Drugging ATR: progress in the development of specific inhibitors for the treatment of cancer

In this article, we review the ATR inhibitor field from initial pharmacological tools to first-generation clinical candidates with the potential to bring benefit to cancer patients. ATR is a critical part of the cell DNA-damage response. Over the past decade or more, compounds with weak ATR potency and low specificity have been used as tools in early studies to elucidate ATR pharmacology. More recently highly potent, selective and in vivo active ATR inhibitors have been developed enabling detailed preclinical in vitro and in vivo target assessment to be made. The published studies reveal the potential of ATR inhibitors for use as monotherapy or in combination with DNA-damaging agents. To date, VX-970 and AZD6738, have entered clinical assessment.