Efficacy and safety of ixazomib in Chinese patients with multiple myeloma

Objective：To evaluate the efficacy and safety of ixazomib, an oral proteasome inhibitor, in patients with multiple myeloma (MM). Methods：MM patients (patients with light chain amyloidosis and plasma cell leukemia were excluded) received 2 cycles or more of ixazomib therapy were selected in Zhongshan Hospital, Fudan University Between July 1, 2018 and April 4, 2019. The treatment included single ixazomib agent and doublet- or triplet-drug regimens combined with other agents (lenalidomide, thalidomide, or dexamethasone, etc.). Patients received ixazomib at an initial dose of 4 mg (day 1, 8, and 15) in a 28-days cycle. Response assessment and safety were analyzed in all patients at the end of the 2nd cycle and 4th cycle. Results：A total of 27 eligible patients including 15 refractory/relapsed MM and 12 newly diagnosed MM were enrolled. The overall response rate (ORR) in refractory/relapsed MM was 53.3%, with 2 patients had complete response (CR), 1 had very good partial response (VGPR), 5 had partial response (PR). The median time to response was 53 d in refractory/relapsed patients. The ORR was 54.5% (6/11) in bortezomib-refractory patients. The ORR in 9 evaluable previously untreated MM patients was 100.0%, with 2 had CR, 3 had VGPR, and 4 had PR. The median time to response was 38 d in newly diagnosed patients. Grade 3-4 adverse events (AE) were reported in 29.6% patients. Common hematological AEs included lymphopenia, neutropenia, thrombocytopenia, and anemia. Other common AEs were fatigue and gastro-intestinal response. No grade 3-4 peripheral neuropathy was recorded. Conclusions：In real-world setting, ixazomib is generally effective and safe in newly diagnosed and relapsed/refractory MM patients in China.