RecruitingPhase 2Biological interventionA Study of Elranatamab and Cyclophosphamide in People With Multiple MyelomaThe purpose of this study is to find out whether the combination of elranatamab and cyclophosphamide is an effective treatment for people with relapsed/refractory multiple myeloma (MM) who have risk factors that may affect how well their disease would respond to elranatamab alone.