Pharmacokinetic-Interactions of BI 425809, a Novel Glycine Transporter 1 Inhibitor, With Cytochrome P450 and P-Glycoprotein Substrates: Findings From In Vitro Analyses and an Open-Label, Single-Sequence Phase I Study.

PURPOSE/BACKGROUND: Glycine transporter-1 inhibitors may ameliorate cognitive deficits in schizophrenia. This study evaluated potential drug-drug interactions with the glycine transporter-1 inhibitor BI 425809. METHODS/PROCEDURES: Interactions with cytochromes P450 (CYP) and P-glycoprotein (P-gp) were assessed in in vitro assays using human hepatocytes and Caco-2 cells, respectively. Pharmacokinetic characteristics of probe drugs were subsequently assessed in a Phase I, open-label, single-sequence crossover study in healthy male participants. Participants received a probe-drug cocktail containing midazolam (CYP3A4), warfarin (CYP2C9), and omeprazole (CYP2C19) and a separate dose of digoxin (P-gp), alone and on a background of steady-state BI 425809 25 mg once daily in 2 treatment periods. Adverse events were monitored. FINDINGS/RESULTS: In vitro assays revealed concentration-dependent induction of CYP3A4 and inhibition of P-gp by BI 425809. In the clinical study, 12 of 13 participants completed both periods. With BI 425809, area under the plasma concentration curve from administration to the last measurement (AUC 0-tz ) and maximum plasma concentration ( Cmax ) for midazolam were lower than when administered alone. Adjusted geometric mean ratios (90% confidence interval) were 70.6% (63.9%-78.1%) for AUC 0-tz and 77.6% (67.3%-89.4%) for Cmax . For warfarin and digoxin, AUC 0-tz and Cmax were similar with and without BI 425809. For omeprazole, BI 425809 slightly reduced AUC 0-tz but not Cmax versus omeprazole alone. No new safety signals were identified. IMPLICATIONS/CONCLUSIONS: These findings indicate induction of CYP3A4 by once-daily BI 425809 25 mg (the assumed highest therapeutic dose) and no meaningful effects on CYP2C9, CYP2C19, or P-gp in vivo.

Effects of Cytochrome P450 3A4 Induction and Inhibition on the Pharmacokinetics of BI 425809, a Novel Glycine Transporter 1 Inhibitor.

BACKGROUND AND OBJECTIVE: Increased glycine availability at the synaptic cleft may enhance N-methyl-D-aspartate receptor signalling and provide a promising therapeutic strategy for cognitive impairment associated with schizophrenia. These studies aimed to assess the pharmacokinetics of BI 425809, a potent glycine-transporter-1 inhibitor, when co-administered with a strong cytochrome P450 3A4 (CYP3A4) inhibitor (itraconazole) and inducer (rifampicin). METHODS: In vitro studies using recombinant CYPs, human liver microsomes, and human hepatocytes were conducted to determine the CYP isoforms responsible for BI 425809 metabolism. In addition, two open-label, fixed-treatment period, phase I studies in healthy male volunteers are described. Period 1: participants received oral BI 425809 25 mg (single dose) on day 1; period 2: participants received multiple doses, across 10 days, of oral itraconazole or rifampicin combined with a single dose of oral BI 425809 25 mg on day 4/7 of the itraconazole/rifampicin treatment, respectively. Pharmacokinetic and safety endpoints were assessed in the absence/presence of itraconazole/rifampicin and included area under the concentration-time curve (AUC) over the time interval 0-167 h (AUC0‒167; itraconazole), 0-168 h (AUC0‒168; rifampicin), or 0-infinity (AUC0-∞; rifampicin and itraconazole), maximum measured concentration (Cmax) of BI 425809, and adverse events. RESULTS: In vitro results suggested that CYP3A4 accounted for ≥ 90% of the metabolism of BI 425809. BI 425809 exposure (adjusted geometric mean ratio [%]) was higher in the presence of itraconazole (AUC0‒167: 265.3; AUC0-∞: 597.0; Cmax: 116.1) and lower in the presence of rifampicin (AUC0‒168: 10.3; AUC0-∞: 9.8; Cmax: 37.4) compared with BI 425809 alone. Investigational treatments were well tolerated. CONCLUSIONS: Systemic exposure of BI 425809 was altered in the presence of strong CYP3A4 modulators, corroborating in vitro results that CYP3A4 mediates a major metabolic pathway for BI 425809. TRIAL REGISTRATION NUMBER: NCT02342717 (registered on 15 January 2015) and NCT03082183 (registered on 10 March 2017).

A Drug-Drug Interaction Study to Investigate the Effect of Nintedanib on the Pharmacokinetics of Microgynon (Ethinylestradiol and Levonorgestrel) in Female Patients with Systemic Sclerosis-Associated Interstitial Lung Disease.

BACKGROUND AND OBJECTIVES: Nintedanib is a tyrosine kinase inhibitor approved for the treatment of systemic sclerosis-associated interstitial lung disease (SSc-ILD), idiopathic pulmonary fibrosis, and other chronic fibrosing ILDs with a progressive phenotype. As nintedanib may cause foetal harm, patients taking nintedanib should avoid pregnancy. The objective of this study was to investigate the effect of nintedanib co-administration on the pharmacokinetics of Microgynon (ethinylestradiol and levonorgestrel) in female patients with SSc-ILD. METHODS: This was an open-label, two-period, fixed-sequence, drug-drug interaction study. Female patients with SSc and ≥ 10% extent of fibrotic ILD on a high-resolution computed tomography scan were eligible to participate. In Period 1, patients received one Microgynon tablet (ethinylestradiol 30 µg and levonorgestrel 150 µg) ≥ 3 days before the first administration of nintedanib in Period 2. In Period 2, patients received one Microgynon tablet following intake of nintedanib 150 mg twice daily for ≥ 10 consecutive days. The primary pharmacokinetic endpoints were the areas under the plasma concentration-time curve of ethinylestradiol and levonorgestrel over the time interval from 0 to the last quantifiable data point (AUC0-tz) and the maximum measured concentrations of ethinylestradiol and levonorgestrel in plasma (Cmax). The secondary pharmacokinetic endpoint was the area under the plasma concentration-time curve of ethinylestradiol and levonorgestrel over the time interval from 0 extrapolated to infinity (AUC0-∞). The relative exposures of ethinylestradiol and levonorgestrel when administered alone and in combination with nintedanib were assessed using an ANOVA model. RESULTS: Seventeen patients were treated. Pharmacokinetic data from 15 patients were analysed. Plasma concentration-time profiles of ethinylestradiol and levonorgestrel were similar following administration of Microgynon before and after administration of nintedanib for ≥ 10 consecutive days. Adjusted geometric mean (gMean) ratios [90% confidence intervals (CIs)] for AUC0‒tz (101.4% [92.8, 110.7]) and AUC0‒∞ (101.2% [94.0, 109.1]) indicated that there was no difference in total ethinylestradiol exposure when Microgynon was administered before or after administration of nintedanib. The adjusted gMean ratio for Cmax of ethinylestradiol (116.7% [90% CI 107.6, 126.5]) indicated an increase in peak exposure in the presence of nintedanib. Adjusted gMean ratios [90% CIs] for AUC0-tz (96.4% [91.5, 101.6]) and Cmax (100.9% [89.9, 113.2]) indicated that there was no difference in total or peak levonorgestrel exposure when Microgynon was administered before or after administration of nintedanib. The adjusted gMean ratio for AUC0‒∞ of levonorgestrel indicated a decrease in total exposure in the presence of nintedanib (88.1% [90% CI 80.0, 97.0]). CONCLUSION: Pharmacokinetic data indicate that there is no relevant effect of nintedanib on plasma exposure to ethinylestradiol and levonorgestrel in female patients with SSc-ILD. TRIAL REGISTRATION: Clinicaltrials.gov NCT03675581.

Clinical Pharmacokinetics and Pharmacodynamics of Nintedanib.

Nintedanib is an oral, small-molecule tyrosine kinase inhibitor approved for the treatment of idiopathic pulmonary fibrosis and patients with advanced non-small cell cancer of adenocarcinoma tumour histology. Nintedanib competitively binds to the kinase domains of vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF) and fibroblast growth factor (FGF). Studies in healthy volunteers and in patients with advanced cancer have shown that nintedanib has time-independent pharmacokinetic characteristics. Maximum plasma concentrations of nintedanib are reached approximately 2-4 h after oral administration and thereafter decline at least bi-exponentially. Over the investigated dose range of 50-450 mg once daily and 150-300 mg twice daily, nintedanib exposure increases are dose proportional. Nintedanib is metabolised via hydrolytic ester cleavage, resulting in the formation of the free acid moiety that is subsequently glucuronidated and excreted in the faeces. Less than 1% of drug-related radioactivity is eliminated in urine. The terminal elimination half-life of nintedanib is about 10-15 h. Accumulation after repeated twice-daily dosing is negligible. Sex and renal function have no influence on nintedanib pharmacokinetics, while effects of ethnicity, low body weight, older age and smoking are within the inter-patient variability range of nintedanib exposure and no dose adjustments are required. Administration of nintedanib in patients with moderate or severe hepatic impairment is not recommended, and patients with mild hepatic impairment should be monitored closely and the dose adjusted accordingly. Nintedanib has a low potential for drug-drug interactions, especially with drugs metabolised by cytochrome P450 enzymes. Concomitant treatment with potent inhibitors or inducers of the P-glycoprotein transporter can affect the pharmacokinetics of nintedanib. At an investigated dose of 200 mg twice daily, nintedanib does not have proarrhythmic potential.

No relevant pharmacokinetic drug-drug interaction between nintedanib and pirfenidone.

Nintedanib and pirfenidone are approved treatments for idiopathic pulmonary fibrosis (IPF). This open-label, two-group trial investigated the pharmacokinetic drug-drug interaction between these two drugs in patients with IPF.Subjects not treated with antifibrotics at screening (group 1, n=20) received a single nintedanib dose (150 mg) followed by pirfenidone (titrated to 801 mg thrice daily) for 3 weeks, with a further single nintedanib dose (150 mg) on the last day (day 23). Subjects treated with pirfenidone at screening (group 2, n=17) continued to receive pirfenidone alone (801 mg thrice daily) for 7 days, then co-administered with nintedanib (150 mg twice daily) for a further 7 days, before single doses of both treatments on day 16.In group 1, adjusted geometric mean (gMean) ratios (with/without pirfenidone) were 88.6% and 80.6% for nintedanib area under the plasma concentration-time curve (AUC) and maximum plasma concentration (Cmax), respectively. In group 2, gMean ratios (with/without nintedanib) were 97.2% and 99.5% for pirfenidone AUC and Cmax, respectively. For all parameters, the 90% confidence intervals included 100%, suggesting similar exposure for administration alone and when co-administered. Both treatments were well tolerated.These data indicate there is no relevant pharmacokinetic drug-drug interaction between nintedanib and pirfenidone when co-administered in IPF patients.

Evaluation of Pharmacokinetics and Pharmacodynamics of BI 425809, a Novel GlyT1 Inhibitor: Translational Studies.

BI 425809 is a potent and selective glycine transporter 1 (GlyT1) inhibitor being developed for the treatment of cognitive impairment in Alzheimer disease and schizophrenia. Translational studies evaluated the effects of BI 425809 on glycine levels in rat and human cerebrospinal fluid (CSF). Oral administration of BI 425809 in rats induced a dose-dependent increase of glycine CSF levels from 30% (0.2 mg/kg, not significant) to 78% (2 mg/kg, P < 0.01), relative to vehicle. Similarly, oral administration of BI 425809 in healthy volunteers resulted in a dose-dependent increase in glycine CSF levels at steady state, with a mean 50% increase at doses as low as 10 mg. The peak plasma concentration (Cmax ) of BI 425809 was achieved earlier in plasma than in CSF (tmax 3-5 vs. 5-8 hours, respectively). Generally, BI 425809 was safe and well tolerated. These data provide evidence of functional target engagement of GlyT1 by BI 425809.

Multiple Rising Doses of Oral BI 425809, a GlyT1 Inhibitor, in Young and Elderly Healthy Volunteers: A Randomised, Double-Blind, Phase I Study Investigating Safety and Pharmacokinetics.

BACKGROUND AND OBJECTIVE: Schizophrenia and Alzheimer's disease are characterised by abnormalities in glutamatergic pathways related to N-methyl-D-aspartate receptor hypofunction. Glycine is an N-methyl-D-aspartate receptor co-agonist; inhibition of glycine transporter 1 may improve N-methyl-D-aspartate receptor function. This phase I, randomised, two-part study evaluated the safety, tolerability and pharmacokinetic profile of BI 425809, a novel glycine transporter 1 inhibitor, in healthy male and female volunteers. METHODS: Part 1 evaluated BI 425809 10, 25, 50 or 75 mg once daily or 75 mg twice daily in young subjects, and 25 mg or 50 mg once daily in elderly subjects. Each dose group comprised 12 subjects who received BI 425809 (n = 9) or placebo (n = 3) for 14 days (day 1: single dose; days 4-14: multiple dosing). Part 2 compared pharmacokinetic profiles in 12 subjects who received a single dose of BI 425809 25 mg in the morning and evening. RESULTS: Pharmacokinetic profiles were similarly shaped for all dose groups. Median time to maximum plasma concentration was 3.0-4.5 h with steady state being reached between days 6 and 10. Pharmacokinetic parameters demonstrated dose linearity at the predicted therapeutic exposure range of BI 425809 ≤ 25 mg once daily, but increased less than dose proportionally for ≥ 50 mg once daily. All reported adverse events were of mild-to-moderate intensity, 51/84 (61%; part 1) subjects had one or more treatment-related adverse event, no serious adverse events occurred and no dose dependency was observed. CONCLUSIONS: Pharmacokinetic properties support both morning and evening dosing. BI 425809 was generally well tolerated at all tested doses. CLINICALTRIALS. GOV IDENTIFIER: NCT02337283.

Safety, Tolerability and Pharmacokinetics of Oral BI 425809, a Glycine Transporter 1 Inhibitor, in Healthy Male Volunteers: A Partially Randomised, Single-Blind, Placebo-Controlled, First-in-Human Study.

BACKGROUND AND OBJECTIVES: Schizophrenia and Alzheimer's disease are characterised by glutamatergic pathway abnormalities related to N-methyl-D-aspartate (NMDA) receptor hypofunction and cognitive impairment. Glycine is an NMDA receptor co-agonist; inhibition of glycine transporter 1 (GlyT1) should improve NMDA receptor hypofunction. This study evaluated safety and pharmacokinetic properties of BI 425809-a potent and selective GlyT1 inhibitor. METHODS: In the single-rising dose (SRD) component of this study, subjects were randomised to a single dose of BI 425809 [doses (mg): 0.5, 1, 2, 5, 10, 25, 50, 100 and 150], or placebo. The bioavailability/food effect (BA/FE) component investigated BI 425809 pharmacokinetics following single dosing (25-mg tablet) after overnight fasting or with a high-calorie meal or as solution (25 mg) after overnight fasting. RESULTS: Overall, 33/83 (39.8%) subjects had ≥ 1 treatment-related adverse event (AE); there were no deaths or serious AEs. Reported SRD part AEs trended towards dose dependency, occurring at the higher doses (mostly central nervous system related). BI 425809 plasma concentration-time profiles were similarly shaped across all doses and plasma exposure increased proportional to dose. In the BA/FE component, geometric mean ratios for the area under the concentration-time curve from time zero to the last measurable concentration and the maximum plasma concentration for tablet fasted versus solution fasted were 80.5 and 50.0%, respectively, and for tablet fed versus fasted were 125.9 and 142.1%, respectively. CONCLUSION: BI 425809 was generally well-tolerated at doses expected to be clinically relevant. The AE profile suggested possible GlyT1-inhibiting effects. CLINICAL TRIAL IDENTIFIER: NCT02068690.

Clinical Pharmacokinetics and Pharmacodynamics of Afatinib.

Afatinib is an oral, irreversible ErbB family blocker that covalently binds to the kinase domains of epidermal growth factor receptor (EGFR), human EGFRs (HER) 2, and HER4, resulting in irreversible inhibition of tyrosine kinase autophosphorylation. Studies in healthy volunteers and patients with advanced solid tumours have shown that once-daily afatinib has time-independent pharmacokinetic characteristics. Maximum plasma concentrations of afatinib are reached approximately 2-5 h after oral administration and thereafter decline, at least bi-exponentially. Food reduces total exposure to afatinib. Over the clinical dose range of 20-50 mg, afatinib exposure increases slightly more than dose proportional. Afatinib metabolism is minimal, with unchanged drug predominantly excreted in the faeces and approximately 5 % in urine. Apart from the parent drug afatinib, the major circulation species in human plasma are the covalently bound adducts to plasma protein. The effective elimination half-life is approximately 37 h, consistent with an accumulation of drug exposure by 2.5- to 3.4-fold based on area under the plasma concentration-time curve (AUC) after multiple dosing. The pharmacokinetic profile of afatinib is consistent across a range of patient populations. Age, ethnicity, smoking status and hepatic function had no influence on afatinib pharmacokinetics, while females and patients with low body weight had increased exposure to afatinib. Renal function is correlated with afatinib exposure, but, as for sex and body weight, the effect size for patients with severe renal impairment (approximately 50 % increase in AUC) is only mildly relative to the extent of unexplained interpatient variability in afatinib exposure. Afatinib has a low potential as a victim or perpetrator of drug-drug interactions, especially with cytochrome P450-modulating agents. However, concomitant treatment with potent inhibitors or inducers of the P-glycoprotein transporter can affect the pharmacokinetics of afatinib. At a dose of 50 mg, afatinib does not have proarrhythmic potential.

Influence of Renal Impairment on the Pharmacokinetics of Afatinib: An Open-Label, Single-Dose Study.

BACKGROUND AND OBJECTIVE: Afatinib is an oral irreversible ErbB-Family Blocker indicated for treatment of patients with EGFR mutation positive advanced non-small cell lung cancer. This trial assessed whether renal impairment influences the pharmacokinetics and safety of afatinib. METHODS: This was an open-label, single-dose study. Pharmacokinetic parameters after afatinib 40 mg were investigated in subjects with moderate (n = 8) or severe (n = 8) renal impairment (estimated glomerular filtration rate 30-59 mL/min/1.73 m2 and 15-29 mL/min/1.73 m2, respectively) and healthy matched controls (n = 14). Plasma and urine samples were collected before and up to 14 days after dosing for pharmacokinetic and plasma protein-binding assessment. Primary endpoints were area under the plasma concentration-time curve from time zero to the last quantifiable concentration (AUClast) and maximum plasma concentration (C max) between subjects with renal impairment and healthy matched controls. RESULTS: Pharmacokinetic profiles and plasma protein binding were similar in all groups. The extent of exposure, as indicated by AUClast and C max, was generally similar between the matched treatment groups, with the exception of the geometric mean ratio of AUClast for subjects with severe renal impairment, which showed a trend towards a higher value compared with matched healthy subjects (150.0 % [90 % CI 105.3-213.7]) Inter-individual variability was moderate (geometric mean coefficient of variation 28-39 % for moderate impairment, 34-42 % for severe impairment). Afatinib was well tolerated and urinary excretion was minimal. CONCLUSION: Moderate-to-severe renal impairment had a minor influence on the pharmacokinetics of afatinib that was within the observed inter-individual variability, suggesting that afatinib treatment can be considered in this patient population. Registered at ClinicalTrials.gov as NCT02096718.

A phase II study of afatinib, an irreversible ErbB family blocker, added to letrozole in patients with estrogen receptor-positive hormone-refractory metastatic breast cancer progressing on letrozole.

UNLABELLED: Phase II, open-label study assessing the efficacy and safety of the ErbB family blocker afatinib combined with letrozole in estrogen receptor-positive metastatic breast cancer (MBC) patients who had progressed on letrozole monotherapy. Adult females (N = 28) received oral afatinib (50 [n = 7], 40 [n = 13] or 30 [n = 8] mg/day) plus letrozole 2.5 mg/day in 28-day cycles until disease progression. Primary endpoint was the progression-free rate at or after 16 weeks of afatinib. At 16 weeks, four patients remained on afatinib without progression; two of these were HER2 negative. Fifteen (54 %) patients had a best response of stable disease according to Response Evaluation Criteria in Solid Tumors. Median progression-free survival was 60, 107 and 79 days with 50, 40 and 30 mg/day afatinib, respectively. Diarrhea, asthenia, rash, mucosal inflammation and nausea were the most frequent adverse events. In this small, exploratory study, afatinib combined with letrozole was able to induce disease stabilization in 54 % of hormone-refractory MBC patients previously progressing on letrozole. CLINICAL TRIAL REGISTRATION: NCT00708214.

A Phase I dose-escalation study of afatinib combined with nintedanib in patients with advanced solid tumors.

AIMS: To evaluate the safety and maximum tolerated dose (MTD) of afatinib combined with nintedanib. MATERIALS & METHODS: Patients received afatinib 10-20 mg daily plus nintedanib 150-200 mg twice daily (28-day cycle). Dose escalation followed a 3+3 design. RESULTS: Patients received afatinib/nintedanib: 10/150 mg (n = 11); 10/200 mg (n = 13; MTD); 20/200 mg (n = 4). Four patients had dose-limiting toxicities (all grade 3): increased alanine aminotransferase (afatinib/nintedanib: 10/150 mg), diarrhea (10/200 mg), dehydration (20/200 mg), diarrhea with elevated liver enzymes (20/200 mg). Frequent treatment-related adverse events were diarrhea, nausea, anorexia, fatigue and vomiting. In total, 14 patients (46.2%) had objective responses at the MTD. CONCLUSION: The MTD, afatinib 10 mg daily plus nintedanib 200 mg twice daily, had a manageable safety profile, but was considered subtherapeutic for Phase II evaluation.

Phase I/randomized phase II study of afatinib, an irreversible ErbB family blocker, with or without protracted temozolomide in adults with recurrent glioblastoma.

BACKGROUND: This phase I/II trial evaluated the maximum tolerated dose (MTD) and pharmacokinetics of afatinib plus temozolomide as well as the efficacy and safety of afatinib as monotherapy (A) or with temozolomide (AT) vs temozolomide monotherapy (T) in patients with recurrent glioblastoma (GBM). METHODS: Phase I followed a traditional 3 + 3 dose-escalation design to determine MTD. Treatment cohorts were: afatinib 20, 40, and 50 mg/day (plus temozolomide 75 mg/m(2)/day for 21 days per 28-day cycle). In phase II, participants were randomized (stratified by age and KPS) to receive A, T or AT; A was dosed at 40 mg/day and T at 75 mg/m(2) for 21 of 28 days. Primary endpoint was progression-free survival rate at 6 months (PFS-6). Participants were treated until intolerable adverse events (AEs) or disease progression. RESULTS: Recommended phase II dose was 40 mg/day (A) + T based on safety data from phase I (n = 32). Most frequent AEs in phase II (n = 119) were diarrhea (71% [A], 82% [AT]) and rash (71% [A] and 69% [AT]). Afatinib and temozolomide pharmacokinetics were unaffected by coadministration. Independently assessed PFS-6 rate was 3% (A), 10% (AT), and 23% (T). Median PFS was longer in afatinib-treated participants with epidermal growth factor receptor (EFGR) vIII-positive tumors versus EGFRvIII-negative tumors. Best overall response included partial response in 1 (A), 2 (AT), and 4 (T) participants and stable disease in 14 (A), 14 (AT), and 21 (T) participants. CONCLUSIONS: Afatinib has a manageable safety profile but limited single-agent activity in unselected recurrent GBM patients.

Pharmacokinetics of afatinib in subjects with mild or moderate hepatic impairment.

PURPOSE: Afatinib, an oral irreversible ErbB family blocker, undergoes minimal metabolism by non-enzyme-catalysed adduct formation with proteins or nucleophilic small molecules and is predominantly non-renally excreted via the entero-hepatic system. This trial assessed whether mild or moderate hepatic impairment influences the pharmacokinetics of afatinib. METHODS: This was an open-label single-dose study. Pharmacokinetic parameters after afatinib 50 mg were investigated in subjects with mild (n = 8) or moderate (n = 8) hepatic impairment (Child-Pugh A and B) and healthy controls (n = 16) matched for age, weight and gender. Plasma and urine samples for pharmacokinetic assessment were collected before and up to 10 days after dosing. Additional blood samples were drawn to determine ex vivo plasma protein binding of afatinib. Primary endpoints were comparisons of afatinib C max and AUC0-∞ between subjects with hepatic impairment and healthy matched controls. Study progression was based on drug-related toxicity (CTCAE v. 3.0) and C max of afatinib. RESULTS: Afatinib pharmacokinetic profiles and plasma protein binding were similar in subjects with impaired liver function and healthy controls. Compared with matched controls, the afatinib-adjusted geometric mean ratio for AUC0-∞ was 92.6% (90% CI 68.0-126.3%) and Cmax was 109.5% (90% CI 82.7-144.9%) for subjects with mild hepatic impairment, and 94.9% (90% CI 72.3-124.5%) and 126.9% (90% CI 86.0-187.2%), respectively, for subjects with moderate hepatic impairment. For all parameters, the 90% CI included 100%. Afatinib was generally well tolerated with no serious adverse events reported. CONCLUSION: Mild to moderate hepatic impairment had no clinically relevant effect on the pharmacokinetics of a single 50 mg dose of afatinib, implying that adjustments to the starting dose of afatinib are not considered necessary in this patient population.

Population pharmacokinetics of afatinib, an irreversible ErbB family blocker, in patients with various solid tumors.

PURPOSE: This population pharmacokinetic model was developed to characterize the pharmacokinetics of the oral irreversible ErbB family blocker afatinib in patients with solid tumors and to investigate the impact of selected intrinsic and extrinsic factors. METHODS: Data from 927 patients (4,460 plasma concentrations) with advanced solid tumors in 7 Phase II or III studies were analyzed. Afatinib was administered orally in continuous 3 or 4 week cycles (starting dose 20, 40 or 50 mg once-daily). Plasma concentration-time data for up to 7 months dosing were analyzed using nonlinear mixed-effects modeling. RESULTS: The pharmacokinetic profile of afatinib was best described by a two-compartment disposition model with first-order absorption and linear elimination. There was a slightly more than proportional increase in exposure with increasing dose, accounted for by a dose-dependent relative bioavailability. For the therapeutic dose of 40 mg, the estimated apparent total clearance and distribution volume at steady state were 734 mL/min and 2,370 L, respectively. While food intake, body weight, gender, Eastern Cooperative Oncology Group performance score, renal function, and the level of alkaline phosphatase, lactate dehydrogenase or total protein were statistically significant covariates influencing afatinib exposure, none resulted in a proportional change in exposure of more than 27.8 % in a typical patient at model extremes (2.5th and 97.5th percentiles of baseline values for continuous covariates). In simulations of the individual covariate effects, none caused a change in the typical profile exceeding the observed variability range (90 % prediction interval) of afatinib. CONCLUSION: This population pharmacokinetic model adequately described the pharmacokinetics of afatinib in different cancer patient populations and therefore can be used for simulations exploring covariate effects and possible dose adaptations. The effect size for each of the individual covariates is not considered clinically relevant.

Pharmacokinetic drug interactions of afatinib with rifampicin and ritonavir.

BACKGROUND AND OBJECTIVE: Afatinib is a potent, irreversible, ErbB family blocker in clinical development for the treatment of advanced non-small cell lung cancer, metastatic head and neck cancer, and other solid tumours. As afatinib is a substrate for the P-glycoprotein (P-gp) pump transporter the three studies presented here investigated the pharmacokinetics of afatinib in the presence of a potent inhibitor (ritonavir) or inducer [rifampicin (rifampin)] of P-gp. METHODS: We conducted phase I, open-label, single-centre studies in healthy male volunteers who received a single once-daily oral dose of afatinib (20 or 40 mg) together with either ritonavir or rifampicin; two studies had a randomised, two- and three-way crossover design and the third was a non-randomised, two-period sequential study. RESULTS: When afatinib 20 mg was administered 1 h after ritonavir, afatinib geometric mean (gMean) maximum plasma concentration (C max) and area under the plasma concentration-time curve from time zero to infinity (AUC∞) increased by 38.5 and 47.6 %, respectively. Coadministration of ritonavir either simultaneously or 6 h later than afatinib 40 mg resulted in minimal increase in the afatinib gMean C max and AUC∞ (4.1 and 18.6 % for simultaneous administration with AUC∞ not completely within the bioequivalence limits; 5.1 and 10.8 % for timed administration within the bioequivalence limits). Administration of afatinib 40 mg in the presence of rifampicin led to reduction in C max and AUC∞ by 21.6 and 33.8 %, respectively. In all studies, P-gp modulation mainly affected the extent of absorption of afatinib; there was no change in the terminal elimination half-life. The overall safety profile of afatinib was acceptable. CONCLUSION: Coadministration of potent P-gp modulators had no clinically relevant effect on afatinib exposure. Effects of potent P-gp inhibitors were minimal at higher afatinib doses and can be readily managed by the timing of concomitant therapy. As afatinib is not a relevant modulator or substrate of cytochrome P450 enzymes, the drug-drug interaction potential is considered to be low.

Pharmacokinetics of afatinib, a selective irreversible ErbB family blocker, in patients with advanced solid tumours.

BACKGROUND AND OBJECTIVE: Afatinib is a potent, irreversible, ErbB family blocker in clinical development for the treatment of a variety of solid tumours. This study evaluated the pharmacokinetics of afatinib (10-100 mg once daily) in cancer patients. METHODS: Data from 221 patients with advanced solid tumours in four phase I and one phase II trial were analysed using non-compartmental methods. RESULTS: Within each dose group, the shape of the geometric mean plasma concentration-time profiles after single and multiple doses were comparable. Maximum plasma concentration (C(max)) values were achieved 2-5 h after dosing and thereafter declined at least bi-exponentially. Steady-state plasma concentrations were attained within 8 days after the start of dosing. The geometric mean terminal elimination half-life at steady state was about 37 h. Repeated dosing resulted in a 2.77-fold accumulation based on the area under the plasma concentration-time curve (AUC), and 2.11-fold accumulation based on C(max) values. A slightly more than dose-proportional increase in afatinib exposure was observed. There was moderate intra-individual variability in afatinib trough concentration values (the geometric coefficient of variation (gCV) ranged from 22.2 to 67.5 %). The inter-patient variability in plasma concentrations was moderate to high (e.g. at the 40 mg dose, the gCVs ranged from 35.6 to 221 %). The exposure to afatinib (as measured by AUC and C(max)) correlated with the severity of the most common adverse events of afatinib--diarrhoea and rash. CONCLUSION: The pharmacokinetic profile of afatinib supports a once-daily dosage regimen. As expected for this patient population, the pharmacokinetic parameters of afatinib showed moderate to high inter-patient variability. Afatinib exhibits non-linear pharmacokinetics.

A phase II trial to assess efficacy and safety of afatinib in extensively pretreated patients with HER2-negative metastatic breast cancer.

Afatinib (BIBW 2992) is an ErbB-family blocker that irreversibly inhibits signaling from all relevant ErbB-family dimers. Afatinib has demonstrated preclinical activity in human epidermal growth factor receptor HER2 (ErbB2)-positive and triple-negative xenograft models of breast cancer, and clinical activity in phase I studies. This was a multicenter phase II study enrolling patients with HER2-negative metastatic breast cancer progressing following no more than three lines of chemotherapy. No prior epidermal growth factor receptor-targeted therapy was allowed. Patients received 50-mg afatinib once daily until disease progression. Tumor assessment was performed at every other 28-day treatment course. The primary endpoint was clinical benefit (CB) for ≥4 treatment courses in triple-negative (Cohort A) metastatic breast cancer (TNBC) and objective responses measured by Response Evaluation Criteria in Solid Tumors in patients with HER2-negative, estrogen receptor-positive, and/or progesterone receptor-positive breast cancer (Cohort B). Fifty patients received treatment, including 29 patients in Cohort A and 21 patients in Cohort B. No objective responses were observed in either cohort. Median progression-free survival was 7.4 and 7.7 weeks in Cohorts A and B, respectively. Three patients with TNBC had stable disease for ≥4 treatment courses, one of them for 12 courses (median 26.3 weeks; range 18.9-47.9 weeks). The most frequently observed afatinib-associated adverse events (AEs) were gastrointestinal and skin-related side effects, which were manageable by symptomatic treatment and dose reductions. Afatinib pharmacokinetics were comparable to those observed in previously reported phase I trials. In conclusion, afatinib had limited activity in HER2-negative breast cancer. AEs were generally manageable and mainly affected the skin and the gastrointestinal tract.

A phase II study of afatinib (BIBW 2992), an irreversible ErbB family blocker, in patients with HER2-positive metastatic breast cancer progressing after trastuzumab.

Afatinib is an oral, ErbB family blocker, which covalently binds and irreversibly blocks all kinase-competent ErbB family members. This phase II, open-label, single-arm study explored afatinib activity in human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients progressing after trastuzumab treatment. Patients had stage IIIB/IV HER2-positive metastatic breast cancer, with progression following trastuzumab or trastuzumab intolerance and an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2. Patients received 50 mg afatinib once-daily until disease progression. Primary endpoint was objective response rate (Response Evaluation Criteria in Solid Tumors 1.0), with tumor assessments every 8 weeks. Forty-one patients were treated. Patients had received a median of three prior chemotherapy lines (range, 0-15) and 68.3% had received trastuzumab for >1 year. Four patients (10% of 41 treated; 11% of evaluable patients) had partial response. Fifteen patients (37% of 41) had stable disease as best response and 19 (46% of 41) achieved clinical benefit. Median progression-free survival was 15.1 weeks (95% confidence interval [CI]: 8.1-16.7); median overall survival was 61.0 weeks (95% CI: 56.7-not evaluable). Most frequent common terminology criteria for adverse events grade 3 treatment-related adverse events were diarrhea (24.4%) and rash (9.8%). Afatinib monotherapy was associated with promising clinical activity in extensively pretreated HER2-positive breast cancer patients who had progressed following trastuzumab treatment.

Oxidative stress and endothelial dysfunction in aortas of aged spontaneously hypertensive rats by NOX1/2 is reversed by NADPH oxidase inhibition.

Arterial hypertension is associated with increased levels of reactive oxygen species, which may scavenge endothelium-derived NO and thereby diminish its vasorelaxant effects. However, the quantitatively relevant source of reactive oxygen species is unclear. Thus, this potential pathomechanism is not yet pharmacologically targetable. Several enzymatic sources of reactive oxygen species have been suggested: uncoupled endothelial NO synthase, xanthine oxidase, and NADPH oxidases. Here we show that increased reactive oxygen species formation in aortas of 12- to 14-month-old spontaneously hypertensive rats versus age-matched Wistar Kyoto rats is inhibited by the specific NADPH oxidase inhibitor VAS2870 but neither by the xanthine oxidase inhibitor oxypurinol nor the NO synthase inhibitor N(G)-nitro-l-arginine methyl ester. NADPH oxidase activity, as well as protein expression of its catalytic subunits, NOX1 and NOX2, was increased in the aortas of spontaneously hypertensive rats, whereas the expression of NOX4 protein, the most abundant NOX isoform, was not significantly changed. Impaired acetylcholine-induced relaxation of spontaneously hypertensive rat aortas was significantly improved by VAS2870. In conclusion, NOX1 and NOX2 but not NOX4 proteins are increased in aged spontaneously hypertensive rat aortas. Importantly, these NOX isoforms, in particular, ectopic expression of NOX1 in endothelial cells, appear to affect vascular function in an NADPH oxidase inhibitor-reversible manner. NADPH oxidases may, thus, be a novel target for the treatment of systemic hypertension.