Effect of Roxadustat on the Pharmacokinetics of Simvastatin, Rosuvastatin, and Atorvastatin in Healthy Subjects: Results From 3 Phase 1, Open-Label, 1-Sequence, Crossover Studies.

Roxadustat inhibits breast cancer resistance protein and organic anion transporting polypeptide 1B1, which can affect coadministered statin concentrations. Three open-label, 1-sequence crossover phase 1 studies in healthy subjects were conducted to assess effects from steady-state 200-mg roxadustat on pharmacokinetics and tolerability of 40-mg simvastatin (CL-0537 and CL-0541), 40-mg atorvastatin (CL-0538), or 10-mg rosuvastatin (CL-0537). Statins were dosed concomitantly with roxadustat in 28 (CL-0537) and 24 (CL-0538) healthy subjects, resulting in increases of maximum plasma concentration (Cmax ) and area under the plasma concentration-time curve from the time of dosing extrapolated to infinity (AUCinf ) 1.87- and 1.75-fold for simvastatin, 2.76- and 1.85-fold for simvastatin acid, 4.47- and 2.93-fold for rosuvastatin, and 1.34- and 1.96-fold for atorvastatin, respectively. Additionally, simvastatin dosed 2 hours before, and 4 and 10 hours after roxadustat in 28 (CL-0541) healthy subjects, resulted in increases of Cmax and AUCinf 2.32- to 3.10-fold and 1.56- to 1.74-fold for simvastatin and 2.34- to 5.98-fold and 1.89- to 3.42-fold for simvastatin acid, respectively. These increases were not attenuated by time-separated statin dosing. No clinically relevant differences were observed for terminal elimination half-life. Concomitant 200-mg roxadustat and a statin was generally well tolerated during the study period. Roxadustat effects on statin Cmax and AUCinf were statin and administration time dependent. When coadministered with roxadustat, statin-associated adverse reactions and the need for statin dose reduction should be evaluated.

Population pharmacokinetics of roxadustat in Japanese dialysis-dependent chronic kidney disease patients with anaemia.

AIMS: Our objective was to develop a population pharmacokinetic (PK) model to describe roxadustat plasma concentrations in Japanese dialysis-dependent chronic kidney disease (DD-CKD) patients with renal anaemia and to identify the covariate factors that affect exposure of roxadustat. METHODS: In total, 367 patients (male, 256; female, 111) contributing 1285 concentration values from 4 clinical studies were analysed using a nonlinear mixed-effects modelling approach. Candidate covariates included clinical characteristics hypothesized to affect roxadustat clearance and bioavailability, such as demographics, hepatic parameters and concomitant drugs. RESULTS: The roxadustat PK data in Japanese DD-CKD patients with renal anaemia were well described by a 2-compartment disposition model with first-order absorption and interindividual variability on clearance, central volume of distribution and absorption rate constant. Age was identified as a significant covariate on clearance. PK profiles of haemodialysis and peritoneal dialysis patients were comparable. Eighty-two percent of patients were administered at least 1 phosphate binder (PB). The effect of PBs on roxadustat concentration was modelled as a decrease in bioavailability. Staggered administration of PBs reduced the effect on roxadustat bioavailability. The clinical impact of all covariates on roxadustat PK was mild and manageable as the roxadustat dose was titrated based on haemoglobin level and administered starting from a low dose. CONCLUSION: Roxadustat PK in Japanese DD-CKD patients were successfully described by a population PK model. The identified key covariates included coadministration of PBs on the roxadustat bioavailability and age on clearance of roxadustat.

Pilocarpine-Induced Effects on Salivary Secretion as a Pharmacological Biomarker for Cholinergic Parasympathetic Activation.

Pilocarpine-induced salivary secretion could serve as a nontherapeutic target engagement biomarker in a clinical setting to test the activity of an M3 positive allosteric modulator (PAM). The potentiating effect on the reactivity of the M3 receptor to the agonistic effect of pilocarpine would support the mechanism of action of an M3 PAM in a variety of therapeutic areas. The aim of this study was to determine the optimal pilocarpine dose needed for evaluation of this potentiating effect. Therefore, the effects of pilocarpine on salivary secretion rate and its pharmacokinetics were explored at single doses of 2.5, 5, and 10 mg of pilocarpine or placebo. The study also explored the test-retest variability of the pilocarpine-induced effects on salivary secretion. Pilocarpine caused a reproducible, dose-related increase in overall and maximum salivary secretion rate, in line with pilocarpine exposure. Oral doses of pilocarpine from 2.5 to 10 mg were safe and well tolerated, consistent with the published safety profile. These results support the use of pilocarpine in single-dose pharmacological challenge studies. The recommended dose for evaluating M3 PAM activity would be between 2.5 and 5 mg, showing a small increase in salivary secretion rate with room for further increase due to PAM activation.

Effect of the Phosphate Binders Sevelamer Carbonate and Calcium Acetate on the Pharmacokinetics of Roxadustat After Concomitant or Time-separated Administration in Healthy Individuals.

PURPOSE: Roxadustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor, treats anemia in chronic kidney disease. Hyperphosphatemia, a common complication in chronic kidney disease, is treated with phosphate binders (PBs). This study in healthy individuals investigated the effect of 2 PBs, sevelamer carbonate and calcium acetate, on the pharmacokinetic properties of a single oral dose of roxadustat administered concomitantly or with a time lag. METHODS: This 2-part, Phase I study was conducted with an open-label, randomized, 3-way (part 1) or 5-way (part 2) crossover design, with 5-day treatment periods. On day 1 of each period, participants received 200 mg roxadustat administered alone or (1) concomitantly with sevelamer carbonate (2400 mg) or calcium acetate (1900 mg) (part 1) or (2) 1 hour before or 1, 2, or 3 hours after sevelamer carbonate (part 2A) or calcium acetate (part 2B); 5 additional PB doses were administered during 2 days. In both parts, PBs were administered with meals. Primary pharmacokinetic variables were AUC0-∞ and Cmax. FINDINGS: Twenty-four individuals were randomized in part 1; 60 individuals were randomized in part 2 (part 2A, n = 30; part 2B, n = 30). All participants completed the study in part 1; 28 and 27 individuals completed the study in part 2A and part 2B, respectively. Compared with roxadustat alone, concomitant sevelamer carbonate and calcium acetate administration reduced roxadustat's AUC0-∞ by 67% (90% CI, 63.5%-69.3%) and 46% (90% CI, 41.7%-50.9%), respectively, and reduced roxadustat's Cmax by 66% (90% CI, 61.6%-69.4%) and 52% (90% CI, 46.2%-57.2%), respectively. This effect was attenuated when roxadustat and PB administration occurred with a time lag. Roxadustat's AUC0-∞ was reduced by 41% and 22% to 25%, respectively, when roxadustat was administered 1 hour before or 1 to 3 hours after sevelamer carbonate and by 31% and 14% to 18%, respectively, when administered 1 hour before or 1 to 3 hours after calcium acetate. Roxadustat's Cmax was reduced by 26% and 12%, respectively, when roxadustat was administered 1 hour before and 1 hour after sevelamer carbonate; it was reduced by 19% when administered 1 hour before calcium acetate and was not affected when administered 1 hour after. Roxadustat was well tolerated. IMPLICATIONS: Concomitant administration of roxadustat with sevelamer carbonate or calcium acetate reduced exposure to roxadustat in healthy individuals. This effect was attenuated when roxadustat was administered ≥1 hour before or after either PB. Results from this study helped inform dosing and administration guidelines aimed at reducing interactions between roxadustat and these PBs.

Effect of Kidney Function and Dialysis on the Pharmacokinetics and Pharmacodynamics of Roxadustat, an Oral Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitor.

BACKGROUND AND OBJECTIVES: Roxadustat is an orally active hypoxia-inducible factor prolyl hydroxylase inhibitor for anemia in chronic kidney disease. The pharmacokinetics, metabolic profile, and pharmacodynamics of roxadustat were investigated in subjects with different degrees of kidney function. METHODS: This phase 1 open-label study enrolled subjects with normal and severely impaired kidney function, and end-stage renal disease (ESRD) on continuous ambulatory peritoneal dialysis (CAPD) or automated peritoneal dialysis (APD) or hemodialysis/hemodiafiltration (HD/HDF). All subjects received a single 100-mg dose of oral roxadustat. Within a single-sequence, two-treatment period design (P1/P2), subjects with ESRD on HD/HDF received roxadustat 2 h after (P1) and 2 h before (P2) a dialysis session. Area under the plasma concentration-time curve (AUC) from administration to infinity (AUCinf), maximum concentration (Cmax), and terminal elimination half-life (t1/2) were assessed for roxadustat; AUC and Cmax were assessed for erythropoietin. RESULTS: Thirty-four subjects were enrolled and received roxadustat (normal kidney function, n = 12; severely impaired kidney function, n = 9; ESRD on CAPD/APD, n = 1; ESRD on HD/HDF, n = 12). The geometric least-square mean ratio of AUCinf was 223% and 195% in subjects with severely impaired kidney function and ESRD on HD/HDF, respectively, relative to subjects with normal kidney function; Cmax and t1/2 were comparable. The pharmacokinetic profile of roxadustat was not affected by HD/HDF. AUCinf and t1/2 for the metabolites of roxadustat increased in subjects with kidney impairment. The AUC and Cmax of erythropoietin increased in subjects with severely impaired kidney function or ESRD on HD/HDF. Roxadustat was well tolerated. CONCLUSIONS: Kidney function impairment increased the AUC of roxadustat and its metabolites. The Cmax and t1/2 of roxadustat were comparable among groups. Roxadustat and its metabolites were not cleared by HD/HDF. Clinical Trials Registration Number: NCT02965040.

An Open-Label, Single-Dose, Human Mass Balance Study of Amenamevir in Healthy Male Adults.

Amenamevir is an inhibitor of the helicase-primase enzyme complex developed for the treatment of varicella zoster virus. This mass balance study investigated the absorption, metabolism, and excretion of a single dose (200 mg) of 14 C-labeled amenamevir in healthy male volunteers. Blood, urine, and feces samples were collected for up to 8 days after the dose. Safety and tolerability were assessed through voluntary reporting of adverse events, physical examination, and clinical laboratory testing. Amenamevir was rapidly absorbed, with a median time to peak drug concentration of 1.0 to 1.5 hours and a plasma half-life of 8 to 9 hours. Overall, 95.3% of the administered dose was recovered, with the majority of radiolabeled drug excreted in feces (74.6%) followed by urine (20.6%). The major route of elimination was fecal, with around 70% of the dose excreted as metabolites and <0.1% as the unchanged drug. Metabolic profiling revealed that predominantly radiolabeled amenamevir (80%) and its hydroxyl metabolite R5 (up to 7.1%) were present in plasma. Single-dose amenamevir was well tolerated; 3 transient and mild adverse events were reported in 3 subjects. Overall, >95% of a single 200-mg dose of amenamevir was eliminated by 168 hours after the dose, with the major route of elimination being fecal.

Effect of Multiple Doses of Omeprazole on the Pharmacokinetics, Safety, and Tolerability of Roxadustat in Healthy Subjects.

BACKGROUND AND OBJECTIVES: Roxadustat is an orally active hypoxia-inducible factor prolyl hydroxylase inhibitor for the treatment of anemia in chronic kidney disease. This study investigated the effect of multiple daily oral doses of omeprazole on the pharmacokinetics, safety, and tolerability of a single oral dose of roxadustat. METHODS: This phase 1, open-label, two-period, one-sequence, crossover study enrolled healthy subjects. During Period 1, subjects received a single oral dose of 100 mg roxadustat. After a ≥ 7-day washout, subjects started Period 2 and received daily oral doses of 40 mg omeprazole on Days 1-9, and a single oral dose of 100 mg roxadustat on Day 7. Roxadustat pharmacokinetics were assessed on Days 1-4 in Period 1 and on Days 7-10 in Period 2. Primary endpoints were area under the concentration-time profile from the time of dosing extrapolated to infinity (AUCinf) and maximum concentration (Cmax). Safety was assessed by vital signs, laboratory tests, electrocardiograms, and nature, frequency, and severity of treatment-emergent adverse events (TEAEs). RESULTS: Eighteen subjects were enrolled. The geometric least squares mean ratio for both AUCinf and Cmax of roxadustat (with omeprazole/alone) was 104.5%; 90% confidence intervals were within the no-effect boundaries of 80.0 and 125.0%, indicating no significant effect of omeprazole on the pharmacokinetics of roxadustat. No serious TEAEs were reported. CONCLUSION: Multiple daily oral doses of 40 mg omeprazole had no significant effect on the pharmacokinetics of a single oral dose of 100 mg roxadustat. Roxadustat was considered safe and well tolerated when administered alone or in combination with multiple daily oral doses of 40 mg omeprazole in healthy subjects.

Pharmacokinetics and Safety of Amenamevir in Healthy Subjects: Analysis of Four Randomized Phase 1 Studies.

INTRODUCTION: Amenamevir (ASP2151) is a nonnucleoside antiherpesvirus compound available for the treatment of varicella-zoster virus infections. In this article we summarize the findings of four phase 1 studies in healthy participants. METHODS: Four randomized phase 1 studies investigated the safety and pharmacokinetics of single and multiple doses of amenamevir, including the assessment of age group effect (nonelderly vs elderly), food effect, and the relative bioavailability of two formulations. Amenamevir was administered orally at various doses as a single dose (5-2400 mg) or daily (300 or 600 mg/day) for 7 days. RESULTS: Following single and multiple oral doses, amenamevir demonstrated a less than dose proportional increase in the pharmacokinetic parameters area under the plasma drug concentration versus time curve from time zero to infinity (AUCinf) and C max. After single and multiple oral 300-mg doses of amenamevir, no apparent differences in pharmacokinetics were observed between nonelderly and elderly participants. In contrast, with the amenamevir 600-mg dose both the area under the plasma drug concentration versus time curve from time zero to 24 h and C max were slightly increased and renal clearance was decreased in elderly participants. The pharmacokinetics of amenamevir was affected by food, with AUCinf increased by about 90%. In the bioavailability study, AUCinf and C max were slightly lower following tablet versus capsule administration (decreased by 14 and 12%, respectively), with relative bioavailability of 86%. The different amenamevir doses and formulations were safe and well tolerated; no deaths or serious adverse events were reported. CONCLUSION: Amenamevir had less than dose proportional pharmacokinetic characteristics. Age may have an influence on amenamevir pharmacokinetics; however, the effect was considered minimal. The pharmacokinetics of amenamevir were affected by food, with AUCinf almost doubling when amenamevir was administered with food. The concentration versus time profile of the tablet was slightly lower than that of the capsule; the relative bioavailability of the tablet versus the capsule was 86%. Amenamevir was safe and well tolerated in the dose range investigated. FUNDING: Astellas Pharma. TRIAL REGISTRATION: ClinicalTrials.gov identifiers NCT02852876 (15L-CL-002) and NCT02796118 (15L-CL-003).

Pharmacokinetic Evaluation of the Interactions of Amenamevir (ASP2151) with Ketoconazole, Rifampicin, Midazolam, and Warfarin in Healthy Adults.

INTRODUCTION: Amenamevir is a nonnucleoside antiherpes virus compound available for treating herpes zoster infections. Four studies aimed to determine any potential interactions between amenamevir and ketoconazole, rifampicin, midazolam, or warfarin in healthy male participants. METHODS: Two studies were open-label studies that evaluated the effects of multiple doses of ketoconazole (400 mg) and rifampicin (600 mg) on the pharmacokinetics of a single oral dose of amenamevir. The other two studies were randomized, double-blind, parallel-group studies that evaluated the effects of multiple doses of amenamevir on the pharmacokinetics of a single dose of midazolam (7.5 mg) and warfarin (25 mg). A drug interaction was considered to occur if the 90% confidence interval (CI) of the least squares geometric mean ratio (GMR) of amenamevir to the comparator was outside the prespecified interval of 0.80-1.25. RESULTS: Interactions were observed between amenamevir and ketoconazole, rifampicin, and midazolam, but not between amenamevir and warfarin. After a single 400-mg dose of amenamevir, the GMRs of amenamevir plus ketoconazole or rifampicin versus amenamevir alone for C max and the area under the plasma concentration-time curve from time zero to infinity (AUCinf) were 1.30 (90% CI 1.17-1.45) and 2.58 (90% CI 2.32-2.87), respectively, for ketoconazole and 0.42 (90% CI 0.37-0.49) and 0.17 (90% CI 0.15-0.19), respectively, for rifampicin. Following multiple doses of amenamevir (400 mg), the GMRs of midazolam plus amenamevir versus midazolam alone for AUCinf and C max were 0.53 (90% CI 0.47-0.61) and 0.63 (90% CI 0.50-0.80), respectively. After a single dose of warfarin, the (S)-warfarin and (R)-warfarin mean C max increased and mean AUCinf decreased in the presence of amenamevir; however, the 90% CIs of the GMRs for these parameters remained within the predefined limits. CONCLUSION: These findings confirm that amenamevir (as a cytochrome P450 3A4 substrate) can interact with ketoconazole or rifampicin, and (as a cytochrome P450 3A4 inducer) can interact with midazolam; however, no interaction between amenamevir and (S)-warfarin was observed, indicating that amenamevir is not an inducer of cytochrome P450 2C9. FUNDING: Astellas Pharma. TRIAL REGISTRATION: EudraCT2007-002227-33 (study 15L-CL-008), EudraCT2007-002228-14 (study 15L-CL-009), EudraCT2007-002761-13 (study 15L-CL-010), and EudraCT2007-002779-14 (study 15L-CL-018).

Effect of Moderate Hepatic Impairment on the Pharmacokinetics and Pharmacodynamics of Roxadustat, an Oral Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitor.

BACKGROUND AND OBJECTIVE: Roxadustat is a hypoxia-inducible factor prolyl hydroxylase inhibitor in phase III development for the treatment of anaemia associated with chronic kidney disease. This study evaluated the effects of moderate hepatic impairment on roxadustat pharmacokinetics, pharmacodynamics and tolerability. METHODS: This was an open-label study in which eight subjects with moderate hepatic impairment (liver cirrhosis Child-Pugh score 7-9) and eight subjects with normal hepatic function (matched for body mass index, age and sex) received a single oral 100 mg roxadustat dose under fasted conditions. Blood samples were collected until 144 h post-dose in subjects with moderate hepatic impairment and until 96 h post-dose in subjects with normal hepatic function. RESULTS: In subjects with moderate hepatic impairment, area under the concentration-time curve (AUC) from the time of drug administration to infinity (AUC∞) and observed maximum concentration (C max) were 23 % higher [geometric least-squares mean ratio (GMR) 123 %; 90 % CI 86.1-175] and 16 % lower (GMR 83.6 %; 90 % CI 67.5-104), respectively, than in subjects with normal hepatic function. Mean terminal half-life (t ½) appeared to be longer (17.7 vs. 12.8 h) in subjects with moderate hepatic impairment, however intersubject variability on apparent total systemic clearance after single oral dosing (CL/F), apparent volume of distribution at equilibrium after oral administration (V z/F) and t ½ was approximately twofold higher. Erythropoietin (EPO) baseline-corrected AUC from administration to the last measurable EPO concentration (AUCE,last) and maximum effect (E max) were 31 % (GMR 68.95 %; 90 % CI 29.29-162.29) and 48 % (GMR 52.29 %; 90 % CI 28.95-94.46) lower, respectively, than in subjects with normal hepatic function. The single oral roxadustat dose was generally well tolerated. CONCLUSIONS: This study demonstrated the effect of moderate hepatic impairment on the pharmacokinetics and pharmacodynamics of roxadustat relative to subjects with normal hepatic function. These differences are not expected to be of clinical significance.

The Hypoxia-inducible Factor Prolyl-Hydroxylase Inhibitor Roxadustat (FG-4592) and Warfarin in Healthy Volunteers: A Pharmacokinetic and Pharmacodynamic Drug-Drug Interaction Study.

PURPOSE: Roxadustat is a small-molecule hypoxia-inducible factor prolyl-hydroxylase inhibitor in late-stage clinical development for the treatment of anemia in patients with chronic kidney disease (CKD). Warfarin is an oral anticoagulant with a narrow therapeutic window that is often prescribed to treat coexisting cardiovascular diseases in patients with CKD. This clinical trial was designed to evaluate the effect of roxadustat on warfarin pharmacokinetic and pharmacodynamic parameters. METHODS: This open-label, single-sequence crossover study was conducted in healthy volunteers (male or female) aged 18 to 55 years with a body mass index of 18.5 to 30.0 kg/m(2). The study consisted of 2 periods separated by a minimum washout period of 14 days. After an overnight fast, volunteers received a single oral dose of 25 mg (5 × 5 mg tablets) warfarin on Day 1 of Period 1 and Day 7 of Period 2. Volunteers received oral doses of 200 mg (2 × 100 mg tablets) roxadustat on Days 1, 3, 5, 7 (concomitant with warfarin), 9, 11, 13, and 15 of Period 2. Plasma S- and R-warfarin (unbound and total concentrations) and prothrombin time were determined at multiple time points up to 216 hours postdose. Pharmacokinetic and pharmacodynamic parameters were estimated via noncompartmental methods. Tolerability was evaluated by monitoring adverse events, laboratory assays, vital signs, and 12-lead ECGs. FINDINGS: The geometric mean ratios and 90% CIs for Cmax and AUC∞ of total and unbound S- and R-warfarin (with and without roxadustat) were within the standard bioequivalence interval of 80.00% to 125.00%. Roxadustat increased the geometric mean (GM) prothrombin (PT) and international normalized ratio (INR) AUC from time zero to last measurable sample (AUCPT,last and AUCINR,last) by 24.4%. Coadministration of roxadustat and warfarin in healthy volunteers was associated with a favorable tolerability profile, with most treatment-associated adverse events mild in severity. IMPLICATIONS: Based on the lack of clinically significant pharmacokinetic interactions and the limited influence on warfarin pharmacodynamic parameters, no dose adjustment of warfarin should be required when coadministered with roxadustat. ClinicalTrials.gov identifier: NCT02252731.