Effect of Food on the Pharmacokinetics of the Oral Docetaxel Tablet Formulation ModraDoc006 Combined with Ritonavir (ModraDoc006/r) in Patients with Advanced Solid Tumours

Introduction: ModraDoc006 is a novel docetaxel tablet formulation that is co-administrated with the cytochrome P450 3A4 and P-glycoprotein inhibitor ritonavir (r): ModraDoc006/r. Objectives: This study evaluated the effect of food consumed prior to administration of ModraDoc006/r on the pharmacokinetics of docetaxel and ritonavir. Methods: Patients with advanced solid tumours were enrolled in this randomized crossover study to receive ModraDoc006/r in a fasted state in week 1 and after a standardized high-fat meal in week 2 and vice versa. Pharmacokinetic sampling was conducted until 48 h after both study drug administrations. Docetaxel and ritonavir plasma concentrations were determined using liquid chromatography with tandem mass spectrometry. Safety was evaluated with the Common Terminology Criteria for Adverse Events, version 4.03. Results: In total, 16 patients completed the food-effect study. The geometric mean ratio (GMR) for the docetaxel area under the plasma concentration–time curve (AUC)_0–48, AUC_0–inf and maximum concentration (C_max) were 1.11 (90% confidence interval [CI] 0.93–1.33), 1.19 (90% CI 1.00–1.41) and 1.07 (90% CI 0.81–1.42) in fed versus fasted conditions, respectively. For the ritonavir C_max, the GMR was 0.79 (90% CI 0.69–0.90), whereas the AUC_0–48 and AUC_0–inf were bioequivalent. The most frequent treatment-related toxicities were grade ≤ 2 diarrhoea and fatigue. Hypokalaemia was the only observed treatment-related grade 3 toxicity. Conclusions: The docetaxel and ritonavir exposure were not bioequivalent, as consumption of a high-fat meal prior to administration of ModraDoc006/r resulted in a slightly higher docetaxel exposure and lower ritonavir C_max. Since docetaxel exposure is the only clinically relevant parameter in our patient population, the overall conclusion is that combined ModraDoc006 and ritonavir treatment may be slightly affected by concomitant intake of a high-fat meal. In view of the small effect, it is most likely that the intake of a light meal will not affect the systemic exposure to docetaxel. ClinicalTrials.gov Identifier: NCT03147378, date of registration: May 10 2017.