ATRN-119

ATRN-119 is an orally bioavailable, potent, and highly selective first-in-class macrocyclic small molecule inhibitor of the DNA damage response (DDR) protein kinase ataxia telangiectasia and Rad3-related (ATR) kinase. It is designed to inhibit ATR, a key regulator of the cellular response to DNA damage, thereby disrupting cancer cell survival mechanisms—particularly in tumors with mutations in DDR-related genes such as BRCA1/2. This mechanism exploits synthetic lethality for antineoplastic activity and holds promise for patients with difficult-to-treat cancers that have poor prognosis due to DDR gene mutations. ATRN-119 is currently being evaluated in Phase 1/2 clinical trials for advanced solid tumors.