Experience of Daratumumab in Relapsed/Refractory Multiple Myeloma: A Multicenter Study from Turkey

This study aimed to evaluate patients with RRMM who underwent daratumumab (DARA) therapy.This multicenter and retrospective study included 134 patients who underwent at least two courses of DARA from February 01, 2018 to April 15, 2022. Epidemiologic, disease and treatment characteristics of patients and, treatment related side effects were evaluated. Survival analysis were performed.The median age at initiation of DARA therapy was 60 (35-88) years. The median time to initiation of DARA and the median follow-up time were 41.2 (5.1-223) and 5.7 (2.1-24.1) months, respectively. The ORR after DARA therapy was 75 (55.9%), and ≥VGPR was observed in 48 (35.8%) patients. Overall survival (OS) and progression-free survival (PFS) for all patients were 11.6 (7.8-15.5) and 8.0 (5.1-10.9) months, respectively. OS was higher for patients undergoing DARA-Vd than for those undergoing DARA-Rd (16.9 vs. 8.3 months; p=0.014). Among patients undergoing Dara-Rd, PFS was higher in those without EMD (EMD-) than those with EMD (EMD+)(NA vs. 3.7 months; OR, 3.4; p < 0.001). The median number of prior therapies was 3 (1-8). Initiation of DARA therapy in the early period provides OS and PFS advantage, although statistically insignificant. Infusion-related reactions were observed in 18 (13.4%) patients. All reactions occurred during the first infusion and most reactions were grade 1-2 (94.5%). The frequency of neutropenia and thrombocytopenia was higher in the DARA-Rd group (61.9% vs. 24.7%; p < 0.001 and 42.9% vs. 15.7%; p < 0.001).Our study reflects real-life data in terms of DARA therapy for patients with RRMM and supports the early initiation of DARA therapy.