A Phase 3, Two-Stage, Randomized, Multicenter, Open-Label Study Comparing Mezigdomide (CC-92480), Bortezomib and Dexamethasone (MEZIVd) Versus Pomalidomide, Bortezomib and Dexamethasone (PVd) in Subjects With Relapsed or Refractory Multiple Myeloma (RRMM): SUCCESSOR-1

Inclusion Criteria \- Participant has documented diagnosis of MM and measurable disease, defined as any of the following:. i) M-protein ≥ 0.5 grams per deciliter (g/dL) by serum protein electrophoresis (sPEP) or. ii) M-protein ≥ 200 milligrams (mg) per 24-hour urine collection by urine protein electrophoresis (uPEP). iii) For participants without measurable disease in sPEP or uPEP: serum free light chain (sFLC) levels \> 100 mg/L (10 mg/dL) involved light chain and an abnormal kappa/lambda FLC ratio. * Participants received 1 to 3 prior lines of antimyeloma therapy. * Participants achieve…