IHC
PD, tumor, Tumor
TUMOR, TUMOR
Tumor biopsies were collected from patients at baseline and on cycle 2, day 10 between 8 h and 24 h after dosing. Distal PD markers, pKAP1 and gH2AX, were then assessed by tumor IHC centrally at HistoWiz, Inc. Although CHK1 phosphorylation (p-CHK1) is a more direct and proximal biomarker of ATR inhibition, preclinical studies have demonstrated that p-CHK1 declines rapidly after dosing