QBH-196

QBH-196 is an orally bioavailable, small molecule inhibitor of the Ataxia Telangiectasia and Rad3-related (ATR) kinase, developed by China Resources Sanjiu Medical & Pharmaceutical. ATR is a critical sensor in the DNA damage response (DDR) system, activated by replication stress and single-strand breaks. Inhibition of ATR prevents the stabilization of replication forks and the activation of the S and G2/M checkpoints, forcing cells with damaged DNA into premature mitosis and subsequent cell death. This mechanism is particularly effective in tumors with existing defects in other DDR pathways, such as ATM or p53 mutations, through the principle of synthetic lethality. QBH-196 is currently in Phase 1 clinical trials for patients with advanced solid tumors.