MagnetisMM-3: Study Of Elranatamab (PF-06863135) Monotherapy in Participants With Multiple Myeloma Who Are Refractory to at Least One PI, One IMiD and One Anti-CD38 mAb

The purpose of the study is to evaluate whether single-agent Elranatamab (PF-06863135) can provide clinical benefit in participants with relapsed/refractory multiple myeloma. Elranatamab is a bispecific antibody: binding of Elranatamab to CD3-expressing T-cells and BCMA-expressing multiple myeloma cells causes targeted T-cell-mediated cytotoxicity.

Inclusion Criteria: * Diagnosis of multiple myeloma (IMWG criteria, Rajkumar et al, 2014) * Measurable disease, as defined by at least 1 of the following: 1. Serum M-protein \>0.5 g/dL by SPEP 2. Urinary M-protein excretion \>200 mg/24 hours by UPEP 3. 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 * Cohort A: has not received prior BCMA-directed therapy * Cohort B: has received prior BCMA-directed therapy (ADC or CAR T cells) * ECOG performance status ≤2 * 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 * Amyloidosis * POEMS syndrome * Stem cell transplant within 12 weeks prior to enrollment * 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. * 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)