Genomic biomarkers predict response to combined ATR inhibition and radiotherapy

For decades, chemoradiosensitization with checkpoint kinase inhibitors has been proposed but largely unexplored. A recent study reports the novel ATR kinase inhibitor, RP-3500, synergizes with radiation to control Atm-/- tumors in vivo. RP-3500 did not radiosensitize wild-type or Brca-1 deficient tumors, highlighting the need for a genotype-tailored approach.