Effect of Multiple Doses of Omeprazole on the Pharmacokinetics, Safety, and Tolerability of Roxadustat in Healthy Subjects

BACKGROUND AND OBJECTIVES: Roxadustat is an orally active hypoxia-inducible factor prolyl hydroxylase inhibitor for the treatment of anemia in chronic kidney disease. This study investigated the effect of multiple daily oral doses of omeprazole on the pharmacokinetics, safety, and tolerability of a single oral dose of roxadustat. METHODS: This phase 1, open-label, two-period, one-sequence, crossover study enrolled healthy subjects. During Period 1, subjects received a single oral dose of 100 mg roxadustat. After a ≥ 7-day washout, subjects started Period 2 and received daily oral doses of 40 mg omeprazole on Days 1–9, and a single oral dose of 100 mg roxadustat on Day 7. Roxadustat pharmacokinetics were assessed on Days 1–4 in Period 1 and on Days 7–10 in Period 2. Primary endpoints were area under the concentration–time profile from the time of dosing extrapolated to infinity (AUC(inf)) and maximum concentration (C(max)). Safety was assessed by vital signs, laboratory tests, electrocardiograms, and nature, frequency, and severity of treatment-emergent adverse events (TEAEs). RESULTS: Eighteen subjects were enrolled. The geometric least squares mean ratio for both AUC(inf) and C(max) of roxadustat (with omeprazole/alone) was 104.5%; 90% confidence intervals were within the no-effect boundaries of 80.0 and 125.0%, indicating no significant effect of omeprazole on the pharmacokinetics of roxadustat. No serious TEAEs were reported. CONCLUSION: Multiple daily oral doses of 40 mg omeprazole had no significant effect on the pharmacokinetics of a single oral dose of 100 mg roxadustat. Roxadustat was considered safe and well tolerated when administered alone or in combination with multiple daily oral doses of 40 mg omeprazole in healthy subjects. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13318-018-0480-z) contains supplementary material, which is available to authorized users.