This study aims to find a safe dose of a new medicine called **BMS-986393** when used with other medicines in patients with **relapsed and/or refractory multiple myeloma (RRMM)**. Multiple myeloma is a type of blood cancer that affects plasma cells, which are a part of your immune system. "Relapsed" means the cancer has come back, and "refractory" means it didn't respond well to treatment.

Participants will receive BMS-986393 with other medicines: alnuctamab, mezigdomide, and iberdomide. To join, you should have RRMM treated with at least 1-3 treatments before. You need to be in good health, with a performance status of 0-1, which means you can carry out normal activities without assistance.

However, if you have any condition that makes it hard to understand the study results or have a history of multiple myeloma affecting your brain or spinal cord, you cannot join. There are more rules about who can join, which are not listed here.

• The study involves trying new drug combinations.
• Participants should have undergone previous treatments.
• Good health condition is required for participation.