The effect of rifampin on the pharmacokinetics of famitinib in healthy subjects

CYP3A inhibitor itraconazole affect pharmacokinetic behavior of famitinib and its active metabolite: results of a single-center, single-arm, open-label and fixed sequence study

BACKGROUND

Famitinib, the novel oral multitargeting tyrosine kinase inhibitor, was developed for treatment of patients with advanced solid cancer. This investigation assessed the pharmacokinetic (PK) effects of itraconazole, an officially recommended CYP3A4 strong inhibitor, on famitinib and its metabolite (SHR116637).

METHODS

A single-center, single-arm, open-label, and fixed sequence study was conducted in 22 healthy subjects. Famitinib was administered as a single oral 15 mg on Day1. Itraconazole 200 mg once daily was given from Day12 to Day24, concomitantly with famitinib on Day15 and for follow-up during Day30 to Day32. Blood sampling followed each famitinib dosage for PK analysis of famitinib and SHR116637. Safety and tolerability were also assessed throughout the treatment.

RESULTS

Cmax, AUC0-t and AUC0-∞ were raised by 40.6%, 77.7% and 81.6%, respectively, and t1/2 was prolonged from 36.08 hours to 48.24 hours for famitinib. In contrast, Cmax, AUC0-t and AUC0-∞ were reduced by 63.5%, 42.6%, and 39.0%, respectively, for SHR116637. Eight (36.4%) subjects reported seventeen treatments that emerged adverse events (all grade 1-2 in severity) all recovered at follow-up period.

CONCLUSIONS

Single oral dose of 15 mg famitinib and co-therapy with 200 mg intraconazole were safe and well tolerated in healthy subjects. Famitinib should be avoided in conjunction with strong CYP3A inhibitors if possible.

TRIAL REGISTRATION

This trial was registered at http://www.chinadrugtrials.org.cn/index.html. (Registration number: CTR20201824.).

Effect of Dietary Intake on the Pharmacokinetics of the Multitargeted Receptor Tyrosine Kinase Inhibitor Famitinib: Results From a Phase 1 Study in Healthy Chinese Participants

Famitinib is a tyrosine kinase inhibitor under clinical investigation for the treatment of solid tumors. Here, a 3-period crossover trial investigated the effect of high-fat or low-fat food intake on the single-dose pharmacokinetic properties of oral famitinib. Twenty-four healthy Chinese participants were enrolled and received a single 25-mg dose of famitinib malate capsule following a high-fat or low-fat breakfast before dosing. Blood samples were collected before dosing (0 hour) to 192 hours after dosing, and famitinib concentrations in plasma were determined with validated liquid chromatography-tandem mass spectrometry. Compared with the fasting condition, the geometric mean ratios for low-fat/fasting were 98.6%, 107.7%, and 107.5% for maximum plasma concentration, area under the plasma concentration-time curve (AUC) over the dosing interval, and AUC from time 0 to infinity, respectively. Those for high-fat/fasting were 84.4%, 105.0%, and 105.1% for maximum plasma concentration, AUC over the dosing interval, and AUC from time 0 to infinity, respectively. There was no significant difference in adverse events between fasting and fed conditions, and no serious adverse events occurred during the trial. In conclusion, oral famitinib bioavailability is not affected by food intake, implying that patients with cancer do not need to consider dietary status when using famitinib. This is considered important for convenience and treatment compliance.