A Study Evaluating the Safety, Pharmacokinetics, and Activity of the Combination of Cevostamab and Elranatamab in Participants With Relapsed or Refractory Multiple Myeloma (R/R MM)

Inclusion Criteria: * Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1 * Diagnosis of R/R MM per IMWG criteria * For female participants of childbearing potential: agreement to remain abstinent or use contraception * For male participants: agreement to remain abstinent or use a condom Exclusion Criteria: * Prior treatment with cevostamab or another agent targeting fragment crystallizable receptor-like 5 (FcRH5) * Prior treatment with elranatamab * Prior allogeneic stem cell transplantation (SCT) * Absolute plasma cell count exceeding 500 per milliliter (mL) or 5% of the peripheral blood white cells * Diagnosis of Waldenström macroglobulinemia or polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin changes (POEMS) syndrome * Participants with known history of amyloidosis * History of autoimmune disease * History of confirmed progressive multifocal leukoencephalopathy * Peripheral motor polyneuropathy of prespecified grade * Known or suspected chronic cytomegalovirus (CMV) and/or Epstein-Barr virus (EBV) infection * Known history of hemophagocytic lymphohistiocytosis (HLH) or macrophage activation syndrome (MAS) * Acute or chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection * Human immunodeficiency virus (HIV) seropositivity * History of central nervous system (CNS) myeloma disease * Significant cardiovascular disease