Pharmacokinetic effects of proton pump inhibitors on the novel PARP inhibitor fluzoparib: a single-arm, fixed-sequence trial in male healthy volunteers

Purpose To assess the pharmacokinetic (PK) effect of proton pump inhibitors on the novel poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitor fluzoparib, and observe the safety of its co-administration with omeprazole. Patients and methods Sixteen male healthy volunteers (HVs) were enrolled in a single-center, single-arm, open-label, fixed-sequence study. HVs took fluzoparib (100 mg, p.o.) after meal consumption on day-1, took omeprazole 40 mg (p.o.) under a fasting condition from day-5 to day-9, and took fluzoparib (100 mg, p.o.) after meal consumption on day-9. Blood samples were collected at predetermined timepoints for PK analyses. Safety was assessed via clinical laboratory tests. The study was registered with the Clinical Trials Registry on 30 September 2019 (NCT04108676). Results The peak plasma concentrations (C_max) after fluzoparib administration was 2395.17 ± 418.27 ng/mL, the area under the curve (AUC) within 72 h (AUC_{0 − 72 h}) was 26669.09 ± 7320.12 h·ng/mL, and AUC_0−∞ was 26897.44 ± 7573.61 h·ng/mL. The C_max after co-administration of fluzoparib and omeprazole was 2489.43 ± 423.72 ng·mL, AUC_{0 − 72 h} was 30300.49 ± 8350.08 h·ng/mL, and AUC_0−∞ was 30678.74 ± 8595.55 h·ng/mL. The geometric mean ratio of C_max, AUC_{0 − 72 h} and AUC_0−∞ was 104.0% (90%CI: 94.8–114.0%), 113.6% (104.2–123.9%) and 104.1% (104.5–124.6%). The number of HVs with adverse reactions was identical (eight) for administration of fluzoparib and co-administration of fluzoparib and omeprazole. Conclusions The proton pump inhibitor omeprazole did not have a significant influence on the PK behavior of fluzoparib, and its safety profile was good upon co-administration with omeprazole. (NCT04108676, 30 September 2019)