Mezigdomide and Talquetamab in Relapsed and Refractory Multiple Myeloma

Inclusion Criteria: * Participant has given voluntary signed written informed consent before performance of any study-related procedure that is not part of normal medical care, with the understanding that consent may be withdrawn by the participant at any time without prejudice to their future medical care. * Eastern Cooperative Oncology Group (ECOG) performance status ≤2 (see Appendix). * Age ≥ 18 years * Measurable disease of multiple myeloma as defined by at least one of the following: * Serum monoclonal protein ≥ 0.5 g/dL. Patients with IgD disease and lower amounts of monoclonal protein may be permitted to enroll with PI approval * ≥ 200 mg of monoclonal protein in the urine on 24-hour urine protein electrophoresis * Serum free light chain (FLC) ≥ 100 mg/L (10 mg/dL) and abnormal serum free light chain ratio * Previously treated relapsed and refractory multiple myeloma: * Patients must have received at least three prior lines of therapy; * Prior therapy including an immunomodulatory drug, proteasome inhibitor, and anti-CD38 antibody (either in separate regimens or within the same regimen); and * Disease progression on, or within 60 days of completion of last therapy. * ANC ≥ 1000/μL. G-CSF is not permitted within 14 days of screening. * Platelet count ≥ 50,000/µL. Platelet transfusion and thrombopoietin receptor agonists are not permitted within 7 days of screening. * Hemoglobin ≥ 8 g/dL. Red blood cell transfusions are permitted to meet eligibility criter…