FID-031

FID-031 is a novel antibody-drug conjugate (ADC) targeting the human epidermal growth factor receptor 2 (HER2), developed by Fulgent Pharma. It consists of a HER2-targeting antibody conjugated to a topoisomerase I inhibitor payload via a proprietary stable hydrophilic linker, with an estimated drug-to-antibody ratio (DAR) of 7. In preclinical studies, FID-031 demonstrated superior and more sustained tumor growth inhibition compared to trastuzumab deruxtecan (T-DXd) across various HER2-high and HER2-low cancer models. The drug exhibits improved pharmacokinetics, deeper tumor penetration, and a favorable safety profile with lower free payload accumulation in the intestines compared to T-DXd. Preclinical toxicology studies in non-human primates are currently in progress.