Clinical Efficacy of Daratumumab in Monotherapy of Relapsed/Refractory Multiple Myeloma

Abstract

Background. Daratumumab is IgG1-K humanized anti-CD38 monoclonal antibody. It has a direct impact on tumor and immunomodulatory effect. Aim. To assess the efficacy of daratumumab monotherapy in patients with progressive, and relapsed/refractory multiple myeloma (MM), as well as to find out the degree of toxicity and safety of this drug. Materials & Methods. The trial included 10 MM patients (3 men and 7 women) aged 51-74 years (median 57 years). Stage 3 (according to Durie-Salmon system) was determined in all patients, in 2 of them stage 3B with creatinine clearance < 30 mL/min was reported. According to ISS (International Staging System) criteria, stage 2 and stage 3 were identified in 6 and 4 patients, respectively. All the patients had been previously treated with bortezomib and lenalido-mide with further double refractoriness in 4 out of 10 patients. Bendamustine and carfilzomib were administered to one patient each, both in combined regimens. The number of previous therapy lines was 3-6 (median 5). Results. Overall response was 50 % including 2 (20 %) patients with very good partial remission. In 1 (10 %) patient complete remission was achieved. During the follow-up of 6-32 months (median 15 months) median overall survival was not achieved. Median progression-free survival was 17.8 months. Daratumumab is characterized by favorable safety profile. In 20 % of patients infusion-induced reactions with severity grades 1-2 were observed. Among other adverse events the following should be pointed out: weakness (30 %), nausea (10 %), headache (10 %), anorexia (10 %), thrombocytopenia (20 %), and neutropenia (30 %). No serious complications were reported. Conclusion. Daratumumab treatment is a safe and effective method of anticancer drug therapy in relapsed/refractory MM.