he circulating radioactivity.
The sulfoxide and N-glucuronide metabolites show approximately ≥400-fold less in vitro potency against VEGFR-2 compared to axitinib.
Drug-Drug Interaction
Effects of Other Drugs on INLYTA: Axitinib is metabolized primarily in the liver by CYP3A4/5. Additionally, the aqueous solubility of axitinib is pH dependent, with higher pH resulting in lower solubility. The effects of a strong CYP3A4/5 inhibitor, a strong CYP3A4/5 inducer, and an antacid on the pharmacokinetics of axitinib are presented in Figure 1 [see Dosage and Administration (2.2) and Drug Interactions (7.1, 7.2)].
Figure 1. Impact of Co-administered Drugs and Hepatic Impairment on Axitinib Pharmacokinetics
Effects of INLYTA on Other Drugs: In vitro studies demonstrated that axitinib has the potential to inhibit CYP1A2 and CYP2C8. However, co-administration of axitinib with paclitaxel, a CYP2C8 substrate, did not increase plasma concentrations of paclitaxel in patients.
In vitro studies indicated that axitinib does not inhibit CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4/5, or UGT1A1 at therapeutic plasma concentrations. In vitro studies in human hepatocytes indicated that axitinib does not induce CYP1A1, CYP1A2, or CYP3A4/5.
Axitinib is an inhibitor of the efflux transporter P-glycoprotein (P-gp) in vitro. However, INLYTA is not expected to inhibit P-gp at therapeutic plasma concentrations.
Pharmacokinetics in Specific Populations
Pediatric Use: INLYTA has not been studied in patients <18 years of age.
Hepatic Impairment: The effects of hepatic impairment on the pharmacokinetics of axitinib are presented in Figure 1 [see Dosage and Administration (2.2), Warnings and Precautions (5.11), and Use in Specific Populations (8.6)].
Renal Impairment: Population pharmacokinetic analysis (based on pre-existing renal function) was carried out in 590 healthy volunteers and patients, including five with severe renal impairment (15 mL/min ≤CLcr <29 mL/min), 64 with moderate renal impairment (30 mL/min ≤CLcr <59 mL/min), and 139 with mild renal impairment (60 mL/min ≤CLcr <89 mL/min). Mild to severe renal impairment did not have meaningful effects on the pharmacokinetics of axitinib. Data from only one patient with end-stage renal disease are available [see Use in Specific Populations (8.7)].
Other Intrinsic Factors: Population pharmacokinetic analyses indicate that there are no clinically relevant effects of age, gender, race, body weight, body surface area, UGT1A1 genotype, or CYP2C19 genotype on the clearance of axitinib.
13 NONCLINICAL TOXICOLOGY
13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility
Carcinogenicity studies have not been conducted with axitinib.
Axitinib was not mutagenic in an in vitro bacterial reverse mutation (Ames) assay and was not clastogenic in the in vitro human lymphocyte chromosome aberration assay. Axitinib was genotoxic in the in vivo mouse bone marrow micronucleus assay.
INLYTA has the potential to impair reproductive function and fertility in humans. In repeat-dose toxicology studies, findings in the male reproductive tract were observed in the testes/epididymis (decreased organ weight, atrophy or degeneration, decreased numbers of germinal cells, hypospermia or abnormal sperm forms, reduced sperm density and count) at ≥15 mg/kg/dose administered orally twice daily in mice (approximately 7 times the systemic exposure (AUC) in p |
