Effect of food on the pharmacokinetics of lonafarnib (SCH 66336) following single and multiple doses

Abstract

Objective: The objective was to determine whether food affects the pharmacokinetics and safety of lonafanib, an orally bioavailable farnesyl transferase inhibitor that is under clinical evaluation for the treatment of various hematologic malignancies and solid tumors.

Methods: Two Phase 1 studies were conducted in separate patient populations. A single-dose study was performed in 12 healthy subjects who received lonafarnib 100 mg under fasted and fed conditions. Additionally, a multiple-dose study was performed in 19 patients with advanced cancer who received lonafarnib 200 mg Q 12 H for 28 days under fasted and fed conditions. Nine of the 19 patients completed both treatment cycles and were used for pharmacokinetic assessment. A 2-week washout period separated treatments in each study. Single-dose pharmacokinetics were assessed at various time points up to 48 hours postdose and multiple-dose pharmacokinetics were assessed at Day 15 for 24 hours postdose.

Results: The pharmacokinetics of lonafarnib were affected by food during single-dose but not multiple-dose administration. Relative oral bioavailabilities (fed vs. fasted) based on log-transformed maximum plasma concentration (C(max)) and area under the concentration-time curve (AUC) were 48% and 77%, respectively, following single-dose administration, and 87% and 96%, respectively, following multiple-dose administration. Intrasubject variability in the pharmacokinetic parameters was less pronounced after multiple dosing (17%) than that after single dosing (33%) of lonafarnib. Intersubject variability was unaffected by food in either study. In the single-dose study, 7 of the 12 subjects (58%) reported treatment emergent adverse events, the most common being headache. No clinically significant differences in adverse events were seen between fasting and fed states after a single dose administration. Thus, single dose 100 mg lonafarnib was safe and generally well tolerated. In the multiple-dose study, all 19 subjects reported at least one treatment-emergent adverse event. General disorders including fatigue and anorexia, and gastrointestinal disorders including diarrhea, vomiting and nausea, were the most commonly reported adverse events after multiple doses. While gastrointestinal adverse events were reported with equal frequency under both fasting (82%, 14/17) and fed states (83%, 15/18), the incidence of severe gastrointestinal adverse events was higher in fasted (47%, 8/17) vs. fed subjects (22%, 4/18) after multiple-dose administration.

Conclusion: The administration of food does not affect the pharmacokinetics of lonafanib following multiple-dose administration. We recommend that multiple-dose lonafarnib should be administered with food to enhance tolerability.