Bispecific T-cell Engagers in Hematologic Malignancies

Bispecific T-cell Engagers in Hematologic Malignancies

Bispecific T-cell engagers redirect the immune system against blood cancers. These antibodies bind a tumor antigen on one arm and CD3 on T cells on the other arm. The linkage forces T cells to kill malignant cells. As a result, the approach bypasses the need for prior antigen presentation or engineered cell manufacturing.

Blinatumomab was the first approved agent of this class. It targets CD19 and CD3 and is used in B-cell acute lymphoblastic leukemia. Later approvals expanded the platform to other diseases. In B-cell lymphomas, CD20-directed bispecifics such as epcoritamab, glofitamab, and mosunetuzumab produce meaningful responses in relapsed or refractory patients. In multiple myeloma, several agents are now available. Teclistamab, elranatamab, and linvoseltamab target BCMA, while talquetamab targets GPRC5D. These drugs have shown high response rates in heavily pretreated patients.

Compared with CAR-T therapy, bispecific engagers are available off the shelf. Patients can begin treatment without the delay of cell collection and manufacturing. However, they require repeated dosing and careful monitoring. Cytokine release syndrome and immune effector cell–associated neurotoxicity remain the main acute risks. Step-up dosing schedules and premedication help reduce the severity of these events. Infection risk also rises because of prolonged B-cell or plasma-cell depletion. Therefore, antimicrobial prophylaxis and close follow-up are essential.

Clinical use is moving earlier. Trials are testing bispecifics in combination with other agents and in frontline settings for myeloma and lymphoma. Some studies explore sequential use after CAR-T or in patients who progress on one target. Switching between BCMA- and GPRC5D-directed agents can still produce responses when antigen loss occurs. Consequently, the platform offers flexibility that cell therapies alone cannot always match.

Bispecific T-cell engagers have transformed options for patients with relapsed hematologic malignancies. Their off-the-shelf availability, high response rates, and expanding indications make them a central part of modern care. Ongoing trials will clarify optimal sequencing, combinations, and earlier use. When managed with attention to toxicity, these agents continue to improve outcomes for patients who previously had limited choices.