Nivolumab in Multiple Myeloma Patients After Idecabtagene Vicleucel

This study is testing whether adding a drug called nivolumab (an immune checkpoint inhibitor) after a CAR-T cell therapy called idecabtagene vicleucel (ide-cel) can help multiple myeloma patients maintain their response to treatment for longer. Ide-cel is an advanced cell therapy that reprograms the patient's own immune cells to fight myeloma. **You may be eligible if...** - You are 18 or older - You have multiple myeloma and recently received ide-cel (CAR-T) treatment according to approved guidelines - Your myeloma responded to ide-cel (partial response or better) - You are enrolling between 3 and 6 weeks after your ide-cel infusion - Your overall health status is good (ECOG 0–1) - Your organ function (blood, liver, kidneys) meets the required levels **You may NOT be eligible if...** - You have Waldenstrom's macroglobulinemia, POEMS syndrome, or amyloidosis - You have an active serious infection (including uncontrolled HIV, active hepatitis B or C, or active TB) - You are pregnant or breastfeeding - You currently have cytokine release syndrome or neurotoxicity - You have had a stem cell transplant (allogeneic) or solid organ transplant - You have active autoimmune disease requiring treatment or a history of severe lung inflammation - You have a history of myocarditis Talk to your doctor to see if this trial is right for you.