HLX3901

HLX3901 is a next-generation, tetra-specific T-cell engager (TCE) developed by Shanghai Henlius Biotech for the treatment of advanced small cell lung cancer (SCLC) and neuroendocrine carcinoma (NEC). Engineered using a proprietary TCE platform and AI-driven molecular design, HLX3901 targets two distinct epitopes on Delta-like protein 3 (DLL3) while simultaneously engaging the T-cell receptors CD3 (Signal 1) and CD28 (Signal 2). This dual-signal activation is designed to enhance T-cell cytotoxicity, activation, proliferation, and persistence against DLL3-expressing tumors, particularly in the tumor microenvironment (TME) where low tumor-infiltrating lymphocyte (TIL) density often limits the efficacy of traditional bispecific antibodies. By incorporating CD28 co-stimulation, HLX3901 aims to achieve sustained anti-tumor activity while potentially reducing the risk of cytokine release syndrome (CRS).