Daratumumab in multiple myeloma: experience of the multiple myeloma GIMEMA Lazio group

Daratumumab (DARA) is a human IgG-K monoclonal antibody (MoAb) targeting CD38 that is approved alone or in combination with bortezomib and dexamethasone or lenalidomide and dexamethasone for relapsed or refractory MM (RRMM) in patients previously exposed or double refractory to proteasome inhibitors (PI) and immunomodulatory drugs (IMiDs). However, there are limited data on its clinical activity and tolerability in real-world patients. Therefore, in the present study, we aim to determine the efficacy and toxicity profile of daratumumab in a real-life setting. In this study, we report the experience of the multiple myeloma GIMEMA Lazio Group in 62 relapsed/refractory MM patients treated with daratumumab as monotherapy who had previously received at least two treatment lines including a PI and an IMiDs or had been double refractory. Patients received DARA 16 mg/kg intravenously weekly for 8 weeks, every 2 weeks for 16 weeks, and every 4 weeks until disease progression or unacceptable toxicity. The overall response rate to daratumumab was 46%. Median progression-free survival (PFS) and overall survival reached 2.7 and 22.4 months, respectively. DARA was generally well tolerated; however, 2 patients interrupted their therapy due to adverse events. Present real-life experience confirms that DARA monotherapy is an effective strategy for heavily pre-treated and refractory patients with multiple myeloma, with a favorable safety profile.