Study Overview: This study is testing a new treatment called arlo-cel (BMS-986393) to see if it's better and safer than usual treatments for adults who have a type of blood cancer called Multiple Myeloma. Multiple Myeloma is a cancer of the plasma cells, a type of white blood cell found in bone marrow. The study is for people whose cancer has returned or didn't respond to initial treatments and have already taken a drug called Lenalidomide.

Eligibility: To join, participants must have a confirmed diagnosis of Relapsed or Refractory Multiple Myeloma (RRMM), which means the cancer has either come back or isn’t responding to treatment. They've tried 1 to 3 different treatments before, and should have good organ function and an active disease that can be measured. They can't have involvement of the central nervous system by the cancer or need immediate treatment due to fast cancer growth.

• The study compares a new treatment to standard ones.
• Participants need to have tried specific cancer treatments before.
• People with fast-growing or brain-involved cancer cannot join.