Efficacy and safety of ixazomib plus lenalidomide-dexamethasone (IRd) vs placebo-rd in patients (pts) with relapsed/refractory multiple myeloma (RRMM) by cytogenetic risk status in the global phase III Tourmaline-MM1 study.

8018Background: TOURMALINE-MM1 (NCT01564537) showed a significant 35% improvement in progression-free survival (PFS) with IRd vs placebo-Rd (hazard ratio [HR] 0.742, p = 0.012) in pts with RRMM (Moreau et al, ASH 2015). Here we present an analysis of the efficacy and safety of IRd vs placebo-Rd by cytogenetic status. Methods: Pts with RRMM were randomized 1:1 to receive IRd or placebo-Rd. High-risk cytogenetic abnormalities were assessed at a central laboratory; cut-off values were based on false-positive rates of the FISH probes, and were 5%, 3%, and 3% for del(17p), t(4;14), and t(14;16), respectively. Post-hoc analyses were performed using different cut-offs for del(17p) and t(4;14). Results: Of 722 pts enrolled, 552 (76%) had cytogenetic results (97% central laboratory-confirmed), of whom 137 had high-risk abnormalities (75 IRd, 62 placebo-Rd). PFS was improved with IRd vs placebo-Rd in high- and standard-risk pts (Table); in high-risk pts, median PFS with IRd was similar to that in all pts and in sta...