A Study Evaluating the Safety, Pharmacokinetics, and Activity of Cevostamab in Participants With Relapsed or Refractory Multiple Myeloma

This Phase Ib, multicenter, open-label study will evaluate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of cevostamab monotherapy, cevostamab plus pomalidomide and dexamethasone (Pd) or cevostamab plus daratumumab and dexamethasone (Dd) which will be administered to participants with relapsed or refractory multiple myeloma (R/R MM) via intravenous (IV) infusion.

Inclusion Criteria: * Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1 * Life expectancy of at least 12 weeks * Agreement to provide bone marrow biopsy and aspirate samples * Resolution of adverse events from prior anti-cancer therapy to Grade \= 3 CRS or immune effector cell-associated neurotoxicity syndrome (ICANS) with prior bispecific therapies * Known history of hemophagocytic lymphohistiocytosis (HLH) or immune effector cell associated hemophagocytic lymphohistiocytosis like syndrome (IEC HS) * Active symptomatic coronavirus disease 2019 (COVID-19) infection at study enrollment or requiring treatment with intravenous (IV) antiviral where the last dose of IV antiviral treatment was given within 14 days prior to first study treatment. Patients with active COVID-19 infection must have clinical recovery and two negative antigen tests at least 24 hours apart prior to first study treatment * Positive and quantifiable EBV polymerase chain reaction (PCR) or Cytomegalovirus (CMV) PCR prior to first study treatment * Known history of HIV seropositivity * Administration of a live, attenuated vaccine within 4 weeks before first study treatment or anticipation that such a live attenuated vaccine will be required during the study * Treatment with systemic immunosuppressive medications, with the exception of corticosteroid treatment \