This Phase II, open-label, multicenter study will evaluate teclistamab in combination with pomalidomide administered using an alternative dosing approach in participants with relapsed or refractory multiple myeloma who have received 1-3 prior lines of therapy, including lenalidomide and anti-CD38 therapy. Teclistamab is a bispecific antibody that targets BCMA on myeloma cells and CD3 on T cells, bringing these cells into close proximity and activating T cells to induce targeted killing of BCMA-expressing myeloma cells. The study will assess the safety and efficacy of this treatment combination in participants with relapsed or refractory multiple myeloma.