famitinib and Neoplasms

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.

Topics: East Asian People; Eating; Humans; Indoles; Neoplasms; Receptor Protein-Tyrosine Kinases; Tyrosine Kinase Inhibitors

To evaluate the safety, tolerability, pharmacokinetics and antitumor activities of famitinib (famitinib L-malate), a novel oral multitargeting tyrosine kinase inhibitor that acts against vascular endothelial growth factor receptor-2, platelet-derived growth factor receptor, stem cell factor receptor (c-kit), FMS-like tyrosine kinase-3 receptor and protooncogene tyrosine kinase receptor in patients with advanced solid cancer.. Patients received once daily oral famitinib. Doses were increased from 4 to 8, 13, 20, 27, 24, 25 and eventually 30 mg. Each cycle was defined as 28 days. The pharmacokinetic profile and various biomarkers were evaluated during the first cycle. Antitumor efficacy was evaluated every 8 weeks.. Fifty-four patients were evaluable for safety and efficacy. Dose-limiting toxicities were observed in 2 of 3 patients at 30 mg. The dose-limiting toxicities observed in the first cycle of famitinib treatment included hypertension, hand-foot skin reaction and diarrhea. Grade 3 hypertriglyceridemia/hypercholesterolemia and proteinuria were notable side effects in the subsequent treatment cycles. Other common side effects included bone marrow suppression, oral mucositis, fatigue, pain, elevated transaminase or bilirubin, peripheral sensory disturbance and hypothyroidism, most of which were mild to moderate in severity. Pharmacokinetic studies revealed no significant accumulation of famitinib or its major metabolite, M3. The half-lives of famitinib and M3 were approximately 28.7-33.8 and 41.3-47.7 h, respectively. Food demonstrated a minimal effect on the pharmacokinetics of famitinib. Eight partial responses were determined, including 6 cases of renal cell carcinoma, 1 case of gastrointestinal stromal tumor (GIST) and 1 case of alveolar soft part sarcoma. Fourteen patients demonstrated stable disease with various degrees of tumor shrinkage.. Famitinib is generally well tolerated. Famitinib demonstrates a wide spectrum of antitumor activities, which warrants further study in renal cell carcinoma, GIST, hepatocellular carcinoma and soft tissue sarcoma. The recommended dose for future phase II clinical trials is 25 mg.

Topics: Adult; Aged; Angiogenesis Inhibitors; Biotransformation; Carcinoma, Renal Cell; China; Cohort Studies; Dose-Response Relationship, Drug; Female; Half-Life; Humans; Hypertension; Incidence; Indoles; Kidney Neoplasms; Male; Middle Aged; Neoplasms; Postprandial Period; Protein Kinase Inhibitors; Pyrroles; Receptor Protein-Tyrosine Kinases; Sarcoma; Young Adult

Famitinib is a novel multi-targeted receptor tyrosine kinase inhibitor under development for cancer treatment. This study aims to characterize the metabolic and bioactivation pathways of famitinib.. The metabolites in human plasma, urine and feces were identified via ultra-high performance liquid chromatography-quadrupole-time of flight-mass spectrometry and confirmed using synthetic standards. Biotransformation and bioactivation mechanisms were investigated using microsomes, recombinant metabolic enzymes and hepatocytes.. Famitinib was extensively metabolized after repeated oral administrations. Unchanged famitinib was the major circulating material, followed by N-desethylfaminitib (M3), whose steady-state exposure represented 7.2 to 7.5% that of the parent drug. Metabolites in the excreta were mainly from oxidative deamination (M1), N-desethylation (M3), oxidative defluorination (M7), indolylidene hydroxylation (M9-1 and M9-5) and secondary phase-II conjugations. CYP3A4/5 was the major contributor to M3 formation, CYP3A4/5 and aldehyde dehydrogenase to M1 formation and CYP1A1/2 to M7, M9-1 and M9-5 formations. Minor cysteine conjugates were observed in the plasma, urine and feces, implying the formation of reactive intermediate(s). In vitro microsomal studies proved that famitinib was bioactivated through epoxidation at indolylidene by CYP1A1/2 and spontaneously defluorinated rearrangement to afford a quinone-imine species. A correlation between famitinib hepatotoxicity and its bioactivation was observed in the primary human hepatocytes.. Famitinib is well absorbed and extensively metabolized in cancer patients. Multiple enzymes, mainly CYP3A4/5 and CYP1A1/2, are involved in famitinib metabolic clearance. The quinone-imine intermediate formed through bioactivation may be associated with famitinib hepatotoxicity. Co-administered CYP1A1/2 inducers or inhibitors may potentiate or suppress its hepatotoxicity.

Topics: Administration, Oral; Adult; Antineoplastic Agents; Biotransformation; Cytochrome P-450 Enzyme System; Female; Hepatocytes; Humans; Indoles; Isoenzymes; Male; Microsomes, Liver; Middle Aged; Neoplasms; Oxidation-Reduction; Pyrroles; Receptor Protein-Tyrosine Kinases; Tissue Distribution