Final results of a phase I study of carfilzomib, lenalidomide, and dexamethasone for heavily pretreated multiple myeloma.

We report the final results from a multicenter, open-label phase I study of carfilzomib plus lenalidomide and dexamethasone in Japanese patients with heavily pretreated relapsed and/or refractory multiple myeloma (RRMM). Twenty-six RRMM patients were enrolled and received a median of 4.0 prior regimens; 12/26 patients (46.2%) completed the planned 18 administration cycles (mean number of cycles: 14.5 ± 4.9). The safety profile was consistent with that of previous carfilzomib studies. All patients experienced adverse events (AEs), but no new safety concerns were observed. The most common grade ≥ 3 AEs (incidence: ≥ 10%) were lymphocyte count decreased (46.2%), platelet count decreased (42.3%), and neutrophil count decreased (34.6%). The overall response rate was 88.5% (23/26; 90% confidence interval: 72.8-96.8). Complete response (CR) or better was achieved by 30.8% of patients compared with 3.8% in the interim analysis. The median time to CR or better response was 9.4 months. Median progression-free survival and duration of response were 19.5 months and 20.3 months, respectively. Median overall survival was not reached. Long-term administration of carfilzomib produced deep response and long-term disease control. The combination of carfilzomib plus lenalidomide and dexamethasone was well tolerated and showed promising clinical efficacy for heavily pretreated RRMM patients. CLINICAL

trial registrationThis clinical trial was registered in the database clinicaltrials.jp (clinical trial registration number: Japic CTI 142677).