Phase 1b/2, Multicenter, Open-label Study of Oprozomib and Dexamethasone in Patients With Relapsed and/or Refractory Multiple Myeloma

The purpose of the Phase 1b portion of the study was to determine the maximum tolerated dose (MTD), the recommended phase 2 dose (RP2D), safety, and pharmacokinetics (PK) of oprozomib administered orally once daily in combination with dexamethasone, in participants with relapsed and/or refractory multiple myeloma, using a 3 + 3 dose-escalation scheme with and without step-up dosing. The MTD was defined as the highest dose level at which fewer than 33% of participants had a dose-limiting toxicity (DLT).