A Study to Evaluate CC-92480, Bortezomib and Dexamethasone (480Vd) Versus Pomalidomide, Bortezomib and Dexamethasone (PVd) in Participants With Relapsed or Refractory Multiple Myeloma (RRMM)

Inclusion Criteria:

Participant has documented diagnosis of MM and measurable disease, defined as any of the following:

M-protein ≥ 0.5 grams per deciliter (g/dL) by serum protein electrophoresis (sPEP) or
M-protein ≥ 200 milligrams (mg) per 24-hour urine collection by urine protein electrophoresis (uPEP)
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 achieved minimal response [MR] or better to at least 1 prior antimyeloma therapy.

Exclusion Criteria:

Participant has had progression during treatment or within 60 days of the last dose of a proteasome inhibitor.
For participants with prior treatment of a bortezomib containing regimen, the best response achieved was not a minimal response (MR) or better, or participant discontinued bortezomib due to toxicity.
Participant has had prior treatment with CC-92480 or pomalidomide.

Other protocol-defined criteria apply.