A Study of Oprozomib, Pomalidomide, and Dexamethasone in Adults With Primary Refractory or Relapsed and Refractory Multiple Myeloma

This was a phase 1b/3, multicenter study composed of 2 parts: part 1 was a phase 1b, open-label, dose-escalation and dose-expansion component and part 2 was to have been a phase 3, placebo-controlled, double-blind, randomized component. Part 2 was not conducted. The Phase 1 dose-escalation portion of the study followed a standard 3 + 3 dose-escalation design. For each of the 2 schedules, groups of 3 to 6 patients were enrolled. The starting doses of oprozomib were 150 and 210 mg in the 5/14 and 2/7 schedules, respectively. The starting dose of pomalidomide was 4 mg in both schedules. As long as \< 33% of patients experienced a dose-limiting toxicity (DLT) in a given cohort, the dose of oprozomib was escalated in 30-mg increments for successive cohorts. Once the recommended dose and schedule for the expansion phase had been selected, additional participants were enrolled in the dose expansion portion of part 1 to continue the evaluation of the safety and efficacy of the regimen and determine the recommended phase 3 dose. Enrollment was halted during the dose expansion phase and part 2 was not conducted.