FXS887

FXS887 is an innovative small molecule inhibitor of the **ataxia telangiectasia and Rad3-related (ATR) protein kinase**, currently under development by **Fosun Pharma** (Shanghai Fosun Pharmaceutical Industrial Development Co. Ltd.). ATR is a key serine/threonine-protein kinase that orchestrates the cellular response to DNA replication stress and DNA damage. By selectively inhibiting ATR, FXS887 disrupts the DNA damage response (DDR) pathway, preventing cancer cells from repairing genomic lesions and leading to cell death through replication catastrophe. This mechanism is particularly effective in tumors with existing deficiencies in other DDR components, such as ATM or p53, via synthetic lethality. FXS887 is currently being evaluated in Phase 1 clinical trials for the treatment of advanced solid tumors that have proven refractory to conventional therapies.