RecruitingPhase 1Drug trialMezigdomide and Talquetamab in Relapsed and Refractory Multiple MyelomaThis is a phase 1 study to find the recommended dose and schedule of mezigdomide and talquetamab in relapsed and refractory multiple myeloma (RRMM), and to test the effects of the drugs on cancer. Cohort A will receive talquetamab + dexamethasone, then mezigdomide + talquetamab,+ dexamethasone. After Cohort A, Cohort B will evaluate mezigdomide + dexamethasone followed by step-up dosing of talquetamab (mezigdomide + talquetamab,+ dexamethasone).