HA-00495

HA-00495 is a preclinical-stage antibody-drug conjugate (ADC) developed by Hexagon Bio. It consists of the anti-HER2 monoclonal antibody trastuzumab conjugated to a novel protein translation inhibitor payload identified through Hexagon's natural product discovery platform. This payload features a mechanism of action that is non-overlapping with traditional ADC payload classes, such as topoisomerase and microtubule inhibitors, potentially overcoming resistance to existing therapies. In preclinical studies, HA-00495 has demonstrated deep and durable antitumor activity in HER2-expressing models of breast, gastric, lung, and bladder cancers, including those with known resistance to topoisomerase inhibitor-based ADCs. Safety evaluations in non-human primates (NHPs) have shown an acceptable tolerability profile, supporting its continued development as a candidate for HER2-positive malignancies.