Azra Hussaini

Tafenoquine at therapeutic concentrations does not prolong fridericia-corrected QT interval in healthy subjects

Tafenoquine is being developed for relapse prevention in Plasmodium vivax malaria. This Phase I, single‐blind, randomized, placebo‐ and active‐controlled parallel group study investigated whether tafenoquine at supratherapeutic and therapeutic concentrations prolonged cardiac repolarization in healthy volunteers. Subjects aged 18–65 years were randomized to one of five treatment groups (n = 52 per group) to receive placebo, tafenoquine 300, 600, or 1200 mg, or moxifloxacin 400 mg (positive control). Lack of effect was demonstrated if the upper 90% CI of the change from baseline in QTcF following supratherapeutic tafenoquine 1200 mg versus placebo (ΔΔQTcF) was <10 milliseconds for all pre‐defined time points. The maximum ΔΔQTcF with tafenoquine 1200 mg (n = 50) was 6.39 milliseconds (90% CI 2.85, 9.94) at 72 hours post‐final dose; that is, lack of effect for prolongation of cardiac depolarization was demonstrated. Tafenoquine 300 mg (n = 48) or 600 mg (n = 52) had no effect on ΔΔQTcF. Pharmacokinetic/pharmacodynamic modeling of the tafenoquine–QTcF concentration–effect relationship demonstrated a shallow slope (0.5 ms/μg mL–1) over a wide concentration range. For moxifloxacin (n = 51), maximum ΔΔQTcF was 8.52 milliseconds (90% CI 5.00, 12.04), demonstrating assay sensitivity. In this thorough QT/QTc study, tafenoquine did not have a clinically meaningful effect on cardiac repolarization.

Identification of airway mucosal type 2 inflammation by using clinical biomarkers in asthmatic patients.

Background The Airways Disease Endotyping for Personalized Therapeutics (ADEPT) study profiled patients with mild, moderate, and severe asthma and nonatopic healthy control subjects. Objective We explored this data set to define type 2 inflammation based on airway mucosal IL‐13–driven gene expression and how this related to clinically accessible biomarkers. Methods IL‐13–driven gene expression was evaluated in several human cell lines. We then defined type 2 status in 25 healthy subjects, 28 patients with mild asthma, 29 patients with moderate asthma, and 26 patients with severe asthma based on airway mucosal expression of (1) CCL26 (the most differentially expressed gene), (2) periostin, or (3) a multigene IL‐13 in vitro signature (IVS). Clinically accessible biomarkers included fraction of exhaled nitric oxide (Feno) values, blood eosinophil (bEOS) counts, serum CCL26 expression, and serum CCL17 expression. Results Expression of airway mucosal CCL26, periostin, and IL‐13–IVS all facilitated segregation of subjects into type 2–high and type 2–low asthmatic groups, but in the ADEPT study population CCL26 expression was optimal. All subjects with high airway mucosal CCL26 expression and moderate‐to‐severe asthma had Feno values (≥35 ppb) and/or high bEOS counts (≥300 cells/mm3) compared with a minority (36%) of subjects with low airway mucosal CCL26 expression. A combination of Feno values, bEOS counts, and serum CCL17 and CCL26 expression had 100% positive predictive value and 87% negative predictive value for airway mucosal CCL26–high status. Clinical variables did not differ between subjects with type 2–high and type 2–low status. Eosinophilic inflammation was associated with but not limited to airway mucosal type 2 gene expression. Conclusion A panel of clinical biomarkers accurately classified type 2 status based on airway mucosal CCL26, periostin, or IL‐13–IVS gene expression. Use of Feno values, bEOS counts, and serum marker levels (eg, CCL26 and CCL17) in combination might allow patient selection for novel type 2 therapeutics.

Pharmacokinetic Interactions between Tafenoquine and Dihydroartemisinin-Piperaquine or Artemether-Lumefantrine in Healthy Adult Subjects

ABSTRACT Tafenoquine is in development as a single-dose treatment for relapse prevention in individuals with Plasmodium vivax malaria. Tafenoquine must be coadministered with a blood schizonticide, either chloroquine or artemisinin-based combination therapy (ACT). This open-label, randomized, parallel-group study evaluated potential drug interactions between tafenoquine and two ACTs: dihydroartemisinin-piperaquine and artemether-lumefantrine. Healthy volunteers of either sex aged 18 to 65 years without glucose-6-phosphate dehydrogenase deficiency were randomized into five cohorts (n = 24 per cohort) to receive tafenoquine on day 1 (300 mg) plus once-daily dihydroartemisinin-piperaquine on days 1, 2, and 3 (120 mg/960 mg for 36 to <75 kg of body weight and 160 mg/1,280 mg for ≥75 to 100 kg of body weight), or plus artemether-lumefantrine (80 mg/480 mg) in two doses 8 h apart on day 1 and then twice daily on days 2 and 3, or each drug alone. The pharmacokinetic parameters of tafenoquine, piperaquine, lumefantrine, artemether, and dihydroartemisinin were determined by using noncompartmental methods. Point estimates and 90% confidence intervals were calculated for area under the concentration-time curve (AUC) and maximum observed plasma concentration (Cmax) comparisons of tafenoquine plus ACT versus tafenoquine or ACT. All subjects receiving dihydroartemisinin-piperaquine experienced QTc prolongation (a known risk with this drug), but tafenoquine coadministration had no clinically relevant additional effect. Tafenoquine coadministration had no clinically relevant effects on dihydroartemisinin, piperaquine, artemether, or lumefantrine pharmacokinetics. Dihydroartemisinin-piperaquine coadministration increased the tafenoquine Cmax by 38% (90% confidence interval, 25 to 52%), the AUC from time zero to infinity (AUC0–∞) by 12% (1 to 26%), and the half-life (t1/2) by 29% (19 to 40%), with no effect on the AUC from time zero to the time of the last nonzero concentration (AUC0–last). Artemether-lumefantrine coadministration had no effect on tafenoquine pharmacokinetics. Tafenoquine can be coadministered with dihydroartemisinin-piperaquine or artemether-lumefantrine without dose adjustment for any of these compounds. (This study has been registered at ClinicalTrials.gov under registration no. NCT02184637.)

Pharmacokinetics and Tolerability of Letermovir Coadministered With Azole Antifungals (Posaconazole or Voriconazole) in Healthy Subjects

Letermovir is a human cytomegalovirus terminase inhibitor for cytomegalovirus infection prophylaxis in hematopoietic stem cell transplant recipients. Posaconazole (POS), a substrate of glucuronosyltransferase and P‐glycoprotein, and voriconazole (VRC), a substrate of CYP2C9/19, are commonly administered to transplant recipients. Because coadministration of these azoles with letermovir is expected, the effect of letermovir on exposure to these antifungals was investigated. Two trials were conducted in healthy female subjects 18 to 55 years of age. In trial 1, single‐dose POS 300 mg was administered alone, followed by a 7‐day washout; then letermovir 480 mg once daily was given for 14 days with POS 300 mg coadministered on day 14. In trial 2, on day 1 VRC 400 mg was given every 12 hours; on days 2 and 3, VRC 200 mg was given every 12 hours, and on day 4 VRC 200 mg. On days 5 to 8, letermovir 480 mg was given once daily. Days 9 to 12 repeated days 1 to 4 coadministered with letermovir 480 mg once daily. In both trials, blood samples were collected for the assessment of the pharmacokinetic profiles of the antifungals, and safety was assessed. The geometric mean ratios (90%CIs) for POS+letermovir/POS area under the curve and peak concentration were 0.98 (0.83, 1.17) and 1.11 (0.95, 1.29), respectively. Voriconazole+letermovir/VRC area under the curve and peak concentration geometric mean ratios were 0.56 (0.51, 0.62) and 0.61 (0.53, 0.71), respectively. All treatments were generally well tolerated. Letermovir did not affect POS pharmacokinetics to a clinically meaningful extent but decreased VRC exposure. These results suggest that letermovir may be a perpetrator of CYP2C9/19‐mediated drug‐drug interactions.

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 albiglutides 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.

Single-dose, four-way crossover, open-label, relative bioavailability (BA) studies of a novel formulation of abiraterone acetate (AA) versus the reference formulation under fasted conditions in healthy male subjects.

e605Background: AA is approved for treatment of metastatic castration-resistant prostate cancer. The originator AA (OAA) formulation is poorly absorbed and exhibits large pharmacokinetic variability in abiraterone exposure in healthy subjects. AA fine particle (AAFP) is a proprietary formulation (utilizing SoluMatrix Fine-Particle Technology) that was designed to provide improved BA versus the OAA formulation. Methods: In Study 1, 20 subjects were randomized in a crossover design to single doses of AAFP 100, 200, or 400 mg or OAA 1000 mg. To further expand the AAFP dose range, 36 subjects were randomized in a crossover design to AAFP 125, 500, or 625 mg or OAA 1000 mg in Study 2. Both studies included a 7-day washout period prior to crossover. Results: AAFP 500 mg BA relative to OAA 1000 mg measured by the ratio of test-to-reference geometric means was AUC0-t 93.4% (90% CI: 85.3–102.4%), AUC0-∞ 91.0% (90% CI: 83.3–99.4%), and Cmax99.8% (90% CI: 86.3–115.5%). Dose proportionality was seen across all AAFP d...