Effect of Mild and Moderate Hepatic Impairment (Defined by Child-Pugh Classification and National Cancer Institute Organ Dysfunction Working Group Criteria) on Pexidartinib Pharmacokinetics.

Pexidartinib is a novel oral small-molecule tyrosine kinase inhibitor targeting the colony-stimulating factor 1 receptor. Pexidartinib undergoes extensive hepatic metabolism via multiple cytochrome P450 and uridine 5'-diphospho-glucuronosyl transferase enzymes, with ZAAD-1006a as the only major metabolite in human plasma. As pexidartinib is extensively metabolized, hepatic impairment (HI) could lead to increased exposure to pexidartinib. The objective of the two phase 1, open-label studies was to determine the pharmacokinetics of pexidartinib after a single 200-mg dose in subjects with mild and moderate HI, based on Child-Pugh classification (PL3397-A-U123: 8 mild HI and 8 moderate HI vs 16 matched healthy controls) and National Cancer Institute Organ Dysfunction Working Group (NCI-ODWG) criteria (PL3397-A-U129: 8 moderate HI versus 8 matched healthy controls [NCT04223635]). Based on Child-Pugh classification, exposure to pexidartinib (maximum observed concentration [Cmax ], area under the plasma concentration-time curve up to the last measurable concentration [AUClast ], and extrapolated to infinity [AUCinf ]) was similar in subjects with mild and moderate HI and in respective matched healthy controls, whereas ZAAD-1006a exposure (AUC) was approximately 27% to 28% and 41% to 48% higher in mild and moderate HI, respectively. According to NCI-ODWG criteria, total pexidartinib exposure was 42% to 46% higher in subjects with moderate HI, compared with healthy controls, and total ZAAD-1006a exposure was 70% to 79% higher for subjects with moderate HI, compared with matched healthy controls with normal hepatic function. These findings were used to develop appropriate dose recommendations in patients with hepatic impairment.

A Microdose Cocktail to Evaluate Drug Interactions in Patients with Renal Impairment.

Renal impairment (RI) is known to influence the pharmacokinetics of nonrenally eliminated drugs, although the mechanism and clinical impact is poorly understood. We assessed the impact of RI and single dose oral rifampin (RIF) on the pharmacokinetics of CYP3A, OATP1B, P-gp, and BCRP substrates using a microdose cocktail and OATP1B endogenous biomarkers. RI alone had no impact on midazolam (MDZ), maximum plasma concentration (Cmax ), and area under the curve (AUC), but a progressive increase in AUC with RI severity for dabigatran (DABI), and up to ~2-fold higher AUC for pitavastatin (PTV), rosuvastatin (RSV), and atorvastatin (ATV) for all degrees of RI was observed. RIF did not impact MDZ, had a progressively smaller DABI drug-drug interaction (DDI) with increasing RI severity, a similar 3.1-fold to 4.4-fold increase in PTV and RSV AUC in healthy volunteers and patients with RI, and a diminishing DDI with RI severity from 6.1-fold to 4.7-fold for ATV. Endogenous biomarkers of OATP1B (bilirubin, coproporphyrin I/III, and sulfated bile salts) were generally not impacted by RI, and RIF effects on these biomarkers in RI were comparable or larger than those in healthy volunteers. The lack of a trend with RI severity of PTV and several OATP1B biomarkers, suggests that mechanisms beyond RI directly impacting OATP1B activity could also be considered. The DABI, RSV, and ATV data suggest an impact of RI on intestinal P-gp, and potentially BCRP activity. Therefore, DDI data from healthy volunteers may represent a worst-case scenario for clinically derisking P-gp and BCRP substrates in the setting of RI.

Pharmacokinetics and Safety of the Novel Selective Progesterone Receptor Modulator Vilaprisan in Participants With Renal Impairment.

This open label, parallel-group study investigated the pharmacokinetics and safety of a single oral 2-mg dose of the novel selective progesterone receptor modulator vilaprisan in participants with impaired renal function compared with age, weight, sex, and race matched controls with normal renal function. Systemic exposure (area under the plasma concentration-time curve [AUC]) and maximum observed concentrations (Cmax ) were compared among 9 participants with moderate renal impairment and matched controls by ANOVA. An additional 4 participants, each with severe renal impairment or normal renal function, contributed to a linear regression analysis exploring any monotone relationship between individual variables and the estimated glomerular filtration rate. The geometric mean AUC was increased by a factor of 1.35 in renally impaired participants compared to normal controls (not statistically significant: least squares mean, 1.346; 90% confidence interval, 0.918-1.973). Cmax was similar in participants with moderate renal impairment and normal renal function (least squares mean, 1.026; 90% confidence interval, 0.779-1.351). Considering the overall variability, there was no correlation between renal function (estimated glomerular filtration rate) and Cmax or AUC of vilaprisan. Single oral administration of vilaprisan 2 mg was well tolerated by all participants, both men and women and irrespective of renal function. The incidence of treatment-emergent adverse events was similar across all groups. Results from this study do not indicate that a dose adjustment will be necessary for vilaprisan when treating patients up to moderate renal impairment.

Pharmacokinetics, Safety, and Tolerability of Single-Dose Elbasvir in Participants with Hepatic Impairment.

BACKGROUND: The combination of elbasvir and grazoprevir is approved for the treatment of hepatitis C virus genotype 1 or 4 infection. OBJECTIVE: To evaluate the pharmacokinetics and safety of single-dose elbasvir 50 mg in participants with hepatic impairment. METHODS: Participants with mild, moderate, or severe hepatic impairment and age-, sex-, and weight-matched healthy controls were enrolled in a 3-part, open-label, sequential-panel, single-dose pharmacokinetic study. Blood samples were collected to assess pharmacokinetics. Safety and tolerability were assessed throughout the study. RESULTS: Thirty-four participants were enrolled: eight with mild hepatic impairment, 11 with moderate hepatic impairment, seven with severe hepatic impairment, and eight healthy matched controls. Participants with mild, moderate, and severe hepatic impairment demonstrated a numeric, but not statistically significant, decrease in elbasvir exposure compared with controls, with a mean 39, 28, and 12% decrease in area under the concentration-time curve from time 0 extrapolated to infinity, as well as a 42, 31, and 42% decrease in maximum plasma concentration (C max), respectively. The observed median time to C max was similar in participants with hepatic impairment and controls. Single-dose administration of elbasvir was well tolerated. CONCLUSIONS: The pharmacokinetics of elbasvir after a single, oral 50-mg dose were not clinically meaningfully altered in non-HCV-infected participants with mild, moderate, or severe hepatic dysfunction. However, since elbasvir is currently available only as part of a fixed-dose combination with grazoprevir, the fixed-dose combination should not be administered to patients with moderate or severe hepatic impairment, due to the significantly increased plasma grazoprevir exposures in those populations.

The Influence of Hepatic and Renal Impairment on the Pharmacokinetics of a Treatment for Herpes Zoster, Amenamevir (ASP2151): Phase 1, Open-Label, Single-Dose, Parallel-Group Studies.

INTRODUCTION: Amenamevir (ASP2151) is a nonnucleoside human herpesvirus helicase-primase inhibitor that was approved in Japan for the treatment of herpes zoster (shingles) in 2017. This article reports the results of two clinical trials that investigated the effects of renal and hepatic impairment on the pharmacokinetics of amenamevir. METHODS: These studies were phase 1, open-label, single-dose (oral 400 mg), parallel-group studies evaluating the pharmacokinetics, safety, and tolerability of amenamevir in healthy participants and participants with moderate hepatic impairment and mild, moderate, and severe renal impairment. RESULTS: In the hepatic impairment study, the pharmacokinetic profile of amenamevir in participants with moderate hepatic impairment was generally similar to that of participants with normal hepatic function. In the renal impairment study, the area under the amenamevir concentration versus time curve from the time of dosing up to the time of the last sample with extrapolation to infinity of the terminal phase was increased by 78.1% in participants with severe renal impairment. There was a positive relationship between creatinine clearance and oral and renal clearance for amenamevir in the renal impairment study. In both studies, amenamevir was safe and well tolerated. CONCLUSION: The findings of the hepatic impairment study indicate that no dosing adjustment is required in patients with moderate hepatic impairment. In the renal impairment study, systemic amenamevir exposure was increased by renal impairment. However, it is unlikely that renal impairment will have a significant effect on the safety of amenamevir given that in previous pharmacokinetic and safety studies in healthy individuals amenamevir was safe and well tolerated after a single dose (5-2400 mg, fasted condition) and repeated doses for 7 days (300 or 600 mg, fed condition), and the amount of amenamevir exposure in the renal impairment study was covered by those studies. These findings suggest that amenamevir does not require dosage reduction in accordance with the creatinine clearance FUNDING: Astellas Pharma.

Pharmacokinetics of sugammadex in subjects with moderate and severe renal impairment
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AIMS: Sugammadex rapidly reverses moderate and deep rocuronium- or vecuronium-induced neuromuscular blockade at doses of 4 mg/kg and 2 mg/kg, respectively. Sugammadex is renally eliminated. This study evaluated the pharmacokinetics of sugammadex in subjects with renal impairment versus those with normal renal function. METHODS: This open-label, two-part, phase 1 study included adults with moderate (creatinine clearance (CLcr) 30 - < 50 mL/min) and severe (CLcr < 30 mL/min) renal impairment and healthy controls (CLcr ≥ 80 mL/min). A single intravenous (IV) bolus injection of sugammadex 4 mg/kg was administered into a peripheral vein over 10 seconds directly by straight needle in part 1 (n = 24; 8/group), and via an IV catheter followed by a saline flush in part 2 (n = 18; 6/group). Plasma concentrations of sugammadex were collected after drug administration. Due to dosing issues in part 1, pharmacokinetic parameters were determined for part 2 only. Safety was assessed throughout the study. RESULTS: Pharmacokinetic data were obtained from 18 subjects. Mean sugammadex exposure (AUC0-∞) in subjects with moderate and severe renal impairment was 2.42- and 5.42-times, respectively, that of healthy controls. Clearance decreased and apparent terminal half-life was prolonged with increasing renal dysfunction. Similar Cmax values were observed in subjects with renal impairment and healthy controls. There were no serious adverse events. CONCLUSIONS: Sugammadex exposure is increased in subjects with moderate and severe renal insufficiency due to progressively decreased clearance as a function of worsening renal function. Sugammadex 4 mg/kg was well tolerated in subjects with renal impairment, with a safety profile similar to that of healthy subjects. These results indicate that dose adjustment of sugammadex is not required in patients with moderate renal impairment; however, current safety experience is insufficient to support the use of sugammadex in patients with CLcr < 30 mL/min.
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Pharmacokinetic Interactions Between Isavuconazole and the Drug Transporter Substrates Atorvastatin, Digoxin, Metformin, and Methotrexate in Healthy Subjects.

This article summarizes 4 phase 1 trials that explored interactions between the novel, triazole antifungal isavuconazole and substrates of the drug transporters breast cancer resistance protein (BCRP), multidrug and toxin extrusion protein-1 (MATE1), organic anion transporters 1/3 (OAT1/OAT3), organic anion-transporting polypeptide 1B1 (OATP1B1), organic cation transporters 1/2 (OCT1/OCT2), and P-glycoprotein (P-gp). Healthy subjects received single doses of atorvastatin (20 mg; OATP1B1 and P-gp substrate), digoxin (0.5 mg; P-gp substrate), metformin (850 mg; OCT1, OCT2, and MATE1 substrate), or methotrexate (7.5 mg; BCRP, OAT1, and OAT3 substrate) in the presence and absence of clinical doses of isavuconazole (200 mg 3 times a day for 2 days; 200 mg once daily thereafter). Coadministration with isavuconazole increased mean area under the plasma concentration-time curves (90% confidence interval) of atorvastatin, digoxin, and metformin to 137% (129, 145), 125% (117, 134), and 152% (138, 168) and increased mean maximum plasma concentrations to 103% (88, 121), 133% (119, 149), and 123% (109, 140), respectively. Methotrexate parameters were unaffected by isavuconazole. There were no serious adverse events. These findings indicate that isavuconazole is a weak inhibitor of P-gp, as well as OCT1, OCT2, MATE1, or a combination thereof but not of BCRP, OATP1B1, OAT1, or OAT3.

Moderate Hepatic Impairment Does Not Affect Doravirine Pharmacokinetics.

Doravirine is a novel, potent, nonnucleoside reverse-transcriptase inhibitor currently in development for HIV-1 infection treatment. As a substrate for CYP3A-mediated metabolism, doravirine could potentially be affected by liver-function changes. As a portion of the HIV-1-infected population has varying degrees of liver impairment, we investigated the effect of moderate hepatic impairment on the pharmacokinetic profile and tolerability of single-dose doravirine 100 mg in otherwise healthy subjects. A total of 16 subjects aged 44-64 years took part in the open-label, single-dose trial: 8 with moderate hepatic impairment (Child-Pugh score, 7-9; 6 men, 2 women) and 8 healthy individuals (mean age and height matched with the impairment group; 6 men, 2 women). Subjects with hepatic impairment were required to have chronic, stable hepatic impairment with features of cirrhosis of any etiology. Blood sampling revealed that doravirine exposure was similar in both groups. The observed geometric least-squares mean ratio (90% confidence interval; moderately impaired/healthy subjects) was 0.99 (0.72-1.35) for AUC0-∞ , 0.93 (0.74-1.18) for AUC0-24 h , 0.90 (0.66-1.24) for Cmax , and 0.99 (0.74-1.33) for C24 h . Geometric mean apparent terminal t½ was ∼18 hours for both groups, whereas median Tmax was 2 hours (range, 1-6 hours) and 2.5 hours (range, 1-3 hours) for impaired and healthy individuals, respectively. In addition, doravirine was generally well tolerated. The results demonstrate that moderate hepatic impairment does not have a clinically meaningful effect on doravirine pharmacokinetics. Therefore, dose adjustment should not be necessary in patients with both HIV-1 and moderate hepatic impairment.

Influence of renal and hepatic impairment on the pharmacokinetics of anacetrapib.

Two open-label, parallel-group studies evaluated the influence of renal and hepatic insufficiency on the pharmacokinetics of a single-dose anacetrapib 100 mg. Eligible participants included adult men and women with moderate hepatic impairment (assessed by Child-Pugh criteria) or severe renal impairment (CrCl <30 mL/min/1.73 m(2)). In both studies, patients were matched (race, age, sex, BMI) with healthy control subjects. Twenty-four subjects were randomized in each study (12 with either moderate hepatic or severe renal impairment and 12 matched healthy controls). In the hepatic insufficiency study, the geometric mean ratio (GMR; mean value for the group with moderate hepatic insufficiency/mean value for the healthy controls) and 90% CIs for the area under the concentration-time curve from time zero to infinity (AUC(0-∞)) and the maximum concentration of drug in plasma (C(max)) were 1.16 (0.84, 1.60) and 1.02 (0.71, 1.49), respectively. In the renal insufficiency study, the GMRs (mean value for the group with severe renal insufficiency/mean value for the healthy controls) and 90% CIs for AUC(0-∞) and Cmax were 1.14 (0.80, 1.63) and 1.31 (0.93, 1.83), respectively. Anacetrapib was generally well tolerated and there was no clinically meaningful effect of moderate hepatic or severe renal insufficiency on the pharmacokinetics of anacetrapib.

The effect of rifampin on the pharmacokinetics of sirolimus in healthy volunteers.

Sirolimus, metabolized primarily by intestinal and hepatic CYP3A4, is a substrate for P-glycoprotein. CYP3A4 inducers would be expected to decrease sirolimus exposure. This open-label, nonrandomized study investigated effects of CYP3A4 induction, by rifampin, on sirolimus pharmacokinetics. Healthy volunteers received sirolimus 20 mg on day 1. After washout period, multiple 600-mg rifampin doses were administered daily for 14 days. On day 9, one 20-mg sirolimus dose was administered after an overnight fast (≥10 hours). Whole blood samples for sirolimus collected for 144 hours after each dose were analyzed by liquid chromatography/tandem mass spectrometry. Pharmacokinetic parameters, assessed using noncompartmental methods, were compared using analysis of variance. Geometric mean ratios of Cmax and AUCinf were 29% (90% CI: 26, 32%) and 18% (90% CI: 16, 21%), respectively, with rifampin co-administration versus sirolimus alone. Corresponding decreases in Cmax and AUC were 71% and 82%, respectively, which would likely cause trough concentrations to fall below the recommended therapeutic range. Mean CL/F increased approximately fivefold with rifampin versus sirolimus alone. Co-administering sirolimus and potent CYP3A inducers is not recommended. If co-administration is necessary, dose adjustment and concentration monitoring should be conducted.

Evaluation of the single-dose pharmacokinetics of bilastine in subjects with various degrees of renal insufficiency.

BACKGROUND: Bilastine is a novel second-generation H1 antihistamine, which has not shown sedative or cardiotoxic effects in clinical trials and in post-marketing experience so far, developed for the symptomatic treatment of allergic rhinoconjunctivitis and urticaria. It has recently been granted marketing authorization for these therapeutic indications in adults and adolescents at a once-daily oral dose of 20 mg in several European countries. OBJECTIVE: This study was conducted to determine the pharmacokinetics of bilastine at a single oral dose of 20 mg in renally impaired subjects. The need for a dose adjustment in patients with renal insufficiency was assessed by comparing the exposure to bilastine in these subjects with the estimated exposure of a dose corresponding to the safety margin. METHODS: The study was an open-label, single-dose, parallel-group study of the pharmacokinetics and safety of a single dose of bilastine. The study was conducted as an in-patient setting at a clinical pharmacology facility. A total of 24 male or female subjects aged 18-80 years were to be enrolled in four groups of six subjects each. The groups were as follows: (1) healthy [glomerular filtration rate (GFR) >80 mL/min/1.73 m(2)]; (2) mild renal insufficiency (GFR 50-80 mL/min/1.73 m(2)); (3) moderate renal insufficiency (GFR 30-50 mL/min/1.73 m(2)); and (4) severe renal insufficiency (GFR ≤30 mL/min/1.73 m(2)). A single 20 mg bilastine tablet was administered in a fasted state. Blood and urine samples were collected from pre-dose up to 72 h post-dose for bilastine pharmacokinetic analysis. Pharmacokinetic results were summarized using appropriate descriptive statistics. RESULTS: There was a clear trend of increasing area under the plasma concentration-time curve (AUC) and maximum plasma concentration (C(max)) through the groups 1-4. The mean AUC from time zero to infinity (AUC(∞)) ranged from 737.4 to 1708.5 ng·h/mL in healthy subjects and severely impaired subjects, respectively. No significant differences among groups in median time to reach Cmax (tmax) or in the mean terminal disposition rate constants for bilastine were found. Renal and plasma clearance paralleled GFR. In all groups of renally impaired subjects the corresponding 90 % confidence interval of both AUC(∞) and AUC from time zero to time of last measurable plasma concentration (AUC(last)) were not within the 0.8-1.25 interval, indicating that bioequivalence between groups could not be demonstrated. The majority of bilastine was excreted within the first 12 h, and elimination was essentially complete by 72 h. CONCLUSION: An oral dose of bilastine (20 mg) was well-tolerated in renal insufficiency, despite the increase in exposure. The oral plasma clearance to renal clearance ratio [(CL(P)/F)/CL(R)] was approximately equal in the different groups, suggesting that renal excretion was the main elimination route for bilastine, and no alternative elimination routes were used even in severe renal insufficiency. Although exposure to bilastine was higher in renally impaired subjects, it remained well within the safety margins, thus allowing the conclusion that a 20-mg daily dose can be safely administered to subjects with different degrees of renal insufficiency without the need for dose adjustments.

The effect of moderate hepatic impairment on the pharmacokinetics of ipragliflozin, a novel sodium glucose co-transporter 2 (SGLT2) inhibitor.

BACKGROUND: Ipragliflozin (ASP1941), a potent selective sodium glucose co-transporter 2 inhibitor, is in development for the treatment of type 2 diabetes mellitus. Ipragliflozin is primarily eliminated via conjugation by the liver as five pharmacologically inactive metabolites (M1, M2, M3, M4 and M6). This study evaluated the effect of moderate hepatic impairment on the pharmacokinetics of ipragliflozin and its metabolites. METHODS: In an open-label, single-dose, parallel-group study, 16 subjects (eight with moderate hepatic impairment [Child-Pugh score 7-9] and eight healthy, matched controls) received a single oral dose of 100-mg ipragliflozin. Plasma concentrations of ipragliflozin and its metabolites were determined. Adverse events (AEs) and other clinical laboratory parameters were monitored. RESULTS: All subjects completed the study. Least-squares geometric mean ratios (GMRs) (90 % confidence interval [CI]) for maximum plasma concentration (C max) and area under the plasma concentration-time curve from time zero to infinity (AUC∞) of ipragliflozin were 127 % (93-173 %) and 125 % (94-166 %), respectively, in moderate hepatic impairment versus controls. No changes in elimination half-life and protein binding of ipragliflozin were observed in moderate hepatic impairment subjects. Least-squares GMRs for C max and AUC∞ of M2, the major metabolite, were respectively 95 % (68-133 %) and 100 % (77-130 %) in moderate hepatic impairment versus controls. No deaths, other serious AEs or AEs leading to discontinuation occurred. CONCLUSIONS: Moderate hepatic impairment had no clinically relevant effects on the single-dose pharmacokinetics of ipragliflozin and its major metabolite, M2. A single oral dose of ipragliflozin, 100 mg, was well tolerated in both healthy subjects and those with moderate hepatic impairment.

The influence of smoking status on the pharmacokinetics and pharmacodynamics of clopidogrel and prasugrel: the PARADOX study.

OBJECTIVES: The goal of this study was to evaluate the effect of smoking on the pharmacokinetics and pharmacodynamics (PD) of clopidogrel and prasugrel therapy. BACKGROUND: Major randomized trial data demonstrated that nonsmokers experience less or no benefit from clopidogrel treatment compared with smokers (i.e., the "smokers' paradox"). METHODS: PARADOX was a prospective, randomized, double-blind, double-dummy, placebo-controlled, crossover study of objectively assessed nonsmokers (n = 56) and smokers (n = 54) with stable coronary artery disease receiving aspirin therapy. Patients were randomized to receive clopidogrel (75 mg daily) or prasugrel (10 mg daily) for 10 days and crossed over after a 14-day washout. PD was assessed by using VerifyNow P2Y12 and vasodilator-stimulated phosphoprotein phosphorylation assays. Clopidogrel and prasugrel metabolite levels, cytochrome P450 1A2 activity, CYP2C19 genotype, and safety parameters were determined. RESULTS: During clopidogrel therapy, device-reported inhibition of platelet aggregation (IPA) trended lower in nonsmokers than smokers (least squares mean treatment difference ± SE: 7.7 ± 4.1%; p = 0.062). Device-reported IPA was significantly lower in clopidogrel-treated smokers than prasugrel-treated smokers (least squares mean treatment difference: 31.8 ± 3.4%; p < 0.0001). During clopidogrel therapy, calculated IPA was lower and P2Y12 reaction units and vasodilator-stimulated phosphoprotein phosphorylation and platelet reactivity index were higher in nonsmokers than in smokers (p = 0.043, p = 0.005, and p = 0.042, respectively). Greater antiplatelet effects were present after prasugrel treatment regardless of smoking status (p < 0.001 for all comparisons). CONCLUSIONS: PARADOX demonstrated lower clopidogrel active metabolite exposure and PD effects of clopidogrel in nonsmokers relative to smokers. Prasugrel was associated with greater active metabolite exposure and PD effects than clopidogrel regardless of smoking status. The poorer antiplatelet response in clopidogrel-treated nonsmokers may provide an explanation for the smokers' paradox. (The Influence of Smoking Status on Prasugrel and Clopidogrel Treated Subjects Taking Aspirin and Having Stable Coronary Artery Disease; NCT01260584).

Odanacatib, a selective cathepsin K inhibitor to treat osteoporosis: safety, tolerability, pharmacokinetics and pharmacodynamics--results from single oral dose studies in healthy volunteers.

AIMS: To evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of odanacatib (ODN), a cathepsin K inhibitor, in humans. METHODS: Two double-blind, randomized, placebo-controlled, single oral dose studies were performed with ODN (2-600 mg) in 44 healthy volunteers (36 men and eight postmenopausal women). RESULTS: Adverse experiences (AEs) with single doses of ODN were transient and mild to moderate, with the exception of one severe AE of gastroenteritis. Headache was the most frequent AE. After absorption of ODN (initial peak concentrations 4-6 h postdose), plasma concentrations exhibited a monophasic decline, with an apparent terminal half-life of ∼40-80 h. The area under the curve0-24 hours (AUC(0-24 h)), concentration at 24 hours (C(24 h)) and maximum concentration (C(max,overal)) increased in a less than dose-proportional manner from 2 to 600 mg. Administration of ODN with a high-fat meal led to ∼100% increases in AUC(0-24 h), C(max,day1), C(max,overall) and C(24 h) relative to the fasted state, while administration with a low-fat meal led to a ∼30% increase in those parameters. Reduction of biomarkers of bone resorption, the C- and N-telopeptides of cross-links of type I collagen, (CTx and NTx, respectively), was noted at 24 h for doses ≥5 mg and at 168 h postdose for ≥10 mg. In postmenopausal women administered 50 mg ODN, reductions in serum CTx of -66% and urine NTx/creatinine (uNTx/Cr) of -51% relative to placebo were observed at 24 h. At 168 h, reductions in serum CTx (-70%) and uNTx/Cr (-78%) were observed relative to baseline. Pharmacokinetic/pharmacodynamic modeling characterized the ODN concentration/uNTx/Cr relation, with a modeled EC50 value of 43.8 nM and ∼80% maximal reduction. CONCLUSIONS: Odanacatib was well tolerated and has a pharmacokinetic and pharmacodynamic profile suitable for once weekly dosing.

Segmental bioimpedance for measuring amlodipine-induced pedal edema: a placebo-controlled study.

BACKGROUND: The development of antihypertensives requires efficient and accurate tools for identifying pedal edema. Methodologies used to gauge the potential of an agent to induce pedal edema in short-term (<4-week) clinical trials have not been reported in the literature. OBJECTIVE: The purpose of this study was to identify a robust and practical method for measuring drug-induced pedal edema for use in the clinical development of antihypertensives. The efficacy of segmental bioimpedance in the detection of increased pedal edema was compared with that of clinical pitting assessment, ankle circumference, and water displacement volumetry. METHODS: The study population consisted of male and female healthy subjects and patients with stage 1 or 2 hypertension who were otherwise healthy. Participants were randomly assigned to receive amlodipine 10 mg or placebo once daily in this 6-week, double-blind, parallel-group study. Amlodipine was used as a means of inducing ankle edema, and not for the treatment of hypertension. Patients with hypertension were required to undergo a washout of antihypertensive therapies. Edema was evaluated using segmental bioimpedance at 10 kHz, clinical pitting assessment, ankle circumference, and water displacement at weeks 2, 4, and 6. The ANOVA model used included treatment and baseline values as covariates, with treatment pairs compared via t tests derived from the model. RESULTS: A total of 47 individuals were randomized (49% male; 29 [62%] with hypertension; mean [SD] age, 59 [5.9] years; baseline body mass index, 28.6 kg/m(2) [2.8]; blood pressure 146.6 [10.7]/93.5 [6.5] and 139.3 [8.3]/89.5 [4.5] in individuals with and without hypertension, respectively; amlodipine 10 mg, n = 24; placebo, n = 23). At weeks 2, 4, and 6, statistically significant treatment differences in changes from baseline were detected using water displacement (mean [90% CI] treatment differences, +39.0 g [+17.9 to +60.1], +61.9 g [+36.1 to +87.6], and +72.2 g [+42.3 to +102.1], respectively; all, P ≤ 0.001), ankle circumference (+4.74 mm [+2.38 to +7.11; P < 0.001], +2.92 mm [+0.33 to +5.49; P = 0.032], and +5.16 mm [+2.21 to +8.11; P = 0.002]), and bioimpedance (-11.7 Ω [-18.1 to -5.4], -18.3 Ω [-26.2 to -10.4], and -20.9 Ω [-29.7 to -12.0]; all, P≤0.001), but no significant differences were detected using clinical assessment of pitting. CONCLUSION: In this population of healthy subjects and patients with hypertension, segmental bioimpedance was comparable to water displacement and ankle circumference and outperformed clinical assessment of pitting for the detection of ankle edema, supporting the use of segmental bioimpedance as a drug-development tool to objectively quantify amlodipine-induced pedal edema.

Nebivolol withdrawal results in blood pressure returning toward pretreatment levels, but without rebound symptoms: phase IV randomized trial.

Rapid withdrawal of antihypertensive drugs may lead to blood pressure (BP) increase above pretreatment values or symptoms such as palpitations, chest pain, and tremor. This phase IV trial assessed the consequences of abrupt and stepwise withdrawal of nebivolol, a ß(1)-selective blocker, in individuals with stage I-II hypertension. After a 4- to 5-week placebo washout phase and 12-week single-blind nebivolol treatment (10-40 mg/day, titrated based on BP response), participants achieving BP control (systolic BP [SBP]/diastolic BP [DBP] <140/90 mm Hg) or response (SBP decrease ≥10 mm Hg or DBP decrease ≥5 mm Hg) entered a 4-week, randomized, double-blind phase of continued nebivolol treatment (n = 102) or withdrawal to placebo (n = 105). Primary and secondary efficacy measures were changes in mean sitting DBP and SBP, respectively, analyzed using an analysis of covariance model. Safety and tolerability were also assessed. In the withdrawal phase, nebivolol and placebo groups demonstrated mean DBP increases of 1.8 and 7.7 mm Hg, respectively (P < .001), and SBP increases of 3.5 and 7.6 mm Hg (P = .011). Twenty-three (22.5%) nebivolol-treated and 18 (17.1%) placebo-treated participants experienced a treatment-emergent adverse event. No adverse events associated with ß-blocker withdrawal and considered causally related to nebivolol were reported. Nebivolol withdrawal resulted in a mean BP increase near pretreatment levels and was not associated with rebound hypertension.

Pharmacokinetics of oral tonapofylline and its acyl-glucuronide metabolite in patients with mild and moderate hepatic impairment.

The objective of the study was to evaluate the effect of hepatic impairment on the pharmacokinetics of tonapofylline. Patients with mild or moderate hepatic impairment were enrolled in parallel with demographically matched healthy subjects. All study participants received a single 75-mg oral tonapofylline capsule. The pharmacokinetic parameters for both tonapofylline and its active metabolite, acyl-glucuronide (tonapofylline-AG), were affected by hepatic impairment significantly (P < .1) except for time to peak plasma concentration (t(max)), terminal half-life (t(½)), and apparent volume of distribution based on the terminal phase (Vdz/F). In the mild group, peak plasma concentration (C(max)), area under the time-concentration curve from time 0 to 48 hours postdose (AUC(48 h)), and from time 0 to infinity (AU(Cinf)) of tonapofylline modestly increased as compared with the control healthy subjects (GMR 1.62, 1.57, and 1.53, respectively). The extent of increase of these parameters for tonapofylline-AG was more profound than tonapofylline with geometric mean ratio (GMR) ranging from 2.02 to 2.08. Moderate hepatic impairment was also associated with modest increases of C(max), AUC(48 h), and AUC(inf) of tonapofylline (GMR 1.41, 1.98, and 2.08, respectively). Similar to the mild group, the increase of these parameters were higher for tonapofylline-AG with GMR ranging from 2.80 to 3.86. Single oral 75-mg tonapofylline was safe and well tolerated in patients with mild or moderate hepatic impairment.

Sitagliptin, a dipeptidyl peptidase-4 inhibitor, does not affect the pharmacokinetics of ethinyl estradiol or norethindrone in healthy female subjects.

Sitagliptin is a dipeptidyl peptidase-IV (DPP-4) inhibitor used for the treatment of patients with type 2 diabetes mellitus. This randomized, placebo-controlled, 2-period, crossover study evaluated the effect of sitagliptin on the pharmacokinetics of 17 α-ethinyl estradiol (EE(2)) and norethindrone (NET) in healthy female subjects who were receiving oral contraceptives for >3 months prior to enrollment. A total of 18 subjects with normal menstrual cycles received the oral contraceptive pill ORTHO-NOVUM(®) 7/7/7 on days 1 to 28 for 2 successive cycles, and on days 1 to 21 were randomly assigned to receive sitagliptin 200 mg/day (2 × 100 mg tablets) or placebo using a computer-generated allocation schedule. Blood samples for determination of plasma EE(2) and NET concentrations were collected predose and 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, 18, and 24 hours postdose on day 20 or 21 of each treatment period. The GMRs (90% confidence interval [CI]) for the AUC(0-24 hr) of EE(2) and NET were 0.99 (0.93, 1.06) and 1.03 (0.97, 1.09), respectively, and for C(max) were 0.97 (0.86, 1.10) and 0.98 (0.89, 1.07), respectively. The coadministration of sitagliptin 200 mg/day with an oral contraceptive for 21 days did not lead to clinically meaningful alterations in the pharmacokinetics of EE(2) and NET.

Aclidinium bromide, a long-acting antimuscarinic, does not affect QT interval in healthy subjects.

In this phase I trial, the effect of aclidinium, a novel, inhaled long-acting muscarinic antagonist, on QT interval was evaluated, and its cardiovascular safety was assessed in 272 healthy subjects. Aclidinium 200 µg, aclidinium 800 µg, matching placebo, or open-label moxifloxacin 400 mg was administered daily for 3 days. The primary outcome was mean change in individual heart rate-corrected QT interval (QTcI). Secondary measures included Bazett-corrected QT interval (QTcB), Fridericia-corrected (QTcF) intervals, 12-lead electrocardiogram (ECG) readings, and 24-hour 12-lead Holter ECG parameters. Adverse events, vital signs, and laboratory and pharmacokinetic parameters were also assessed. Maximum mean QTcI change from time-matched baseline on day 3 was -1.0 milliseconds at 2 hours for aclidinium 200 µg, -1.8 milliseconds at 5 minutes for 800 µg, +11.0 milliseconds at 4 hours for moxifloxacin, and -1.2 milliseconds at 23.5 hours for placebo. Aclidinium had no significant effects on secondary ECG measures. Aclidinium plasma concentrations were generally below the lower limit of quantitation (0.05 ng/mL) after 200 µg and were detected only up to 1 hour after the 800-µg dose in the majority of cases. It is concluded that aclidinium bromide, at doses up to 800 µg, has a favorable cardiovascular safety profile with no effect on QT interval.

Pharmacokinetics of laropiprant, a selective prostaglandin D2 receptor 1 antagonist, in patients with moderate hepatic impairment.

This open-label study evaluated the influence of hepatic insufficiency on the pharmacokinetics of laropiprant (LRPT), a prostaglandin D(2) receptor-1 antagonist, to guide clinicians in the event of inadvertent dosing in patients with hepatic insufficiency. A single oral 40-mg dose of LRPT was administered to 8 patients with moderate hepatic insufficiency and 8 healthy control participants matched for important baseline characteristics. Blood samples were collected predose and up to 96 hours postdose to assess LRPT pharmacokinetics. No clinically significant effect of hepatic insufficiency would be declared if the 90% confidence interval (CI) for the estimated geometric mean ratio (GMR; hepatic insufficiency patients/healthy participants) of AUC(0-∞) was contained within the prespecified bounds of (0.50-3.00). Estimated GMRs of AUC(0-∞) and C(max) (90% CIs) were 2.78 (1.71, 4.50) and 2.17 (1.33, 3.53), respectively. The median time to C(max) and apparent terminal t(1/2) of LRPT were comparable between the 2 populations (P > .100). Single-dose LPRT 40 mg was generally well tolerated in all patients. The plasma pharmacokinetics of a single 40-mg oral dose of LRPT is not similar between patients with moderate hepatic insufficiency and matched healthy participants. The GMR (90% CI) of AUC(0-∞) for patients with moderate hepatic insufficiency versus matched controls was 2.78 (1.71, 4.50).