Ixazomib, lenalidomide, and dexamethasone combination in "real-world" clinical practice in patients with relapsed/refractory multiple myeloma

Ixazomib is approved for use in combination with lenalidomide and dexamethasone (IRd) for patients with multiple myeloma (MM) who received at least one previous therapy. Registration study "TOURMALINE MM-1" was published in 2016. Nevertheless, clinical trials are significantly different from real-world use. From June 2016 to December 2018, IRd was available for Slovak patients with relapsed/refractory MM through a Named Patient Program. The aim of this study was to evaluate the efficacy and safety of ixazomib. We analyzed in this cohort study outcomes of 106 MM patients treated with IRd at 2 academic centers. The median age at diagnosis was 63 years (44-78). The median number of prior lines was 2 (1-7). The majority had high international staging system (ISS) score: 18, 29, and 59 were in the ISS I, ISS II, and ISS III groups, respectively. Treatment continued until progression, unacceptable toxicity, or death. The median follow-up for the entire cohort was 29 (0-49) months. The overall response rate was 74.5% (complete remission, 7.5%; partial remission, 67%). The median overall survival was not reached. Median progression-free survival (PFS) was 43 months (95% CI 35.6-50.4). The Kaplan-Meier method was used to generate survival curves, and we compared the influence of different factors on PFS. The most common hematological adverse events of any grade were neutropenia (90.4%), anemia (55.6%), and thrombocytopenia (43.4%). Our real-world data support the use of IRd as a highly effective and well-tolerated oral treatment protocol for relapsed myeloma.