Comparison of Two Manufacturing Processes of Daprodustat for Bioequivalence and Dissolution in Healthy Volunteers: A Randomized Crossover Study.

Daprodustat, an orally bioavailable hypoxia-inducible factor-prolyl hydroxylase enzyme inhibitor, has recently completed phase 3 clinical development for treating anemia of chronic kidney disease. Part A of this 2-part, randomized, double-blind, single-dose, cross-over study (NCT04640311) compared pharmacokinetic properties of a single oral dose of daprodustat 4 mg tablets manufactured via twin-screw wet granulation (process 1) to 2 sets of 4 mg tablets manufactured via high-shear wet granulation (process 2), to assess the impact of different dissolution profiles on pharmacokinetics. Part B assessed the bioequivalence of daprodustat tablets manufactured via process 1 with tablets manufactured via process 2 at 5 different dose strengths (1, 2, 4, 6, and 8 mg). In part A, mean plasma concentrations of daprodustat were comparable over a 24-hour period despite differences in manufacturing processes and dissolution profiles. In part B, the 90% confidence intervals of the ratios of the least squared means for area under the concentration-time curve and maximum observed plasma concentration fell within the 0.8-1.25 bioequivalence range for all doses, except for maximum observed plasma concentration at 8 mg. A prespecified sensitivity analysis jointly assessing all doses showed bioequivalence for all doses tested. No new safety concerns for daprodustat were identified.

Pharmacokinetics of Daprodustat and Metabolites in Individuals with Normal and Impaired Hepatic Function.

Daprodustat is a hypoxia-inducible factor-prolyl hydroxylase inhibitor in development for treatment of anemia of chronic kidney disease. We evaluated the role of hepatic impairment on daprodustat pharmacokinetics, pharmacodynamics, and tolerability. Participants with mild (Child-Pugh Class A, score 5-6) and moderate (Child-Pugh Class B, score 7-9) hepatic impairment and matched healthy controls were administered single 6-mg doses of daprodustat. Exposure parameters were determined for daprodustat and its six metabolites. Comparisons resulted in 1.5- and 2.0-fold higher daprodustat Cmax and area under the curve (AUC) exposures in participants with mild and moderate hepatic impairment, respectively, versus controls; Cmax in mild hepatic impairment was comparable to controls. Similarly, aligned with parent drug, unbound daprodustat Cmax and AUC exposures increased 1.6- to 2.3-fold in hepatic-impaired participants versus controls, and metabolite exposures were 1.2- to 2.0-fold higher in participants with hepatic impairment. Erythropoeitin (EPO) baseline-corrected AUC exposures were between 0.3-fold lower and 2.2-fold higher in matched controls versus hepatic-impaired participants. No serious or study drug-related adverse events were reported. Daprodustat exposure was increased in participants with moderate and mild hepatic impairment compared with matched controls; however, no meaningful differences in EPO were observed and no new safety concerns were identified (ClinicalTrials.gov: NCT03223337).

Efficacy and safety of an albiglutide liquid formulation compared with the lyophilized formulation: A 26-week randomized, double-blind, repeat-dose study in patients with type 2 diabetes mellitus.

AIMS: Compare the efficacy and safety of albiglutide from a ready-to-use, single-dose, auto-injector system with the lyophilized product in patients with type 2 diabetes mellitus (T2DM). METHODS: In this phase 3 study, 308 patients between 18 and 80 years with T2DM and experiencing inadequate glycemic control on their current regimen of diet/exercise alone or in combination with metformin were randomized 1:1 to weekly injections for 26 weeks with an active albiglutide auto-injector and placebo lyophilized dual-chamber cartridge (DCC) pen injector (n = 154) or active albiglutide lyophilized DCC pen injector and placebo liquid auto-injector (n = 154). Participants received liquid or lyophilized albiglutide 30 mg for 4 weeks, and then 50 mg for the remaining 22 weeks. Change in HbA1c and fasting plasma glucose (FPG), pharmacokinetics, and safety were assessed. RESULTS: In the albiglutide liquid and lyophilized drug product groups, 55.6% (85/153) and 45.5% of patients (70/154) had a baseline HbA1c ≥ 8.0%, respectively. The model-adjusted least squares (LS) mean change in HbA1c from baseline at week 26 was -1.1% (95% CI: -1.3, -1.0) and -1.2% (95% CI: -1.3, -1.0; noninferiority P = 0.0002) in the albiglutide liquid and lyophilized product groups, respectively. Similarly, the model-adjusted LS mean change in FPG from baseline at week 26 in the albiglutide liquid and lyophilized product groups was -2.2 (95% CI: -2.6, -1.8) mmol/L and -1.9 (95% CI: -2.3, -1.5) mmol/L, respectively. No new safety concerns were identified. CONCLUSION: Change from baseline in HbA1c for albiglutide liquid was noninferior to lyophilized drug product in patients with T2DM.

A Randomized, Double-Blind, Single-Dose, Crossover Study to Demonstrate the Bioequivalence of 2 Formulations of Albiglutide in Healthy Adult Participants.

Albiglutide, developed for treatment of type 2 diabetes mellitus, is provided in a dual-chamber cartridge (DCC) single-dose pen-injector containing lyophilized drug that must be reconstituted with diluent prior to use. A liquid formulation of albiglutide has been developed that does not require mixing. In this 2-period, randomized, crossover, double-blind, phase I study (NCT02660736) in 59 healthy volunteers, pharmacokinetic parameters were determined and the bioequivalence of the 2 formulations was assessed. Participants received injections from each type of pen-injector, one containing albiglutide 50 mg and one containing placebo, followed by an 8-week washout period between regimens: albiglutide 50-mg liquid formulation from an auto-injector and lyophilized placebo from a DCC pen-injector (Regimen A), or placebo liquid from an auto-injector and lyophilized albiglutide 50 mg from a DCC pen-injector (Regimen B). Geometric mean total exposures (area under the drug concentration-time curve [AUC](0-t) [1345.4 vs 1426.9 (µg · h/mL)], AUC(0-∞) [1376.2 vs 1454.6 (µg · h/mL)], and maximum concentration of drug in blood plasma [4968.5 vs 5314.7 ng/mL]) were comparable between Regimens A and B. Ratios of geometric least square means (90% confidence interval) were 95.3% (89.49-101.52) for AUC(0-∞) , 95.1% (89.12-101.49) for AUC(0-t) , and 93.2% (86.76-100.17) for maximum concentration of drug in blood plasma, falling within the 90% confidence interval of 0.80 to 1.25 for bioequivalence. No new safety concerns were observed.

Effect of Albiglutide on Cholecystokinin-Induced Gallbladder Emptying in Healthy Individuals: A Randomized Crossover Study.

The glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) exenatide and lixisenatide reduce cholecystokinin (CCK)-induced gallbladder emptying in healthy subjects. It is unknown if all GLP-1 RAs share this effect; therefore, the effect of the GLP-1 RA albiglutide on gallbladder function was assessed. In this randomized, double-blind, 2-way crossover study, a single dose of subcutaneous albiglutide 50 mg or placebo was administered to 17 healthy subjects, and CCK-induced gallbladder contractility was measured by ultrasonography. CCK (0.003 µg/kg) was infused intravenously over 50 minutes on study day 4 (3 days after dosing, to coincide with albiglutide's expected time to maximum concentration). Gallbladder volume, ejection fraction, and the main pancreatic and common bile-duct diameters were measured before, during, and following CCK infusion. Gallbladder volume was significantly greater in the albiglutide vs placebo groups before, during, and after CCK infusion, and the mean difference from placebo increased numerically during CCK infusion. The area under the volume-effect curve was significantly greater with albiglutide (P = .029). Starting at the 30-minute CCK infusion time point, the gallbladder ejection fraction was significantly lower with albiglutide than placebo. Changes in pancreatic duct diameter and common bile-duct diameter were not significantly different between albiglutide and placebo. Similar incidences of adverse events were observed between the albiglutide and placebo treatment periods. No new albiglutide safety signals were detected, and no serious adverse events were reported. In conclusion, similar to other GLP-1 RAs, albiglutide decreased CCK-induced gallbladder emptying compared with placebo in healthy individuals. Clinical implications of the gallbladder effects are unclear at this time.

The pharmacokinetics and safety of darapladib in subjects with severe renal impairment.

AIM: Darapladib is a potent and reversible orally active inhibitor of lipoprotein-associated phospholipase A2 (Lp-PLA2 ). The aim of the study was to assess the effects of severe renal impairment on the pharmacokinetics and safety/tolerability of darapladib compared with normal renal function. METHODS: This was an open label, parallel group study of darapladib following 10 day once daily 160 mg oral dosing in subjects with normal (n = 8) and severe renal impairment (estimated glomerular filtration rate <30 ml min(-1) 1.73 m(-2) , n = 8). Plasma concentrations of total and unbound darapladib as well as total darapladib metabolites were determined in samples obtained over 24 h on day 10. RESULTS: Plasma concentrations of total and unbound darapladib as well as all three metabolites were higher in subjects with severe renal impairment. Area under the plasma concentration vs. time curve between time zero and 24 h (AUC(0,24 h) and maximum plasma concentration (Cmax ) of total darapladib in severely renally impaired subjects were 52% and 59% higher than those in the matched healthy subjects, respectively. Similar results were found with the darapladib metabolites. Darapladib was highly plasma protein bound with 0.047% and 0.034% unbound circulating in plasma in severely renally impaired and healthy subjects, respectively. Unbound plasma darapladib exposures were more than two-fold higher in severely renally impaired subjects than in healthy controls. Adverse events (AE) were reported in 38% of healthy subjects and 75% of severely renally impaired subjects, most of which were mild or moderate in intensity. CONCLUSIONS: The results of this study showed that darapladib exposure was increased in subjects with severe renal impairment compared with healthy controls. However, darapladib was generally well tolerated in both groups.

Utility of concentration-effect modeling and simulation in a thorough QT study of losmapimod.

A thorough QT study was conducted in healthy volunteers with losmapimod. Four treatment regimens were included: a therapeutic dose (7.5 mg BID for 5 days), a supratherapeutic dose (20 mg QD for 5 days), a positive control (400 mg moxifloxacin single dose on Day 5), and placebo for 5 days. Baseline and on treatment ECGs were measured on Day 1 (3 timepoints predose) and Day 5, respectively. The primary statistical analysis failed to demonstrate a lack of effect of losmapimod on the QT interval leading to a positive finding. However, simulations using the concentration-effect model established for QTcF vs. losmapimod concentration at concentrations 4× the maximum concentration of the therapeutic dose did not exceed the regulatory thresholds of concern of 5 milliseconds for the mean (4.57 milliseconds) and 10 milliseconds for the upper bound of the 90%CI (90%CI 2.88, 6.10). Modeling demonstrated that the discrepant results may have been due to a baseline shift after repeat dosing and baseline differences between the treatments. Considering the results of the concentration-effect modeling, previous losmapimod data, and the high false-positive rate associated with the ICH E14 statistical analysis, the statistical analysis was likely a false-positive.

An effect of moderate hepatic impairment on the pharmacokinetics and safety of darapladib.

AIM/METHODS: This was a phase 1, open label, non-randomized study designed to assess the pharmacokinetics and safety/tolerability of 10 consecutive once daily 40 mg oral doses of darapladib in subjects with moderate hepatic impairment (n = 12) compared with matched healthy volunteers (n = 12). RESULTS: For total darapladib, a small increase in total and peak exposure was observed in the subjects with moderate hepatic impairment compared with the subjects with normal hepatic function. The area under the plasma concentration-time curve during a dosing interval of duration τ (AUC(0,τ), geometric mean 223 ng ml(-1) h [90% CI 158, 316 ng ml(-1 ) h], in moderate hepatic impaired subjects, vs. geometric mean 186 ng ml(-1 ) h [90% CI 159, 217 ng ml(-1 ) h], in healthy subjects) and maximum concentration (Cmax ) were 20% and 7% higher, respectively, in the subjects with moderate hepatic impairment than in the healthy control subjects and there was no change in time to maximum concentration (tmax ). Protein binding was performed to measure the amount of unbound drug vs. bound. Steady-state was achieved by day 10 for darapladib and its metabolites (M4, M3 and M10). Darapladib was generally well tolerated, with adverse events (AEs) reported by seven subjects in the hepatic impairment group and three subjects in the healthy matched group (five and one of which were drug-related AEs, respectively). The most common AEs were gastrointestinal. These AEs were mostly mild to moderate and there were no deaths, serious AEs or withdrawals due to AEs. CONCLUSIONS: The results of this phase 1 study show that darapladib (40 mg) is well tolerated and its pharmacokinetics remain relatively unchanged in patients with moderate hepatic impairment.

Platelet aggregation unchanged by lipoprotein-associated phospholipase A2 inhibition: results from an in vitro study and two randomized phase I trials.

BACKGROUND: We explored the theorized upregulation of platelet-activating factor (PAF)- mediated biologic responses following lipoprotein-associated phospholipase A2 (Lp-PLA2) inhibition using human platelet aggregation studies in an in vitro experiment and in 2 clinical trials. METHODS AND RESULTS: Full platelet aggregation concentration response curves were generated in vitro to several platelet agonists in human plasma samples pretreated with rilapladib (selective Lp-PLA2 inhibitor) or vehicle. This was followed by a randomized, double-blind crossover study in healthy adult men (n = 26) employing a single-agonist dose assay of platelet aggregation, after treatment of subjects with 250 mg oral rilapladib or placebo once daily for 14 days. This study was followed by a second randomized, double-blind parallel-group trial in healthy adult men (n = 58) also treated with 250 mg oral rilapladib or placebo once daily for 14 days using a full range of 10 collagen concentrations (0-10 µg/ml) for characterizing EC50 values for platelet aggregation for each subject. Both clinical studies were conducted at the GlaxoSmithKline Medicines Research Unit in the Prince of Wales Hospital, Sydney, Australia. EC50 values derived from multiple agonist concentrations were compared and no pro-aggregant signals were observed during exposure to rilapladib in any of these platelet studies, despite Lp-PLA2 inhibition exceeding 90%. An increase in collagen-mediated aggregation was observed 3 weeks post drug termination in the crossover study (15.4% vs baseline; 95% confidence interval [CI], 3.9-27.0), which was not observed during the treatment phase and was not observed in the parallel-group study employing a more robust EC50 examination. CONCLUSIONS: Lp-PLA2 inhibition does not enhance platelet aggregation. TRIAL REGISTRATION: 1) Study 1: ClinicalTrials.gov NCT01745458 2) Study 2: ClinicalTrials.gov NCT00387257.

Evaluation of vardenafil and sildenafil on cardiac repolarization.

This novel study evaluated the effects of vardenafil and sildenafil on QT and corrected QT (QTc) duration using a model that minimizes experimental error to obtain the most accurate assessment of observed QTc effects. A placebo-controlled and positive-controlled, period-balanced, double-blinded, 6-way crossover study evaluated therapeutic and supratherapeutic oral doses of vardenafil (10 and 80 mg, respectively) and sildenafil (50 and 400 mg, respectively), therapeutic doses of moxifloxacin (400 mg), and a placebo in 58 healthy men (mean age 53 years), with dosing every 3 days. Six replicate, 12-lead, digital electrocardiograms (ECGs) were recorded at 3 time points before and 5 time points after dosing to cover the time course of maximum exposure to study drugs and their metabolites. An independent laboratory blindly analyzed approximately 17,000 ECGs. For the placebo, mean change in QTcF (Fridericia) duration 1 hour after dose (approximate Tmax of vardenafil and sildenafil) was 0 ms (+/-0.7 SD). QT/QTc variability was small across regimens, indicating statistically powerful results. Moxifloxacin demonstrated an expected 8-ms mean change and was the only drug to prolong absolute QT. Placebo-corrected mean changes in QTcF duration (90% confidence interval) at 1 hour after dose were 8 ms (range 6 to 9) for vardenafil 10 mg and 6 ms (range 5 to 8) for sildenafil 50 mg. QTci (linear and nonlinear per patient) yielded similar trends: 4 ms (range 3 to 6) for vardenafil 10 mg and 4 ms (range 2 to 5) for sildenafil 50 mg. Dose response demonstrated very shallow QTc relations for study drugs. Therapeutic and supratherapeutic doses produced only small increases in the QTcF interval, which were considered to be clinically irrelevant. This well-controlled, statistically powerful study in middle-aged men demonstrated that vardenafil and sildenafil produced no increase of absolute QT and only similar, small increases of the QTc interval, with a shallow dose-response curve. The study design and conduct may serve as a guide for future QT assessment of new drugs.