Obrixtamig — Investigational Agent
T-Cell Engager · Phase 2 · Boehringer Ingelheim
Mechanism of Action
Obrixtamig (BI 764532) is a DLL3 x CD3 bispecific T-cell engager. Delta-like ligand 3 (DLL3) is an inhibitory Notch ligand aberrantly expressed on the cell surface of high-grade neuroendocrine carcinomas, including GI/extrapulmonary neuroendocrine carcinomas, but minimally on normal tissue. One arm binds DLL3 on tumor cells while the CD3 arm engages T lymphocytes, forming a cytolytic synapse that triggers polyclonal T-cell activation and MHC-independent tumor cell killing. This redirects the patient's own T cells against DLL3-positive neuroendocrine tumors regardless of prior antigen exposure.
Investigational Indications
- DLL3-positive gastrointestinal/extrapulmonary neuroendocrine carcinoma
- Neuroendocrine carcinomas
- Small cell lung cancer