HEC-921

HEC-921 is a first-in-class fully human bispecific antibody targeting lymphocyte antigen 6 family member G6D (LY6G6D) and tumor necrosis factor receptor superfamily member 9 (4-1BB / CD137). Developed by Sunshine Lake Pharma (HEC Pharm), HEC-921 is designed for tumor-targeted immune activation. It utilizes LY6G6D as a tumor-specific anchor to selectively enrich within tumor tissues, particularly in DNA mismatch repair proficient (pMMR) colorectal cancers and other LY6G6D-positive solid tumors. Simultaneously, it activates the 4-1BB pathway locally within the tumor microenvironment, minimizing systemic toxicities such as hepatotoxicity that are historically associated with systemic 4-1BB agonists.