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Purpose: Axitinib, a tyrosine kinase inhibitor targeting vascular endothelial growth factor receptors 1-3, is approved for second-line treatment of advanced renal cell carcinoma. Axitinib is partially metabolized by cytochrome P450 1A2, which is induced by chronic heavy smoking. The effect of smoking on axitinib pharmacokinetics was evaluated in a non-small-cell lung cancer (NSCLC) patient population with a large number of active and ex-smokers., Methods: Data were pooled from six clinical studies-serial pharmacokinetics from two healthy volunteer studies (n = 58) and sparse pharmacokinetics from four NSCLC studies (n = 152)-for a nonlinear mixed effects modeling (NONMEM v7.2) analysis. Demographics, smoking status, liver and renal function status, and Eastern Cooperative Oncology Group performance status were tested as covariates., Results: There were 83 (40%) active smokers and 56 (27%) ex-smokers in the pooled dataset. Axitinib pharmacokinetics was adequately described with a linear, two-compartment model with a lagged first-order absorption. Final parameter estimates (inter-individual variability) were 16.1 L/h (59.1%) and 45.3 L (54.4%) for systemic clearance (CL) and central volume of distribution (Vc), respectively. Smoking status was found not to alter CL or Vc. Asian ethnicity and body weight were significant covariates for Vc, but were not considered clinically relevant since individual values of Vc for Asians were within the range of non-Asians., Conclusions: Based on this analysis, smoking status does not affect area under plasma concentration-time curve, and thus no dose adjustment is required for smokers.

Background: Axitinib, an inhibitor of vascular endothelial growth factor (VEGF) receptors, is approved as second-line treatment for advanced renal cell carcinoma (RCC). Agents targeting the VEGF pathway may induce renal toxicities, which may be influenced by pre-existing renal dysfunction., Objective: The objective was to characterize axitinib pharmacokinetics and safety in patients with renal impairment., Patients and Methods: Effect of renal function (baseline creatinine clearance [CrCL]) on axitinib clearance was evaluated in a population pharmacokinetic model in 207 patients with advanced solid tumors who received a standard axitinib starting dose, and in 383 healthy volunteers. Axitinib safety according to baseline CrCL was assessed in previously treated patients with RCC (n = 350) who received axitinib in the phase 3 AXIS study., Results: Median axitinib clearance was 14.0, 10.7, 12.3, 7.81, and 12.6 L/h, respectively, in individuals with normal renal function (≥90 ml/min; n = 381), mild renal impairment (60-89 ml/min; n = 139), moderate renal impairment (30-59 ml/min; n = 64), severe renal impairment (15-29 ml/min; n = 5), and end-stage renal disease (<15 ml/min; n = 1). The population pharmacokinetic model adequately predicted axitinib clearance in individuals with severe renal impairment or end-stage renal disease. Grade ≥3 adverse events (AEs) were reported in 63 % of patients with normal renal function or mild impairment, 77 % with moderate impairment, and 50 % with severe impairment; study discontinuations due to AEs were 10 %, 11 %, and 0 %, respectively., Conclusions: Axitinib pharmacokinetics and safety were similar regardless of baseline renal function; no starting-dose adjustment is needed for patients with pre-existing mild to severe renal impairment.

Background: Increased blood pressure (BP) is commonly observed in patients treated with vascular endothelial growth factor pathway inhibitors, including axitinib. Ambulatory BP monitoring (ABPM) and pharmacokinetic data were collected in a randomised, double-blind phase II study of axitinib with or without dose titration in previously untreated patients with metastatic renal cell carcinoma., Objective: Aims of these analyses were to (1) develop a population pharmacokinetic-pharmacodynamic model for describing the relationship between axitinib exposure and changes in diastolic BP (dBP) and (2) simulate changes in dBP with different axitinib dosing regimens., Methods: We employed a three-stage modelling approach, which included development of (1) a baseline 24-h ABPM model, (2) a pharmacokinetic model from serial and sparse pharmacokinetic data, and (3) an indirect-response, maximum-effect (Emax) model to evaluate the exposure-driven effect of axitinib on dBP. Simulations (N = 1,000) were performed using the final pharmacokinetic-pharmacodynamic model to evaluate dBP changes on days 4 and 15 of treatment with different axitinib doses., Results: Baseline ABPM data from 62 patients were best described by 24-h mean dBP and two cosine terms. The final indirect-response Emax model showed good agreement between observed 24-h ABPM data and population and individual predictions. The maximum increase in dBP was 20.8 %, and the axitinib concentration at which 50 % of the maximal increase in dBP was reached was 12.4 ng/mL., Conclusion: Our model adequately describes the relationship between axitinib exposure and dBP increases. Results from these analyses may potentially be applied to infer dBP changes in patients administered axitinib at nonstandard doses.

Axitinib, a potent and selective tyrosine kinase inhibitor of vascular endothelial growth factor receptors 1, 2, and 3, showed improved progression-free survival over sorafenib in patients previously treated for advanced renal cell carcinoma in the AXIS trial. Although a few studies had established the efficacy and safety of axitinib in Asian patients, additional evaluation was necessary to obtain regulatory approval in several Asian countries, especially in light of ethnic differences that are known to exist in genetic polymorphisms for metabolizing enzymes such as cytochrome P450 (CYP) 3A5, CYP2C19 and uridine diphosphate glucuronosyltransferase (UGT) 1A1, which are involved in axitinib metabolism. Axitinib plasma pharmacokinetics following single or multiple administration of oral axitinib in Asian (Japanese or Chinese) healthy subjects as well as Asian patients with advanced solid tumors was compared with that obtained in Caucasians. Upon review, the data demonstrated that axitinib can be characterized as not sensitive to ethnic factors based on its pharmacokinetic and pharmacodynamic properties. Axitinib exhibited similar pharmacokinetics in Asian and non-Asian subjects. A pooled population pharmacokinetic analysis indicated lack of a clinically meaningful effect of ethnicity on axitinib disposition. Therefore, dose adjustment for axitinib on the basis of ethnicity is not currently warranted.

Purpose: Axitinib is a potent and selective inhibitor of vascular endothelial growth factor receptors 1-3, approved for second-line treatment of advanced renal cell carcinoma (RCC). Preclinical studies did not indicate potential for axitinib-induced delayed cardiac repolarization., Methods: The effect of axitinib on corrected QT (QTc) prolongation was evaluated with one-stage concentration-QTc response modeling using data from a definitive randomized crossover QT phase I study in healthy volunteers administered one single 5-mg axitinib dose alone or in the presence of steady-state ketoconazole (400 mg once daily)., Results: Axitinib and ketoconazole had opposite effects on heart rate: Axitinib lowered it, ketoconazole raised it. The final analysis showed a flat relationship between QTc and axitinib concentration (slope -0.0314 ms·mL/ng) for axitinib alone. Mean highest placebo-matched change from baseline in QTc was -3.0 [90 % confidence interval (CI) -5.4, -0.6] ms. At supratherapeutic axitinib exposures achieved with potent cytochrome P450 3A4/5 inhibition by ketoconazole, the model predicted mean QTc change of 6.5 (90 % CI 4.4-8.5) ms. The slope population mean estimate was -0.331 (95 % CI -0.860, 0.198) ms·mL/µg for ketoconazole alone and 0.0725 (0.0445-0.1005) ms·mL/ng for axitinib in the presence of ketoconazole. The results were then compared with those obtained based on more widely used Fridericia's, Bazett's, and study-specific correction methods., Conclusions: Since axitinib plasma concentrations observed in this study exceeded the range of concentrations observed in patients with RCC at the highest approved clinical dose (10 mg twice daily), axitinib was not associated with clinically significant QTc prolongation in target populations.

Purpose: Axitinib, a potent and selective inhibitor of vascular endothelial growth factor receptors, showed antitumor activity as a single agent against several solid tumor types in Phase II and III trials. This study was conducted to evaluate axitinib pharmacokinetics across a variety of solid tumors., Methods: The current study analyzed the pharmacokinetics of axitinib in 110 patients with non-small cell lung cancer (NSCLC), thyroid cancer, or melanoma from three Phase II trials plus 127 healthy volunteers, using nonlinear mixed-effects modeling. Boxplots of maximum observed plasma concentration (C max) and area under the plasma concentration-time curve (AUC) of data from these tumor populations was compared to C max and AUC from the final population pharmacokinetic model developed for metastatic renal cell carcinoma (mRCC) to compare axitinib pharmacokinetics across different tumor types., Results: Axitinib disposition based on data from 237 subjects was best described using a two-compartment model with first-order absorption and lag time. Population estimates for systemic clearance, central volume of distribution, absorption rate constant, absolute bioavailability, and lag time were 20.1 L/h, 56.2 L, 1.26/h(-1), 0.663, and 0.448 h, respectively. Statistically significant covariates included gender on clearance, and body weight on central volume of distribution. However, predicted changes due to gender and body weight were found not clinically meaningful. The final analysis indicated that the pharmacokinetic model for mRCC was able to successfully describe axitinib pharmacokinetics in patients with NSCLC, thyroid cancer, and melanoma., Conclusion: The pharmacokinetics of axitinib appears to be similar across a variety of tumor types.

Background: In a previous phase 2 trial, axitinib was active and well tolerated in patients with advanced thyroid cancer. In this second phase 2 trial, the efficacy and safety of axitinib were evaluated further in this population, and pharmacokinetic/pharmacodynamic relationships and patient-reported outcomes were assessed., Methods: Patients (N = 52) with metastatic or unresectable, locally advanced medullary or differentiated thyroid cancer that was refractory or not amenable to iodine-131 received a starting dose of axitinib 5 mg twice daily. The primary endpoint was the objective response rate (ORR). Secondary endpoints included progression-free survival (PFS), overall survival (OS), safety, pharmacokinetic parameters, and patient-reported outcomes assessed with the MD Anderson Symptom Inventory questionnaire., Results: The overall ORR was 35% (18 partial responses), and 18 patients had stable disease for ≥16 weeks. The median PFS was 16.1 months, and the median OS was 27.2 months. All-causality, grade ≥3 adverse events (>5%) were fatigue, dyspnea, diarrhea, decreased weight, pain in extremity, hypertension, decreased appetite, palmar-plantar erythrodysesthesia, hypocalcemia, and myalgia. Patients who had greater axitinib exposure had a longer median PFS. Quality of life was maintained during treatment with axitinib, and no significant deterioration in symptoms or interference in daily life caused by symptoms, assessed on MD Anderson Symptom Inventory subscales, were observed., Conclusions: Axitinib has activity and a manageable safety profile while maintaining quality of life, and it represents an additional treatment option for patients with advanced thyroid cancer., (© 2014 American Cancer Society.)

Purpose: An overview of the responses to some of the most frequently asked questions regarding axitinib administration and dosage modifications used in clinical practice are presented., Summary: Axitinib was approved for second-line treatment of advanced renal cell carcinoma by the Food and Drug Administration on January 27, 2012. Inquiries received over the first six months after the approval date were reviewed. A large number of questions were related to administration of axitinib in different patient populations or in patients with various comorbidities, such as its (1) use in patients unable to swallow oral medication or administration of axitinib via a nasogastric tube, (2) use in patients with renal or hepatic impairment, (3) central nervous system penetration and use in patients with brain metastases, (4) drug interactions, particularly with anticoagulants, and (5) dosage modifications. Responses to these inquiries were provided based on the published literature or from data on file from the manufacturer. The dosage of axitinib can be adjusted for use in patients with hepatic impairment or in patients who cannot otherwise tolerate the usual regimen. Patients taking concomitant warfarin can also take axitinib, and patients who cannot swallow oral medications can receive a liquid formulation of the drug, though its efficacy and comparability to the tablet formulation has not been tested., Conclusion: Based on the published literature and company data on file, the axitinib dosage may be modified to accommodate patients with renal or hepatic impairment, who cannot swallow oral medication, are receiving concomitant warfarin, or who cannot otherwise tolerate the standard dosage regimen. For patients who cannot swallow, an oral suspension can be prepared because crushing axitinib is not recommended., (Copyright © 2014 by the American Society of Health-System Pharmacists, Inc. All rights reserved.)

The disposition of a single oral dose of 5 mg (100 μCi) of [(14)C]axitinib was investigated in fasted healthy human subjects (N = 8). Axitinib was rapidly absorbed, with a median plasma Tmax of 2.2 hours and a geometric mean Cmax and half-life of 29.2 ng/ml and 10.6 hours, respectively. The plasma total radioactivity-time profile was similar to that of axitinib but the AUC was greater, suggesting the presence of metabolites. The major metabolites in human plasma (0-12 hours), identified as axitinib N-glucuronide (M7) and axitinib sulfoxide (M12), were pharmacologically inactive, and with axitinib comprised 50.4%, 16.2%, and 22.5% of the radioactivity, respectively. In excreta, the majority of radioactivity was recovered in most subjects by 48 hours postdose. The median radioactivity excreted in urine, feces, and total recovery was 22.7%, 37.0%, and 59.7%, respectively. The recovery from feces was variable across subjects (range, 2.5%-60.2%). The metabolites identified in urine were M5 (carboxylic acid), M12 (sulfoxide), M7 (N-glucuronide), M9 (sulfoxide/N-oxide), and M8a (methylhydroxy glucuronide), accounting for 5.7%, 3.5%, 2.6%, 1.7%, and 1.3% of the dose, respectively. The drug-related products identified in feces were unchanged axitinib, M14/15 (mono-oxidation/sulfone), M12a (epoxide), and an unidentified metabolite, comprising 12%, 5.7%, 5.1%, and 5.0% of the dose, respectively. The proposed mechanism to form M5 involved a carbon-carbon bond cleavage via M12a, followed by rearrangement to a ketone intermediate and subsequent Baeyer-Villiger rearrangement, possibly through a peroxide intermediate. In summary, the study characterized axitinib metabolites in circulation and primary elimination pathways of the drug, which were mainly oxidative in nature.

Aims: Axitinib is a potent and selective second generation inhibitor of vascular endothelial growth factor receptors 1, 2 and 3 approved for second line treatment of advanced renal cell carcinoma. The objectives of this analysis were to assess plasma pharmacokinetics and identify covariates that may explain variability in axitinib disposition following single dose administration in healthy volunteers., Methods: Plasma concentration-time data from 337 healthy volunteers in 10 phase I studies were analyzed, using non-linear mixed effects modelling (nonmem) to estimate population pharmacokinetic parameters and evaluate relationships between parameters and food, formulation, demographic factors, measures of renal and hepatic function and metabolic genotypes (UGT1A1*28 and CYP2C19)., Results: A two compartment structural model with first order absorption and lag time best described axitinib pharmacokinetics. Population estimates for systemic clearance (CL), central volume of distribution (Vc ), absorption rate constant (ka ) and absolute bioavailability (F) were 17.0 l h(-1) , 45.3 l, 0.523 h(-1) and 46.5%, respectively. With axitinib Form IV, ka and F increased in the fasted state by 207% and 33.8%, respectively. For Form XLI (marketed formulation), F was 15% lower compared with Form IV. CL was not significantly influenced by any of the covariates studied. Body weight significantly affected Vc , but the effect was within the estimated interindividual variability for Vc ., Conclusions: The analysis established a model that adequately characterizes axitinib pharmacokinetics in healthy volunteers. Vc was found to increase with body weight. However, no change in plasma exposures is expected with change in body weight; hence no dose adjustment is warranted., (© 2013 The British Pharmacological Society.)

Background: Population pharmacokinetic data suggest axitinib plasma exposure correlates with efficacy in metastatic renal-cell carcinoma. Axitinib dose titration might optimise exposure and improve outcomes. We prospectively assessed the efficacy and safety of axitinib dose titration in previously untreated patients with metastatic renal-cell carcinoma., Methods: In this randomised, double-blind, multicentre, phase 2 study, patients were enrolled from 49 hospitals and outpatient clinics in the Czech Republic, Germany, Japan, Russia, Spain, and USA. Patients with treatment-naive metastatic renal-cell carcinoma received axitinib 5 mg twice daily during a 4 week lead-in period. Those patients with blood pressure 150/90 mm Hg or lower, no grade 3 or 4 treatment-related toxic effects, no dose reductions, and no more than two antihypertensive drugs for 2 consecutive weeks were stratified by Eastern Cooperative Oncology Group performance status (0 vs 1), and then randomly assigned (1:1) to either masked titration with axitinib to total twice daily doses of 7 mg, and then 10 mg, if tolerated, or placebo titration. Patients who did not meet these criteria continued without titration. The primary objective was comparison of the proportion of patients achieving an objective response between randomised groups. Safety analyses were based on all patients who received at least one dose of axitinib., Findings: Between Sept 2, 2009, and Feb 28, 2011, we enrolled 213 patients, of whom 112 were randomly assigned to either the axitinib titration group (56 patients) or the placebo titration group (56 patients). 91 were not eligible for titration, and ten withdrew during the lead-in period. 30 patients (54%, 95% CI 40-67) in the axitinib titration group had an objective response, as did 19 patients (34%, 22-48]) in the placebo titration group (one-sided p=0·019). 54 (59%, 95% CI 49-70) of non-randomised patients achieved an objective response. Common grade 3 or worse, all-causality adverse events in treated patients were hypertension (ten [18%] of 56 in the axitinib titration group vs five [9%] of 56 in the placebo titration group vs 45 [49%] of 91 in the non-randomised group), diarrhoea (seven [13%] vs two [4%] vs eight [9%]), and decreased weight (four [7%] vs three [5%] vs six [7%]). One or more all-causality serious adverse events were reported in 15 (27%) patients in the axitinib titration group, 13 (23%) patients in the placebo titration group, and 35 (38%) non-randomised patients. The most common serious adverse events in all 213 patients were disease progression and dehydration (eight each [4%]), and diarrhoea, vomiting, pneumonia, and decreased appetite (four each [2%])., Interpretation: The greater proportion of patients in the axitinib titration group achieving an objective response supports the concept of individual axitinib dose titration in selected patients with metastatic renal-cell carcinoma. Axitinib shows clinical activity with a manageable safety profile in treatment-naive patients with this disease., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Axitinib is a potent and selective second-generation inhibitor of vascular endothelial growth factor receptors 1, 2, and 3 that is approved in the US and several other countries for treatment of patients with advanced renal cell carcinoma after failure of one prior systemic therapy. The recommended clinical starting dose of axitinib is 5 mg twice daily, taken with or without food. Dose increase (up to a maximum of 10 mg twice daily) or reduction is permitted based on individual tolerability. Axitinib pharmacokinetics are dose-proportional within 1-20 mg twice daily, which includes the clinical dose range. Axitinib has a short effective plasma half-life (range 2.5-6.1 h), and the plasma accumulation of axitinib is in agreement with what is expected based on the plasma half-life of the drug. Axitinib is absorbed relatively rapidly, reaching maximum observed plasma concentrations (C max) within 4 h of oral administration. The mean absolute bioavailability of axitinib is 58 %. Axitinib is highly (>99 %) bound to human plasma proteins with preferential binding to albumin and moderate binding to α1-acid glycoprotein. In patients with advanced renal cell carcinoma, at the 5-mg twice-daily dose in the fed state, the geometric mean (% coefficient of variation) C max and area under the plasma concentration-time curve (AUC) from time 0-24 h (AUC24) were 27.8 ng/mL (79 %) and 265 ng·h/mL (77 %), respectively. Axitinib is metabolized primarily in the liver by cytochrome P450 (CYP) 3A4/5 and, to a lesser extent (<10 % each), by CYP1A2, CYP2C19, and uridine diphosphate glucuronosyltransferase (UGT) 1A1. The two major human plasma metabolites, M12 (sulfoxide product) and M7 (glucuronide product), are considered pharmacologically inactive. Axitinib is eliminated via hepatobiliary excretion with negligible urinary excretion. Although mild hepatic impairment does not affect axitinib plasma exposures compared with subjects with normal hepatic function, there was a 2-fold increase in AUC from time zero to infinity (AUC∞) following a single 5-mg dose in subjects with moderate hepatic impairment. In the presence of ketoconazole, a strong CYP3A4/5 inhibitor, axitinib C max and AUC∞ increased by 1.5- and 2-fold, respectively, whereas co-administration of rifampin, a strong CYP3A4/5 inducer, resulted in a 71 and 79 % decrease in the C max and AUC∞, respectively. Axitinib does not inhibit CYP3A4/5, CYP1A2, CYP2C8, CYP2A6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, or UGT1A1 at concentrations obtained with the clinical doses and is not expected to have major interactions with drugs that are metabolized by these enzymes. Axitinib is an inhibitor of the efflux transporter P-glycoprotein (P-gp) in vitro, but is not expected to inhibit P-gp at therapeutic plasma concentrations. A two-compartment population pharmacokinetic model with first-order absorption and lag time was used to describe axitinib pharmacokinetics. No clinically relevant effects of age, sex, body weight, race, renal function, UGT1A1 genotype, or CYP2C19 inferred phenotype on the clearance of axitinib were identified.

Axitinib is a potent and selective inhibitor of vascular endothelial growth factor receptors 1, 2, and 3, approved for second-line therapy for advanced renal cell carcinoma (RCC). Axitinib population pharmacokinetic and pharmacokinetic/pharmacodynamic relationships were evaluated. Using nonlinear mixed effects modeling with pooled data from 383 healthy volunteers, 181 patients with metastatic RCC, and 26 patients with other solid tumors in 17 trials, the disposition of axitinib was best described by a 2-compartment model with first-order absorption and a lag time, with estimated mean systemic clearance (CL) of 14.6 L/h and central volume of distribution (V(c)) of 47.3 L. Of 12 covariates tested, age over 60 years and Japanese ethnicity were associated with decreased CL, whereas V(c) increased with body weight. However, the magnitude of predicted changes in exposure based on these covariates does not warrant dose adjustments. Multivariate Cox proportional hazard regression and logistic regression analyses showed that higher exposure and diastolic blood pressure were independently associated with longer progression-free and overall survivals and higher probability of partial response in metastatic RCC patients. These findings support axitinib dose titration to increase plasma exposure in patients who tolerate axitinib, and also demonstrate diastolic blood pressure as a potential marker of efficacy., (© The Author(s) 2013.)

Purpose: Axitinib (AG-013736), an oral, potent, and selective inhibitor of vascular endothelial growth factor (VEGF) receptors 1, 2, and 3, is under investigation for treatment of various solid tumors. The safety and pharmacokinetics of axitinib in combination with gemcitabine in patients with advanced pancreatic cancer was evaluated in the phase I portion of this trial. The randomized phase II portion was reported separately., Patients and Methods: Patients with advanced pancreatic cancer who had received no prior chemotherapy were eligible for this study. Pharmacokinetic profiles of the drugs were obtained on cycle (C) 1 day (D) 1 (gemcitabine alone 1,000 mg/m(2)), C1D14 (steady state, axitinib alone 5 mg twice daily [BID]), and C1D15 (gemcitabine plus steady-state axitinib). Adverse events were monitored weekly at the clinic., Results: Eight patients participated in the phase IB portion of the trial. Patients received gemcitabine on D1, D8, and D15 and continuous axitinib in a 28 day-cycle beginning C1D3. There was no dose-limiting toxicity. Common treatment-related adverse events included fatigue, diarrhea, dysphonia, and hypertension. Myelosuppression was similar to gemcitabine monotherapy. No apparent major pharmacokinetic interactions between gemcitabine and axitinib were observed. Of six patients evaluable for efficacy, three had confirmed partial responses., Conclusions: Axitinib (5 mg BID) and gemcitabine (1,000 mg/m(2)) were well tolerated when administered together, without any pharmacokinetic interactions, and showed encouraging antitumor activity.

Purpose: To evaluate the effect of food on axitinib pharmacokinetics in healthy volunteers with two different crystal polymorphs., Methods: Two separate open-label, randomized, single-dose, three-period, crossover trials were conducted. Study I, conducted first using 5-mg axitinib Form IV film-coated immediate-release (FCIR) tablets, enrolled 18 subjects to compare fed versus fasted states and 24 subjects to evaluate the effect of timing of food consumption on axitinib pharmacokinetics. Study II enrolled 30 subjects to assess the effect of food using 5-mg axitinib Form XLI FCIR tablets. Subjects received axitinib after overnight fasting, with limited fasting or, depending on the study design, after consuming high-fat, high-calorie or moderate-fat, standard-calorie meals., Results: For Form IV FCIR, compared with overnight fasting, axitinib plasma exposure [area under the concentration curve (AUC)] was decreased 23 % when administered with food. For Form XLI FCIR, mean axitinib plasma AUC and maximum plasma concentration (C(max)) were 19 and 11 % higher, respectively, with a high-fat, high-calorie meal compared with overnight fasting. When Form XLI FCIR was administered with moderate-fat, standard-calorie meal, AUC and C(max) were 10 and 16 % lower compared with overnight fasting. Both formulations were well tolerated. Adverse events, mostly gastrointestinal (7 % with Form IV FCIR and 13 % with Form XLI FCIR), were mild to moderate in both studies., Conclusions: While axitinib Form IV FCIR was associated with higher plasma exposure after overnight fasting, axitinib Form XLI FCIR can be administered with or without food as differences in axitinib pharmacokinetics under the two conditions were not clinically meaningful.

Purpose: Axitinib, an orally administered inhibitor of vascular endothelial growth factor 1, 2 and 3, is primarily metabolized by cytochrome P450 (CYP) 3A4/5 but is also a substrate for CYP1A2, CYP2C19, UDP-glucuronosyltransferase (UGT)1A1 and the drug transporters P-glycoprotein (encoded by the ABCB1 gene) and OATP1B1 (encoded by SLC01B1). The potential contribution of polymorphisms in genes encoding these enzymes and transporters to axitinib pharmacokinetic variability was assessed., Methods: A fixed effects meta-analysis was performed using data pooled from 11 healthy volunteer clinical pharmacology trials to investigate the potential association between axitinib exposure and major polymorphisms in these genes following a 5-mg dose of axitinib., Results: Up to 15 variant alleles were evaluated and up to 315 healthy volunteers per polymorphism were assayed. None of the polymorphisms analysed was a statistically significant predictor of axitinib pharmacokinetic variability. Amongst genotypes and inferred phenotypes, CYP2C19 genotype and the ABCB1 (G2677T/A) polymorphism were the closest to statistical significance in influencing axitinib pharmacokinetic variability after multiple-testing adjustment. However, no enzyme or transporter genotype/inferred phenotype contributed >5% to the overall pharmacokinetic variability of axitinib., Conclusions: No statistically significant associations between the specific polymorphisms analysed and axitinib plasma exposure were observed, suggesting that genotype- or inferred phenotype-based adjustment of axitinib dose in individual subjects is not warranted.

Objective: Axitinib (AG-013736), an oral, potent, and selective inhibitor of vascular endothelial growth factor receptors 1, 2, and 3, is metabolized primarily by cytochrome P450 (CYP) 3A with minor contributions from CYP1A2, CYP2C19, and glucuronidation. Co-administration with CYP inhibitors may increase systemic exposure to axitinib and alter its safety profile. This study evaluated changes in axitinib plasma pharmacokinetic parameters and assessed safety and tolerability in healthy subjects, following axitinib co-administration with the potent CYP3A inhibitor ketoconazole., Methods: In this randomized, single-blind, two-way crossover study, 32 healthy volunteers received placebo, followed by a single 5-mg oral dose of axitinib, administered either alone or on the fourth day of dosing with oral ketoconazole (400 mg/day for 7 days)., Results: Axitinib exposure was significantly increased in the presence of ketoconazole, with a geometric mean ratio for area under the plasma concentration-time curve from time zero to infinity of 2.06 (90% confidence interval [CI]: 1.84-2.30) and a geometric mean ratio for maximum plasma concentration (C(max)) of 1.50 (90% CI: 1.33-1.70). For axitinib alone or with ketoconazole, C(max) occurred 1.5 and 2.0 h after dosing, respectively. Adverse events were predominantly mild; the most commonly reported treatment-related adverse events were headache and nausea., Conclusions: Axitinib plasma exposures and peak concentrations were increased following concurrent administration of axitinib and ketoconazole in healthy volunteers. Axitinib alone and in combination with ketoconazole was well tolerated. These findings provide an upper exposure for expected axitinib plasma concentrations in the presence of potent metabolic inhibition.

Objective: To evaluate the effects of hepatic impairment on the pharmacokinetics and safety of a single, oral axitinib dose in subjects with mild or moderate hepatic impairment., Methods: In this phase I, open-label, parallel-group study, a total of 24 subjects with either normal hepatic function (n = 8) or with mild (n = 8) or moderate (n = 8) hepatic impairment were administered a single, oral dose of axitinib (5 mg). Blood samples were collected at intervals up to 144 h following dosing, and plasma pharmacokinetics and safety were assessed. Changes in axitinib plasma exposures in subjects with mild or moderate hepatic impairment were predicted using computer simulations and used to guide initial dosing in the clinical study., Results: Axitinib exposure was similar in subjects with normal hepatic function and those with mild hepatic impairment, but approximately twofold higher in subjects with moderate hepatic impairment. Axitinib exposure weakly correlated with measures of hepatic function but was not affected by smoking status. Axitinib protein binding was similar in the three treatment groups. No significant treatment-related adverse events were reported., Conclusions: Compared with subjects with normal hepatic function, moderate hepatic impairment increased axitinib exposure, suggesting that the oral clearance of axitinib is altered in these subjects. In addition, these data indicate a possible need for a dose reduction in subjects who develop moderate or worse hepatic impairment during axitinib treatment. A single 5-mg dose of axitinib was well tolerated in subjects with mild or moderate hepatic impairment.

Background: Axitinib (AG-013736) is a potent and selective oral inhibitor of vascular endothelial growth factor receptors 1, 2, and 3, which have an important role in pancreatic cancer. The aim of this study was to assess the safety and efficacy of gemcitabine plus axitinib versus gemcitabine alone., Methods: Between January and August, 2006, 103 patients with unresectable, locally advanced, or metastatic pancreatic cancer were randomly assigned in a two to one ratio to receive gemcitabine (1000 mg/m(2)) plus axitinib 5 mg twice daily (n=69) or gemcitabine (1000 mg/m(2)) alone (n=34) by a centralised registration system. The primary endpoint was overall survival. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00219557., Findings: All randomised patients were included in the efficacy analyses. Median overall survival was longer with gemcitabine plus axitinib than with gemcitabine alone (6.9 [95% CI 5.3-10.1] months vs 5.6 [3.9-8.8] months). The hazard ratio for survival with gemcitabine plus axitinib versus with gemcitabine alone, adjusted for stratification factors, was 0.71 (95% CI 0.44-1.13). The most common grade 3 or worse adverse events were fatigue (15 [22%] patients in the gemcitabine plus axitinib group vs one [3%] in the gemcitabine alone group), abdominal pain (eight [12%] vs five [16%]), and asthenia (eight [12%] vs one [3%])., Interpretation: Gemcitabine plus axitinib showed a similar safety profile to gemcitabine alone; the small, non-statistically significant gain in overall survival needs to be assessed in a randomised phase III trial.

AG-013736 is an oral anti-angiogenesis agent with activity against a variety of receptor tyrosine kinases, including VEGFR-1, VEGFR-2, VEGFR-3, c-kit, and PDGFR-beta. A phase 2 study was conducted in patients with poor prognosis AML or MDS. Twelve patients (six AML; six MDS) were treated with AG-013736 at a dose of 10mg orally daily for a median of 56 days (range, 1-248 days). Median age was 80 years (range, 58-88 years). Grade 3 or 4 drug-related toxicities included hypertension (42%), mucositis (8%) and deep venous thrombosis (8%). No objective responses occurred; two patients with MDS had stable disease for 8.3 and 6.2 months, respectively. Bone marrow expression of VEGFR-1 and VEGFR-2 was observed in 11% and 0% of patients, respectively. Sustained decreases in soluble VEGFR-2 plasma levels with concomitant elevation in plasma VEGF and placental growth factor levels were obtained during the course of therapy with AG-013736. AG-01736 had minimal biologic or clinical activity in this elderly patient population.

Purpose: We studied the safety, clinical activity, and pharmacokinetics (PK) of AG-013736, an oral receptor tyrosine kinase inhibitor of vascular endothelial cell growth factor, platelet-derived growth factor, and c-Kit, in patients with advanced cancer., Patients and Methods: Patients received fixed doses of AG-013736 orally in 28-day cycles. In the first cohort, patients initially received two single test doses of AG-013736 (10 and 30 mg); subsequent dosing was determined by individual PK parameters. Doses in subsequent cohorts were assigned by using a traditional dose-escalation/de-escalation rule based on observed toxicities in the current and previous cohorts. PK analysis included evaluation of the effect of food and antacid., Results: Thirty-six patients received AG-013736 at doses ranging from 5 to 30 mg by mouth twice daily. The dose-limiting toxicities observed included hypertension, hemoptysis, and stomatitis and were seen primarily at the higher dose levels. The observed hypertension was manageable with medication. Stomatitis was generally tolerable and managed by dose reduction or drug holidays. AG-013736 was absorbed rapidly, with peak plasma concentrations observed within 2 to 6 hours after dosing. The maximum-tolerated dose and recommended phase II dose of AG-013736 is 5 mg, twice daily, administered in the fasted state. No significant drug interaction with antacid was seen. There were three confirmed partial responses and other evidence of clinical activity., Conclusion: In this study, we have demonstrated clinical activity and safety of AG-013736 in patients with advanced solid tumors and identified the dose for phase II testing. The unique phase I study design allowed early identification of important absorption and metabolic issues critical to phase II testing of this agent.