A Phase 1, Multicenter, Open-label Study to Evaluate the Safety and Preliminary Efficacy of BMS-986393 in Novel Combinations in Participants with Relapsed and/or RefractoryMultiple Myeloma and Determine the Recommended Dose for Each Add-on Investigational

The purpose of this study is to test whether BMS-986393 in combination with other anti- cancer drugs is safe and effective at treating people with multiple myeloma (MM) that has come back after previous treatment (relapsed) or is not responding to current treatment (refractory). The researchers think that the combinations of alnuctamab, mezigdomide, or iberdomide with BMS-986393 in people with relapsed/refractory MM may improve their disease or keep their disease under control. This is an open-label, multicenter study that will recruit potential participants in the United States (USA) and Canada. This study consists of two parts: dose finding (Part 1) and dose expansion (Part 2), and will treat participants in three different treatment groups, called Arms. Participants will receive a different combination of treatments in each Arm. These combinations are considered investigational, which means they are not approved for your disease by the Food and Drug Administration (FDA).

Are you Eligible? (Inclusion Criteria)

• Participant has a diagnosis of MM with relapsed and/or refractory disease - Participant must be 18 years of age or older at the time of signing the ICF - Participants may have received at least 3 prior anti-myeloma treatment regimens