Pattern of Use and Efficacy of Daratumumab-based Therapy in Patients With Multiple Myeloma in a Real-world Setting: a Single Institution Experience

Abstract

Purpose: Multiple myeloma (MM) is an incurable hematologic malignancy, caused by the accelerated growth of clonal plasma cells leading to severe multiorgan failure. Several novel agents have been recently approved for the treatment of this diseases, including daratumumab, a human IgG kappa monoclonal antibody that targets CD38 on the surface of plasma cells. The objective of this retrospective study is to explore the pattern of use, safety and efficacy of daratumumab-based therapy among patients with both newly diagnosed multiple myeloma (NDMM) and relapsed/refractory multiple myeloma (RRMM) in a real-world setting at a single institution. Methods: 57 patients with MM treated with daratumumab based therapy, from 11/16/2015 to 3/16/2020, were included in the study. Kaplan-Meier method was used to estimate time to hematologic response, as well as progression free survival (PFS) after daratumumab initiation. Log-rank tests were applied to compare PFS among subgroups. Results: The overall hematologic response (ORR) to daratumumab based-therapy was 82.5% and the median progression-free survival (PFS) was 23.5 months. The ORR and PFS among NDMM patients vs RRMM patients were 80% and not reached vs 84.8% and 22 months respectively. Importantly, subgroup analysis based on cytogenetic risks, demonstrated that patients with standard risk cytogenetics sustained a marginally significantly prolonged PFS (24.0 vs 10.0 months, p=0.065) compared to those with high/intermediate risk cytogenetics. When stratified by the treatment line (1st vs 2nd-3rd vs >3rd) and treatment pattern (dara monotherapy vs. combination with PI vs. IMiD vs. PI + IMiD), there were no significant differences in PFS. Daratumumab was generally well tolerated, with no discontinuations due to adverse events.Conclusion: Daratumumab-based therapy has significant efficacy and very good tolerability among MM patients, in a real-world setting.