Ataxia telangiectasia and Rad3-related inhibitors and cancer therapy: where we stand

BACKGROUND: The ataxia telangiectasia and Rad3-related (ATR) checkpoint kinase 1 (CHK1) pathway plays an essential role in suppressing replication stress from DNA damage and oncogene activation. MAIN BODY: Preclinical studies have shown that cancer cells with defective DNA repair mechanisms or cell cycle checkpoints may be particularly sensitive to ATR inhibitors. Preclinical and clinical data from early-phase trials on three ATR inhibitors (M6620, AZD6738, and BAY1895344), either as monotherapy or in combination, were reviewed. CONCLUSION: Data from ATR inhibitor-based combinational trials might lead to future expansion of this therapy to homologous recombination repair pathway-proficient cancers and potentially serve as a rescue therapy for patients who have progressed through poly ADP-ribose polymerase inhibitors.