Stevo: This Phase I trial is evaluating how safe and tolerable a targeted therapy (cevostamab) is in people with relapsed or refractory multiple myelomoaAn Open-Label, Multicenter, Phase Ib Trial Evaluating the Safety, Pharmacokinetics, and Activity of Cevostamab in Patients With Relapsed or Refractory Multiple Myeloma

Exclusion

• Prior treatment with cevostamab or another agent targeting FcRH5
• Inability to comply with protocol-mandated hospitalization and activities restrictions
• Pregnant or breastfeeding, or intending to become pregnant during the study or within 5 months after the last dose of cevostamab or within 3 months after the last dose of tocilizumab (if applicable).
• Prior use of any monoclonal antibody, radioimmunoconjugate, or antibody-drugconjugate as anti-cancer therapy within 4 weeks before first study treatment, except for the use of non-myeloma therapy
• Prior treatment with systemic immunotherapeutic agents, including, but not limited to, cytokine therapy and anti-CTLA4, anti-PD-1, and antiPD-L1 therapeutic antibodies within 12 weeks or 5 half-lives of the drug, whichever is shorter, before first study treatment
• Prior treatment with chimeric antigen receptor T (CAR T)-cell therapy within 12 weeks before first study treatment
• Treatment with radiotherapy within 4 weeks (systemic radiation) or 14 days (focal radiation) prior to first study treatment
• Treatment with any chemotherapeutic agent or other anti-cancer agent (investigational or otherwise) within 4 weeks or 5 half-lives of the drug, whichever is shorter, prior to first study treatment
• Autologous SCT within 100 days prior to first study treatment
• Prior allogeneic stem cell transplant(ation) (SCT)
• Circulating plasma cell count exceeding 500/micro L or 5% of the peripheral blood white cells
• Prior solid organ transplantation
• History of autoimmune disease
• History of confirmed progressive multifocal leukoencephalopathy
• History of severe allergic or anaphylactic reactions to monoclonal antibody therapy
• Known history of amyloidosis
• Lesions in proximity of vital organs that may develop sudden decompensation/deterioration in the setting of a tumor flare
• History of other malignancy within 2 years prior to screening
• Known treatment-related, immune-mediated adverse events associated with prior checkpoint inhibitors
• Current or past history of central nervous system (CNS) disease, such as stroke, epilepsy, CNS vasculitis, neurodegenerative disease, or CNS involvement by MM
• Significant cardiovascular disease
• Symptomatic active pulmonary disease or requiring supplemental oxygen
• Known active bacterial, viral, fungal, mycobacterial, parasitic, or other infection
• Known or suspected chronic active Epstein-Barr virus (EBV) infection
• Recent major surgery within 4 weeks prior to first study treatment
• Positive serologic or PCR test results for acute or chronic hepatitis B virus (HBV) infection
• Acute or chronic hepatitis C virus (HCV) infection
• Known history of Grade >= 3 CRS or immune effector cell-associated neurotoxicity syndrome (ICANS) with prior bispecific therapies
• Known history of hemophagocytic lymphohistiocytosis (HLH) or macrophage activation syndrome (MAS)
• 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 <=10 mg/day prednisone or equivalent, within 2 weeks prior to first study treatment
• History of illicit drug or alcohol abuse within 12 months prior to screening, in the investigator's judgment Additional Arm B-Specific Exclusion Criteria
• Pregnant or breastfeeding, or intending to become pregnant 4 weeks prior to initiation of study treatment, during the study, (including treatment interruptions) or within 4 weeks after the last dose of pomalidomide
• Significant cardiovascular disease (such as, but not limited to, New York Heart Association Class III or IV cardiac disease, myocardial infarction within the last 12 months, uncontrolled arrhythmias, or unstable angina)
• History of erythema multiforme, Grade >=3 rash, blistering, or severe hypersensitivity to prior treatment with immunomodulatory drugs such as thalidomide, lenalidomide, or pomalidomide
• Inability to tolerate thromboprophylaxis, or contraindication to thromboprophylaxis
• GI disease that might significantly alter absorption of oral drugs Additional Arm C-Specific Exclusion Criteria
• Pregnant or breastfeeding, or intending to become pregnant during the study or within 102 days after the last dose of daratumumab
• Known hypersensitivity to biopharmaceuticals produced in CHO cells or any component of daratumumab formulations
• Known chronic obstructive pulmonary disease (COPD) with a forced expiratory volume in 1 second (FEV1) <50% of predicted normal
• Known moderate or severe persistent asthma within the past 2 years, or current uncontrolled asthma of any classification