Pomalidomide, Bortezomib, and Dexamethasone Versus Bortezomib and Dexamethasone in Relapsed or Refractory Multiple Myeloma: Final Survival and Subgroup Analyses From the OPTIMISMM Trial.

Introduction: In the OPTIMISMM trial, pomalidomide/bortezomib/dexamethasone (PVd) significantly prolonged median progression-free survival (PFS) versus bortezomib/dexamethasone (Vd) in lenalidomide-exposed relapsed and refractory multiple myeloma (RRMM). We report final overall survival (OS) and updated efficacy analyses.

Methods: Adults with RRMM who had 1-3 prior regimens, including lenalidomide (≥ 2 cycles), were assigned (1:1) to PVd or Vd.

Primary Endpoint: PFS. Prespecified secondary endpoint: OS. Prespecified exploratory endpoints: PFS2 and subgroup efficacy analyses.

Results: With an overall event rate of 70.0%, OS data were mature in the intent-to-treat population (N = 559). After median follow-up of 64.5 months (data cutoff: May 13, 2022), median OS was 35.6 months with PVd versus 31.6 months with Vd (HR 0.94, 95% CI 0.77-1.15, p = 0.571); adjusting for subsequent therapies, OS improved with PVd versus Vd (HR 0.76, 95% CI 0.619-0.931, p = 0.008). Median PFS2 was 22.1 versus 16.9 months, respectively (HR 0.77, 95% CI 0.64-0.94, nominal p = 0.008). Treatment-emergent adverse events led to study drug discontinuation in 92 (33.1%) and 53 (19.6%) patients in PVd and Vd arm, respectively.

Conclusions: Findings showed a nonsignificant trend towards improved OS with PVd versus Vd. PFS2 favored PVd, supporting its use in RRMM.