up and analysis of relative progression-free survival from the randomized ELOQUENT-2 trial

Background: The randomized phase 3 ELOQUENT-2 study (NCT01239797) evaluated the efficacy and safety of elotuzumab plus lenalidomide and dexamethasone (ELd) versus lenalidomide and dexamethasone (Ld) in relapsed/refractory multiple myeloma (RRMM), and to date, has the longest follow-up of any monoclonal antibody in patients with RRMM. Methods: In this extended 4-year follow-up of the ELOQUENT-2 trial, the coprimary endpoints of progression-free survival (PFS) and overall response rate as well as the secondary endpoint of overall survival were assessed. In the absence of head-to-head trials comparing Ld-based triplet regimens to guide treatment selection, 4 randomized controlled trials—ELOQUENT-2, ASPIRE, TOURMALINE-MM1, and POLLUX—were indirectly compared to provide insight into the relative efficacy of these regimens in RRMM. Results: Data at 4 years were consistent with 2- and 3-year follow-up data: ELd reduced the risk of disease progression/death by 29% versus Ld (hazard ratio, 0.71) while maintaining safety. The greatest PFS benefit among the assessed subgroups was observed in patients at the median time or further from diagnosis (≥3.5 years) with 1 prior line of therapy, who had a 44% reduction in the risk of progression/death, and in patients in the high-risk category, who had a 36% reduction in favor of ELd. This regimen also showed a relative PFS benefit that was maintained beyond 50 months. Conclusions: The sustained PFS benefit and long-term safety of ELd at 4 years, similar to those observed at 2 and 3 years, support ELd as a valuable therapeutic option for the long-term treatment of patients with RRMM. © 2018 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society