Effect of food on exposure to napabucasin: Data from two phase I studies.

Abstract

477 Background: Napabucasin is an orally-administered NAD(P)H quinone dehydrogenase 1–bioactivatable investigational agent hypothesized to affect multiple oncogenic cellular pathways including STAT3. Methods: Food effects on napabucasin pharmacokinetics were evaluated in two studies: one at two sites in Japan (Study 1; JapicCTI-205447) and the other at two sites in the US and three in Canada (Study 2; NCT01775423). Study 1 enrolled healthy Japanese male volunteers (HJMV) who received napabucasin 480 mg (formula 2) per sequential design — fasting on Day (D) 1 followed by a Japanese diet (JD) on D8 — with a 6-D intervening washout. In Study 2, patients (pts) with advanced malignancies received napabucasin 500 mg (formula 1) on D1 in the fasted state, then napabucasin 500 mg (formula 2) on D4 and D8 with a high-fat breakfast [HFB] or in the fasted state per the randomized sequence per crossover design. Results: In Study 1, mean plasma napabucasin levels 6–10 h after napabucasin 480 mg administration were higher in fed (JD) vs fasted states; in the fed state, Cmax increased by 15% and AUClast by ~60% (Table), while tmax decreased by ~1.4 hours. Adverse events (AEs) in Study 1 occurred in 5/6 (83.3%) HJMVs (fasted, n=3; fed, n=5; all grade [gr] 1). In Study 2, mean concentration profiles were comparable in fasted and fed (HFB) states for napabucasin 500 mg. When comparing fasted and fed states, Cmax increased by 21% and AUClast by 39% in the fed state (Table). Interpatient variability was high: geometric CV% for CL/F was 75.9% (fed) and 141% (fasted). AEs in Study 2 occurred in 68% (17/25) of fasted pts (gr 1: n=7; gr 2: n=8; gr 3, n=2) and 50% (7/14) of pts fed an HFB (gr 1: n=2; gr 2: n=3; gr 3, n=2). Conclusions: In HJMVs, napabucasin 480 mg administered with a JD increased exposure (Cmax; AUClast; AUCinf) and decreased tmax vs the fasted state. In pts with advanced malignancies, napabucasin 500 mg administered with an HFB increased exposure (Cmax; AUClast) vs the fasted state. These exposure increases are not considered to be of clinical relevance. Clinical trial information: JapicCTI-205447; NCT01775423. [Table: see text]