MagnetisMM-5: An open-label, 3-arm, multicenter, randomized Phase 3 study to evaluate the efficacy and safety of elranatamab (PF-06863135) monotherapy and elranatamab + daratumumab versus daratumumab + pomalidomide + dexamethasone in participants with relapsed/refractory multiple myeloma who have received at least 1 prior line of therapy including lenalidomide and a proteasome inhibitor