Iberdomide Versus Observation Off Therapy After Idecabtagene Vicleucel CAR-T for Multiple Myeloma

This study is being done to answer the following questions: 1) Can the study drug iberdomide be given after idecabtagene vicleucel (ide-cel (Abecma)) CAR-T in multiple myeloma safely and with acceptably few and mild side effects? 2) For how long does multiple myeloma stay under control (in remission) if patients receive the study drug iberdomide after they have received ide-cel (Abecma) CAR-T? We are doing this study because we want to find out if this approach is better or worse than the usual approach for your multiple myeloma. The usual approach is defined as care most people get for multiple myeloma.