A Study to Evaluate Mezigdomide, Bortezomib and Dexamethasone (MEZIVd) Versus Pomalidomide, Bortezomib and Dexamethasone (PVd) in Participants With Relapsed or Refractory Multiple Myeloma (RRMM)

Must have received: antimyeloma therapy

Participants achieved minimal response [MR] or better to at least 1 prior antimyeloma therapy.

Cannot have received: proteasome inhibitor

Exception: Subjects who progressed while being treated with, or within 60 days of last dose of bortezomib maintenance given once every 2 weeks (or less frequently) are not excluded. Participants who progressed while being treated with ixazomib monotherapy maintenance ≥ 6 months prior to the time of starting study treatment are not excluded.

Participant has had progression during treatment or within 60 days of the last dose of a proteasome inhibitor, except as noted below

Cannot have received: bortezomib-containing regimen (bortezomib)

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.

Cannot have received: (mezigdomide, pomalidomide)

Participant has had prior treatment with mezigdomide or pomalidomide.