Efficacy of daratumumab monotherapy in real-world heavily pretreated patients with relapsed or refractory multiple myeloma

Purpose: Daratumumab is a promising new agent for relapsed/refractory multiple myeloma (RRMM). However, there are limited data on its clinical activity and tolerability in the real-world patients. The purpose of this study is to determine the efficacy and toxicity profile of daratumumab monotherapy in the real-life setting. Patients and methods: Thirty RRMM patients treated with daratumumab who had previously received at least three treatment lines including a proteasome inhibitor and an immunomodulatory drug or had been double refractory (DR-MM) were included to the Polish Myeloma Group observational study. Results: The objective response rate to daratumumab was 42.8%. Median progression-free survival (PFS) and overall survival reached 9.5 and 13.8 months, respectively. Importantly, patients with DR-MM had a significantly shorter PFS than other patients (median PFS of 4.1 vs. 12.1 months). Daratumumab was generally well tolerated, however two patients had their therapy interrupted due to adverse events. Conclusion: Daratumumab monotherapy has significant activity and good tolerance in heavily pretreated RRMM patients.