Our most advanced internal candidate is ARX788, an anti-HER2 ADC currently being studied broadly in breast cancer, gastric/GEJ cancer and other solid tumor clinical trials. The United States Food and Drug Administration (FDA) has granted Fast Track Designation for ARX788 in HER2+ metastatic breast cancer and Orphan Drug Designation for ARX788 in gastric cancer.
ARX788 is a homogeneous and highly stable ADC, which targets the HER2 receptor and contains two AS269 cytotoxic payloads site-specifically conjugated to a trastuzumab-based antibody. ARX788 was designed to maximize potential anti-tumor activity by optimizing the number and position of the payloads and the chemical bonds that conjugate the payloads to the antibody. AS269, our proprietary payload, is a tubulin inhibitor specifically designed to form a highly stable covalent bond with our SAAs and kill tumor cells only upon entry into the cell when aided by the conjugated targeting antibody, thereby limiting off-target effects on healthy tissue.