A Phase 2, Open-Label, Multicenter Study of Ixazomib Plus Lenalidomide and Dexamethasone in Adult Japanese Patients with Relapsed and/or Refractory Multiple Myeloma

Abstract

Background: TOURMALINE-MM1 was a global study that demonstrated a significant improvement in progression-free survival with ixazomib plus lenalidomide and dexamethasone compared with placebo plus lenalidomide and dexamethasone, in patients with relapsed and/or refractory multiple myeloma. The current study was conducted to evaluate further the efficacy and safety of ixazomib plus lenalidomide and dexamethasone in Japanese patients.

Methods: This phase 2, open-label, single-arm, multicenter study enrolled patients aged ≥ 20 years with relapsed and/or refractory multiple myeloma at 16 sites in Japan. Patients refractory to lenalidomide or proteasome inhibitor-based therapy at any line were excluded. The primary endpoint was the rate of very good partial response or better in the response-evaluable analysis set. Secondary endpoints were progression-free survival, overall response rate, duration of response, time to progression, overall survival and safety.

Results: In total, 34 patients were enrolled. The rate of very good partial response or better was 50.0% (95% confidence interval 31.9-68.1) and the overall response rate was 84.4% (95% confidence interval 67.2-94.7). Median progression-free survival was 22.0 months (95% confidence interval 17.3-not evaluable) and median overall survival was not estimable. The safety profile of ixazomib plus lenalidomide and dexamethasone in this study was similar to that in the TOURMALINE-MM1 study.

Conclusions: The efficacy and safety of ixazomib plus lenalidomide and dexamethasone in Japanese patients with relapsed and/or refractory multiple myeloma are comparable with reported TOURMALINE-MM1 study results.