Safety and Effectiveness of Elotuzumab in Japanese Patients with Relapsed/Refractory Multiple Myeloma: A Post-marketing Surveillance Study

Objective Elotuzumab plus lenalidomide and dexamethasone (ELd) was approved in Japan in 2016 for the treatment of relapsed/refractory multiple myeloma (RRMM). This post-marketing surveillance study evaluated the safety and effectiveness of ELd in RRMM patients during routine clinical practice in Japan. Methods Elotuzumab safety was assessed by evaluating adverse drug reactions (ADRs), and effectiveness was assessed primarily by the best overall response. Patients The study enrolled patients with RRMM who received ELd therapy between November 18, 2016, and June 18, 2017. The safety and effectiveness analysis sets included 831 and 755 patients, respectively. Results In the safety analysis set, patients received a median (range) of 12 (1-40) elotuzumab administrations over 108 (1-728) days of treatment. The relative dose intensity of elotuzumab was >= 90% in 74.1% of patients. ADRs and serious ADRs were reported in 41.2% and 15.2% of the patients, respectively. The most common ADR was infection (12.0%), followed by lymphocytopenia (10.1%), infusion reactions (7.5%), secondary malignancies (e.g., gastric cancer and pancreatic carcinoma), cataracts, and interstitial lung disease (0.2% each). While most patients with ADRs recovered, 71 discontinued treatment, and 14 deaths were reported. The presence of comorbidities, particularly cardiovascular disorders, significantly affected the safety. The overall response rate was 41.1%. Conclusion This all-case post-marketing surveillance study showed that ELd had an acceptable tolerability profile and promising clinical activity in Japanese patients with RRMM.