ATRC-301

ATRC-301 is a preclinical antibody-drug conjugate (ADC) oncology candidate developed by Atreca that targets a novel, membrane-proximal epitope on ephrin type-A receptor 2 (EphA2), a receptor tyrosine kinase overexpressed in multiple solid tumors including breast, colorectal, ovarian, non-small cell lung cancer, and melanoma.[1][9][10][14] The construct uses an Atreca-discovered anti-EphA2 antibody conjugated via Zymeworks’ ZymeLink platform to undisclosed cytotoxic payload and linker chemistry, and is designed to deliver a tubulin-inhibiting cytotoxin selectively to EphA2-positive tumor cells, thereby blocking EphA2 signaling and inducing mitotic arrest and apoptosis.[1][5][9][10] ATRC-301 remained in IND-enabling, preclinical development when non-human primate toxicity studies revealed bleeding safety signals consistent with historical EphA2-targeting ADC toxicities, leading to discontinuation of the program before clinical testing.[2][3][6][13]