Purpose: Vismodegib, an orally bioavailable small-molecule Smoothened inhibitor, is approved for treatment of advanced basal cell carcinoma (BCC). We conducted a pharmacokinetic study of vismodegib in patients with advanced solid tumors to explore the effects of food on drug exposure.
Experimental design: In part I, patients were randomized to fasting overnight (FO), a high fat meal (HF), or a low fat meal (LF) before a single dose of vismodegib 150 mg. Plasma concentrations of vismodegib were determined by a validated liquid chromatography-tandem mass spectrometry assay. Primary endpoints were C(max) and area under the curve (AUC(0-168)). In part II, patients randomized to FO or HF in part I took vismodegib 150 mg daily after fasting; those randomized to LF took it after a meal. Primary endpoints after two weeks were C(max) and AUC(0-24).
Results: Sixty (22 FO, 20 HF, 18 LF) and 52 (25 fasting, 27 fed) patients were evaluable for primary endpoints in parts I and II, respectively. Mean C(max) and AUC(0-168) after a single dose were higher in HF than FO patients [ratios of geometric means (90% CI) = 1.75 (1.30, 2.34) and 1.74 (1.25, 2.42), respectively]. There were no significant differences in C(max) or AUC(0-24) between fasting and fed groups after daily dosing. The frequencies of drug-related toxicities were similar in both groups.
Conclusions: A HF meal increases plasma exposure to a single dose of vismodegib, but there are no pharmacokinetic or safety differences between fasting and fed groups at steady-state. Vismodegib may be taken with or without food for daily dosing.