A Study to Learn About the Study Medicine (Elranatamab) in Participants With Multiple Myeloma That Has Come Back After Responding to Treatment or Has Not Responded to Treatment

Inclusion Criteria

• Diagnosis of multiple myeloma (IMWG criteria, Rajkumar et al, 2014)
• Measurable disease, as defined by at least 1 of the following:
• Serum M-protein >0.5 g/dL by SPEP
• Urinary M-protein excretion >200 mg/24 hours by UPEP
• Serum immunoglobulin FLC≥10 mg/dL (≥100 mg/L) AND abnormal serum immunoglobulin kappa to lambda FLC ratio
• Refractory to at least one IMiD
• Refractory to at least one PI
• Refractory to at least one anti-CD38 antibody
• Relapsed/refractory to last anti-myeloma regimen
• ECOG performance status ≤1
• Resolved acute effects of any prior therapy to baseline severity or CTCAE Grade ≤1
• Not pregnant and willing to use contraception

Exclusion Criteria

• Smoldering multiple myeloma
• Active Plasma cell leukemia
• POEMS syndrome
• Amyloidosis
• Waldenström's macroglobulinemia
• Known active CNS involvement or clinical signs of myelomatous meningeal involvement
• Stem cell transplant within 12 weeks prior to enrollment or active GVHD
• Active HBV, HCV, SARS-CoV2, HIV, or any active, uncontrolled bacterial, fungal, or viral infection
• Any other active malignancy within 3 years prior to enrollment, except for adequately treated basal cell or squamous cell skin cancer, or carcinoma in situ or Stage 0/1 malignancy with minimal risk of recurrence per investigator.
• Previous treatment with an anti-BCMA bispecific antibody or CAR-T cell therapy.
• Live attenuated vaccine within 4 weeks of the first dose
• Previous administration with an investigational drug within 30 days or 5 half-lives preceding the first dose of study intervention used in this study (whichever is longer)
• Known or suspected hypersensitivity to the study intervention, or any of its excipients