Pharmacokinetic assessment
After cocktail alone (day − 8) and with adavosertib co-administration (period 2 day 3), 24-h venous blood sampling took place for PK measurements of caffeine, omeprazole, midazolamAUC from time zero to 12 h (AUCPlasma concentrations for caffeine, paraxanthine, omeprazole, 5-HO, midazolam, and 1ʹ­HM were all determined by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) at Labcorp Bioanalytical Laboratories (Madison, WI, USA).Plasma concentrations of caffeine and paraxanthine collected with KPlasma concentrations of omeprazole and 5-HO were collected with lithium heparin as anticoagulant and were determined by HPLC–MS/MS detection simultaneously. The standard curves of omeprazole and 5-HO both ranged from 20.0 to 20,000 nmol/L. Precision (%CV) and accuracy (percentage bias) for the QC samples were ≤ 3.9% and ≤ 4.4% CV and within 0.0 − 9.0% and − 1.9% to 2.2% bias for omeprazole and 5-HO, respectively. The LLOQ was 20.0 nM for omeprazole and 5-HO.Plasma concentrations of midazolam and 1ʹ-HM were collected with KThe concentration of adavosertib in human plasma was determined by Labcorp Bioanalytical Laboratories using the same validated method described previously [All plasma samples were stored at − 70 °C (or below) prior to analysis and analyzed within the validated time frame.