RecruitingPhase 2Drug trialA Phase 2 Study of Radiotherapy-induced Immune Priming to Enhance Elranatamab (Elra) in Relapsed Refractory Multiple Myeloma (RRMM) With Extramedullary Disease (EMD) and Paramedullary Disease (PMD) "PRIME-EMD-PMD"To learn if low doses of radiation therapy can help the drug elranatamab enhance the killing effect of the cancer cells.