Phase 3 Study of Teclistamab in Combination With Lenalidomide and Teclistamab Alone Versus Lenalidomide Alone in Participants With Newly Diagnosed Multiple Myeloma as Maintenance Therapy Following Autologous Stem Cell Transplantation

Inclusion Criteria: * Must have a new diagnosis of multiple myeloma according to IMWG criteria and have received induction +/- consolidation. * Must have received only one line of therapy and achieved at least a partial response (≥PR) as per IMWG 2016 response criteria (Kumar 2016) without evidence of progression at the time of first treatment dose. * Must not be intolerant to the starting dose of lenalidomide. * Must not have received any maintenance therapy. * Have an ECOG performance status score of 0, 1, or 2 at screening and immediately prior to the start of administration of study treatment * Have clinical laboratory values within prespecified range. Exclusion Criteria: * Received any prior BCMA-directed therapy. * Any previous therapy with an immune cell redirecting agent or gene modified adoptive cell therapy (eg, chimeric antigen receptor modified T cells, NK cells). * Discontinued treatment due to any AE related to lenalidomide as determined by the investigator. * Progressed on multiple myeloma therapy at any time prior to screening. * Received a cumulative dose of corticosteroids equivalent to ≥140 mg of prednisone within the 14 days prior to first treatment dose. * Received a live, attenuated vaccine within 4 weeks before first treatment dose. Non-live vaccines or non-replicating authorized for emergency use (eg. COVID-19) are allowed.