CD3 x FLT3

Class

Bispecific T-cell engager (DuoBody)

Notes

Source: https://clinicaltrials.gov/study/NCT07384715 ; corroborating press 2026 (GEN3018; Genmab pipeline page 403'd at research time — researched 2026-08-08)

CD3 x FLT3 describes a bispecific antibody engineered to bind two different targets simultaneously: CD3, a signaling component of the T-cell receptor complex present on essentially all T lymphocytes, and FLT3 (FMS-like tyrosine kinase 3), a cell-surface receptor highly expressed on the malignant blasts of acute myeloid leukemia (AML) and, in a subset of patients, mutated to drive uncontrolled proliferation. By physically linking a T cell to a FLT3-expressing leukemic cell, this molecule forms an artificial immune synapse that activates the T cell independent of its native antigen specificity, triggering release of cytotoxic granules that kill the bound tumor cell. This approach, generally termed a T-cell engager, exploits the immune system's killing machinery rather than relying on a drug's intrinsic chemical activity against the cancer cell. The rationale for targeting FLT3 specifically is that it is broadly and consistently displayed on AML blasts, making it a reliable handle for redirecting immune attack even in patients whose disease is genetically heterogeneous. This class of mechanism is relevant across hematologic malignancies where a tumor-associated surface antigen can be paired with CD3 to recruit cytotoxic T cells directly to disease sites, offering an alternative to conventional chemotherapy or kinase inhibition.