LM-338

LM-338 is an innovative antibody-drug conjugate (ADC) targeting the Sialyl-Thomsen-nouveau (STn) antigen, a truncated O-glycan overexpressed in various carcinomas but with limited expression in normal tissues. Developed by LaNova Medicines, LM-338 consists of a humanized monoclonal antibody (LM-138) conjugated to a topoisomerase I inhibitor payload via a cleavable linker, maintaining a drug-antibody ratio (DAR) of 4. In preclinical studies, LM-338 demonstrated high binding specificity to STn and potent anti-tumor activity across multiple solid tumor models, including ovarian, colorectal, and lung cancers, while showing a favorable safety profile in non-human primates. The agent is designed to deliver its cytotoxic payload directly to STn-expressing tumor cells, inducing DNA damage and cell death while minimizing off-target toxicity.