**Study Overview:** This research is for people with *relapsed* or *refractory multiple myeloma* (RRMM). Multiple myeloma is a type of blood cancer that affects plasma cells in the bone marrow. *Relapsed* means the cancer has returned after treatment, and *refractory* means the cancer didn’t respond to treatment. The study aims to find a safe dose of a new drug, BMS-986393, combined with other medicines (alnuctamab, mezigdomide, and iberdomide) for treating RRMM. **Key Points:** - **Duration & Visits:** Participation may require multiple visits to the study site over a period of time, although exact details are not specified. - **Eligibility:** You must have been treated with at least one prior anti-myeloma treatment and have measurable multiple myeloma. - **Risks & Benefits:** While this study may offer potential benefits, such as disease management, it may also involve risks like side effects from the new drug combinations. Before considering participation, discuss with your doctor to understand the potential effects on your health. Always consider both the benefits and risks when deciding on joining a clinical trial.