Phase 1b used a standard 3 + 3 dose-escalation scheme to determine the MTD. For each combination regimen, oprozomib doses were to be escalated in sequential cohorts of 3 participants with expansion to up to 6 participants if a dose-limiting toxicity (DLT) was observed in 1 of the first 3 participants. The doses of lenalidomide, cyclophosphamide, and dexamethasone were to remain fixed in all dose cohorts.
The phase 2 portion of the study was to include up to 35 additional participants in each of the 2 combination regimens, treated at the recommended phase 2 dose (RP2D) of oprozomib that was identified during the phase 1b portion of the study in order to better characterize safety and tolerability, and antimyeloma activity.
This study was stopped by sponsor decision during the dose escalation in phase 1b prior to initiation of phase 2.
