Chemical formula: C₂₁H₂₂Cl₂FN₅O Molecular mass: 450.337 g/mol PubChem compound: 11626560
Crizotinib is a selective small-molecule inhibitor of the ALK receptor tyrosine kinase (RTK) and its oncogenic variants (i.e. ALK fusion events and selected ALK mutations). Crizotinib is also an inhibitor of the Hepatocyte Growth Factor Receptor (HGFR, c-Met) RTK, ROS1 (c-ros) and Recepteur d’Origine Nantais (RON) RTK.
Crizotinib demonstrated concentration-dependent inhibition of the kinase activity of ALK, ROS1, and c-Met in biochemical assays and inhibited phosphorylation and modulated kinase-dependent phenotypes in cell-based assays. Crizotinib demonstrated potent and selective growth inhibitory activity and induced apoptosis in tumour cell lines exhibiting ALK fusion events (including echinoderm microtubule-associated protein-like 4 [EML4]-ALK and nucleophosmin [NPM]-ALK), ROS1 fusion events, or exhibiting amplification of the ALK or MET gene locus.
Crizotinib demonstrated antitumour efficacy, including marked cytoreductive antitumour activity, in mice bearing tumour xenografts that expressed ALK fusion proteins. The antitumour efficacy of crizotinib was dose-dependent and correlated to pharmacodynamic inhibition of phosphorylation of ALK fusion proteins (including EML4-ALK and NPM-ALK) in tumours in vivo. Crizotinib also demonstrated marked antitumour activity in mouse xenograft studies, where tumours were generated using a panel of NIH-3T3 cell lines engineered to express key ROS1 fusions identified in human tumours. The antitumour efficacy of crizotinib was dose-dependent and demonstrated a correlation with inhibition of ROS1 phosphorylation in vivo.
Following oral single dose administration in the fasted state, crizotinib is absorbed with median time to achieve peak concentrations of 4 to 6 hours. With twice daily dosing, steady state was achieved within 15 days. The absolute bioavailability of crizotinib was determined to be 43% following the administration of a single 250 mg oral dose.
A high-fat meal reduced crizotinib AUCinf and Cmax by approximately 14% when a 250 mg single dose was given to healthy volunteers. Crizotinib can be administered with or without food.
The geometric mean volume of distribution (Vss) of crizotinib was 1772 L following intravenous administration of a 50 mg dose, indicating extensive distribution into tissues from the plasma.
Binding of crizotinib to human plasma proteins in vitro is 91% and is independent of medicinal product concentration. In vitro studies suggest that crizotinib is a substrate for P-glycoprotein (P-gp).
In vitro studies demonstrated that CYP3A4/5 were the major enzymes involved in the metabolic clearance of crizotinib. The primary metabolic pathways in humans were oxidation of the piperidine ring to crizotinib lactam and O-dealkylation, with subsequent Phase 2 conjugation of O-dealkylated metabolites.
In vitro studies in human liver microsomes demonstrated that crizotinib is a time-dependent inhibitor of CYP2B6 and CYP3A. In vitro studies indicated that clinical drug-drug interactions are unlikely to occur as a result of crizotinib-mediated inhibition of the metabolism of medicinal products that are substrates for CYP1A2, CYP2C8, CYP2C9, CYP2C19 or CYP2D6.
In vitro studies showed that crizotinib is a weak inhibitor of UGT1A1 and UGT2B7. However, in vitro studies indicated that clinical drug-drug interactions are unlikely to occur as a result of crizotinib-mediated inhibition of the metabolism of drugs that are substrates for UGT1A4, UGT1A6, or UGT1A9.
In vitro studies in human hepatocytes indicated that clinical drug-drug interactions are unlikely to occur as a result of crizotinib-mediated induction of the metabolism of medicinal products that are substrates for CYP1A2.
Following single doses of crizotinib, the apparent plasma terminal half-life of crizotinib was 42 hours in patients.
Following the administration of a single 250 mg radiolabeled crizotinib dose to healthy subjects, 63% and 22% of the administered dose was recovered in faeces and urine, respectively. Unchanged crizotinib represented approximately 53% and 2.3% of the administered dose in faeces and urine, respectively.
Crizotinib is an inhibitor of P-glycoprotein (P-gp) in vitro. Therefore, crizotinib may have the potential to increase plasma concentrations of coadministered medicinal products that are substrates of P-gp.
Crizotinib is an inhibitor of OCT1 and OCT2 in vitro. Therefore, crizotinib may have the potential to increase plasma concentrations of coadministered drugs that are substrates of OCT1 or OCT2.
In vitro, crizotinib did not inhibit the human hepatic uptake transport proteins organic anion transporting polypeptide (OATP)1B1 or OATP1B3 or the renal uptake transport proteins organic anion transporter (OAT)1 or OAT3 at clinically relevant concentrations. Therefore, clinical drug-drug interactions are unlikely to occur as a result of crizotinib-mediated inhibition of the hepatic or renal uptake of medicinal products that are substrates for these transporters.
In vitro, crizotinib is not an inhibitor of BSEP at clinically relevant concentrations.
Crizotinib is extensively metabolized in the liver. Patients with mild (either AST >ULN and total bilirubin ≤ULN or any AST and total bilirubin >ULN but 1.5×ULN), moderate (any AST and total bilirubin >1.5×ULN and 3×ULN), or severe (any AST and total bilirubin >3×ULN) hepatic impairment or normal (AST and total bilirubin ≤ULN) hepatic function, who were matched controls for mild or moderate hepatic impairment, were enrolled in an open-label, non-randomised clinical study (Study 1012), based on NCI classification.
Following crizotinib 250 mg twice daily dosing, patients with mild hepatic impairment (N=10) showed similar systemic crizotinib exposure at steady state compared to patients with normal hepatic function (N=8), with geometric mean ratios for area under the plasma concentration-time curve as daily exposure at steady state (AUCdaily) and Cmax of 91.1% and 91.2%, respectively. No starting dose adjustment is recommended for patients with mild hepatic impairment.
Following crizotinib 200 mg twice daily dosing, patients with moderate hepatic impairment (N=8) showed higher systemic crizotinib exposure compared to patients with normal hepatic function (N=9) at the same dose level, with geometric mean ratios for AUCdaily and Cmax of 150% and 144%, respectively. However, the systemic crizotinib exposure in patients with moderate hepatic impairment at the dose of 200 mg twice daily was comparable to that observed from patients with normal hepatic function at a dose of 250 mg twice daily, with geometric mean ratios for AUCdaily and Cmax of 114% and 109%, respectively.
The systemic crizotinib exposure parameters AUCdaily and Cmax in patients with severe hepatic impairment (N=6) receiving a crizotinib dose of 250 mg once daily were approximately 64.7% and 72.6%, respectively, of those from patients with normal hepatic function receiving a dose of 250 mg twice daily.
An adjustment of the dose of crizotinib is recommended when administering crizotinib to patients with moderate or severe hepatic impairment.
Patients with mild (60≤CLcr<90 mL/min) and moderate (30≤CLcr<60 mL/min) renal impairment were enrolled in single-arm Studies 1001 and 1005. The effect of renal function as measured by baseline CLcr on observed crizotinib steady-state trough concentrations (Ctrough,ss) was evaluated. In Study 1001, the adjusted geometric mean of plasma Ctrough,ss in mild (N=35) and moderate (N=8) renal impairment patients were 5.1% and 11% higher, respectively, than those in patients with normal renal function. In Study 1005, the adjusted geometric mean Ctrough,ss of crizotinib in mild (N=191) and moderate (N=65) renal impairment groups were 9.1% and 15% higher, respectively, than those in patients with normal renal function. In addition, the population pharmacokinetic analysis using data from Studies 1001, 1005 and 1007 indicated CLcr did not have a clinically meaningful effect on the pharmacokinetics of crizotinib. Due to the small size of the increases in crizotinib exposure (5%-15%), no starting dose adjustment is recommended for patients with mild or moderate renal impairment.
After a single 250 mg dose in subjects with severe renal impairment (CLcr <30 mL/min) not requiring peritoneal dialysis or haemodialysis, crizotinib AUCinf and Cmax increased by 79% and 34%, respectively, compared to those with normal renal function. An adjustment of the dose of crizotinib is recommended when administering crizotinib to patients with severe renal impairment not requiring peritoneal dialysis or haemodialysis.
Based on the population pharmacokinetic analysis of data from Studies 1001, 1005, and 1007, age has no effect on crizotinib pharmacokinetics.
Based on the population pharmacokinetic analysis of data from Studies 1001, 1005 and 1007, there was no clinically meaningful effect of body weight or gender on crizotinib pharmacokinetics.
Based on the population pharmacokinetic analysis of data from Studies 1001, 1005 and 1007, the predicted area under the plasma concentration-time curve at steady-state (AUCss) (95% CI) was 23%-37% higher in Asian patients (N=523) than in non-Asian patients (N=691).
In studies in patients with ALK-positive advanced NSCLC (N=1669), the following adverse reactions were reported with an absolute difference of ≥10% in Asian patients (N=753) than in non-Asian patients (N=916): elevated transaminases, decreased appetite, neutropenia, and leukopenia. No adverse drug reactions were reported with an absolute difference of ≥15%.
Limited data are available in this subgroup of patients. Based on the population pharmacokinetic analysis of data in Studies 1001, 1005 and 1007, age has no effect on crizotinib pharmacokinetics.
The QT interval prolongation potential of crizotinib was assessed in patients with either ALK-positive or ROS1-positive NSCLC who received crizotinib 250 mg twice daily. Serial ECGs in triplicate were collected following a single dose and at steady state to evaluate the effect of crizotinib on QT intervals. Thirty-four of 1619 patients (2.1%) with at least 1 postbaseline ECG assessment were found to have QTcF ≥500 msec, and 79 of 1585 patients (5.0%) with a baseline and at least 1 postbaseline ECG assessment had an increase from baseline QTcF ≥60 msec by automated machine-read evaluation of ECG.
An ECG substudy using blinded manual ECG measurements was conducted in 52 ALK-positive NSCLC patients who received crizotinib 250 mg twice daily. Eleven (21%) patients had an increase from Baseline in QTcF value ≥30 to <60 msec and 1 (2%) patient had an increase from Baseline in QTcF value of ≥60 msec. No patients had a maximum QTcF ≥480 msec. The central tendency analysis indicated that all upper limits of the 90% CI for the LS mean change from Baseline in QTcF at all Cycle 2 Day 1 time points were <20 msec. A pharmacokinetic/pharmacodynamic analysis suggested a relationship between crizotinib plasma concentration and QTc. In addition, a decrease in heart rate was found to be associated with increasing crizotinib plasma concentration, with a maximum mean reduction of 17.8 beats per minute (bpm) after 8 hours on Cycle 2 Day 1.
In rat and dog repeat-dose toxicity studies up to 3-month duration, the primary target organ effects were related to the gastrointestinal (emesis, faecal changes, congestion), haematopoietic (bone marrow hypocellularity), cardiovascular (mixed ion channel blocker, decreased heart rate and blood pressure, increased LVEDP, QRS and PR intervals, and decreased myocardial contractility), or reproductive (testicular pachytene spermatocyte degeneration, single-cell necrosis of ovarian follicles) systems. The No Observed Adverse Effect Levels (NOAEL) for these findings were either subtherapeutic or up to 2.6-fold human clinical exposure based on AUC. Other findings included an effect on the liver (elevation of liver transaminases) and retinal function, and potential for phospholipidosis in multiple organs without correlative toxicities.
Crizotinib was not mutagenic in vitro in the bacterial reverse mutation (Ames) assay. Crizotinib was aneugenic in an in vitro micronucleus assay in Chinese Hamster Ovary cells and in an in vitro human lymphocyte chromosome aberration assay. Small increases of structural chromosomal aberrations at cytotoxic concentrations were seen in human lymphocytes. The NOAEL for aneugenicity was approximately 1.8-fold human clinical exposure based on AUC.
Carcinogenicity studies with crizotinib have not been performed.
No specific studies with crizotinib have been conducted in animals to evaluate the effect on fertility; however, crizotinib is considered to have the potential to impair reproductive function and fertility in humans based on findings in repeat-dose toxicity studies in the rat. Findings observed in the male reproductive tract included testicular pachytene spermatocyte degeneration in rats given ≥50 mg/kg/day for 28 days (approximately 1.1-fold human clinical exposure based on AUC). Findings observed in the female reproductive tract included single-cell necrosis of ovarian follicles of a rat given 500 mg/kg/day for 3 days.
Crizotinib was not shown to be teratogenic in pregnant rats or rabbits. Post-implantation loss was increased at doses ≥50 mg/kg/day (approximately 0.4 times the AUC at the recommended human dose) in rats, and reduced fetal body weights were considered adverse effects in the rat and rabbit at 200 and 60 mg/kg/day, respectively (approximately 1.2-fold human clinical exposure based on AUC).
Decreased bone formation in growing long bones was observed in immature rats at 150 mg/kg/day following once daily dosing for 28 days (approximately 3.3 times human clinical exposure based on AUC). Other toxicities of potential concern to paediatric patients have not been evaluated in juvenile animals.
The results of an in vitro phototoxicity study demonstrated that crizotinib may have phototoxic potential.
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