Refractory Plasmablastic Lymphoma

This phase Ib trial tests the safety, side effects, and best dose, as well as the effectiveness of teclistamab in treating patients with plasmablastic lymphoma that has come back after a period of improvement (recurrent) or that has not responded to previous treatment (refractory). Teclistamab is a bispecific antibody that can bind to two different antigens at the same time. Teclistamab binds to B-cell maturation antigen (BCMA), a protein found on some B-cells and myeloma cells, and CD3 on T-cells (a type of white blood cell) and may interfere with the ability of cancer cells to grow and spread. Giving teclistamab may be safe, tolerable, and/or more effective than usual treatment with radiation or chemotherapy in treating patients with recurrent or refractory plasmablastic lymphoma.