Effects of Ketoconazole and Rifampicin on the Pharmacokinetics of Nintedanib in Healthy Subjects.

Background: Nintedanib is a substrate for p-glycoprotein which can impact bioavailability. We investigated the effects of ketoconazole, a p-glycoprotein inhibitor, and rifampicin, a p-glycoprotein inducer, on the pharmacokinetics of nintedanib.

Methods: In the ketoconazole study, 34 healthy subjects received nintedanib 50 mg orally alone and 1 h after the last dose of ketoconazole given orally at a dose of 400 mg once daily for 3 days in 1 of 2 randomized sequences. In the rifampicin study, 26 subjects received nintedanib 150 mg orally alone and the morning after the last dose of rifampicin given orally at a dose of 600 mg once daily for 7 days. The primary objective was to determine the relative bioavailability of nintedanib administered following multiple doses of ketoconazole or rifampicin versus alone, based on AUC from time 0 extrapolated to infinity (AUC) and maximum concentration (C) calculated using an analysis of variance. Geometric mean ratios and 2-sided 90% CIs were calculated.

Results: Exposure to nintedanib increased when it was administered following ketoconazole versus alone (AUC: geometric mean ratio, 160.5% [90% CI, 148.2-173.7]; C: geometric mean ratio, 179.6% [90% CI, 157.6-204.8]) and decreased when it was administered following rifampicin versus alone (AUC: geometric mean ratio, 50.1% [90% CI, 47.2-53.3]; C: geometric mean ratio, 59.8% [90% CI, 53.8-66.4]). The time to reach C (t) and half-life (t) of nintedanib were unaffected by co-administration of ketoconazole or rifampicin.

Conclusions: Exposure to nintedanib is increased by co-administration of ketoconazole and decreased by co-administration of rifampicin, likely due to effects on bioavailability of the absorbed fraction. ClinicalTrials.govidentifiers:NCT01679613, NCT01770392.