A Four-Way, Cross-Over Design, Randomized, Double-Blinded, Placebo-&Active-Controlled Study for the Evaluation of the Effect of a Supratherapeutic Dose of Sofpironium Bromide Gel, 15% Applied Topically on the QT/QTc Intervals in Adult Healthy Volunteers

not available.

114 An Assessment of QTc Effects With SPN-812 (Extended-Release Viloxazine) in Healthy Adults

Study Objective:SPN-812 (extended-release viloxazine) is a structurally distinct, bicyclic, Serotonin Norepinephrine Modulating Agent (SNMA) under investigation as a treatment for attention-deficit/hyperactivity disorder (ADHD). One concern for any new drug is prolongation of the QT interval, which is associated with increased risk for potentially very harmful ventricular cardiac arrhythmias such as torsades de pointes (TdP). The objective of this study was to assess the effects of SPN-812 at a supratherapeutic dose (1800 mg once daily [QD]) on cardiac repolarization (QTc) in healthy adults.Method:This study was a Phase 1, double-blind (except for the positive control moxifloxacin), randomized, 3-period, 6-sequence crossover design in healthy adult male and female subjects evaluating the electrocardiographic effects of SPN-812. Subjects were randomized to receive a sequence of all 3 treatments – placebo, 400 mg moxifloxacin (positive control), and 1800 mg SPN-812 (supratherapeutic dose). Treatment was given for 2 consecutive days (separated by a washout of at least 4 days). The primary endpoint was based on concentration-QTc effect modeling, evaluating the relationship between plasma concentrations of SPN-812 and its metabolite 5-hydroxyviloxazine glucuronide (5-HVLX-gluc) with the placebo-adjusted change from baseline in QTcI, ΔΔQTcI (QT interval corrected for HR based on the individual-specific QT interval correction method). Secondary endpoints included time point change from baseline in QTcI, QTcF, HR, PR, and QRS; evaluation of the relationship between the plasma concentration of viloxazine and 5-HVLX-gluc and the placebo-adjusted change from baseline in HR, PR, QRS, and QTcF; evaluation of the relationship between the plasma concentration of moxifloxacin and ΔΔQTcI to demonstrate assay sensitivity; and changes in ECG morphology. Safety endpoints included assessment of adverse events and other parameters.Results:The relationship between ΔΔQTcI and viloxazine plasma concentration demonstrated a negative slope (p=0.0012). Predicted mean ΔΔQTcI (2-sided 90% CI) for SPN-812 was -9.7 ms (-11.3, -8.1) at the mean Cmax of 12.4 μg/mL. The relationship of 5-HVLX-gluc and ΔΔQTcI similarly demonstrated a predicted negative slope (p=0.0007) with a predicted mean ΔΔQTcI (2-sided 90% CI) of -9.2 ms (-10.8, -7.8) at the mean Cmax of 10.0 μg/mL. Assay sensitivity was confirmed. Concentration-effect modeling demonstrated no relationship between plasma concentrations of viloxazine and 5-HVLX-gluc and other ECG parameters. The secondary time point analyses demonstrated no effect of SPN-812 on QTcI or other ECG intervals. SPN-812 produced no changes in ECG T wave or U wave morphology.Conclusions:Data from this Phase 1 thorough QT study demonstrate that a supratherapeutic dose of SPN-812, 1800 mg QD, has no effect on cardiac repolarization or other ECG parameters, and is thus not associated with a risk for cardiac arrhythmias such as TdP.Funding Acknowledgements:This research was funded by Supernus Pharmaceuticals, Inc., Rockville, MD.

Evaluation of the Effect of Contezolid (MRX-I) on the Corrected QT Interval in a Randomized, Double-Blind, Placebo- and Positive-Controlled Crossover Study in Healthy Chinese Volunteers

ABSTRACT Contezolid (MRX-I), a new oxazolidinone, is an antibiotic in development for treating complicated skin and soft tissue infections caused by resistant Gram-positive bacteria. This was a thorough QT study conducted in 52 healthy subjects who were administered oral contezolid at a therapeutic (800 mg) dose, a supratherapeutic (1,600 mg) dose, placebo, and oral moxifloxacin at 400 mg in four separate treatment periods. The pharmacokinetic profile of contezolid was also evaluated. Time point analysis indicated that the upper bounds of the two-sided 90% confidence interval (CI) for placebo-corrected change-from-baseline QTc (ΔΔQTc) were <10 ms for the contezolid therapeutic dose at each time point. The upper bound of the 90% CI for ΔΔQTc was slightly more than 10 ms with the contezolid supratherapeutic dose at 3 and 4 h postdose, and the prolongation effect on the QT/QTc interval was less than that of the positive control, moxifloxacin, at 400 mg. At 3 and 4 h after the moxifloxacin dose, the moxifloxacin group met the assay sensitivity criteria outlined in ICH Guidance E14 by having a lower confidence bound of ≥5 ms. The results of a linear exposure-response model which were similar to that of a time point analysis demonstrated a slightly positive relationship between contezolid plasma levels and ΔQTcF interval with a slope of 0.227 ms per mg/liter (90% CI, 0.188 to 0.266). In summary, contezolid did not prolong the QT interval at a therapeutic dose and may have a slight effect on QT interval prolongation at a supratherapeutic dose.

Tranexamic Acid Failed to Reverse the Anticoagulant Effect and Bleeding by an Oral Direct Factor Xa Inhibitor Edoxaban

Background/Aims: Agents to reverse the anticoagulant effect of edoxaban, an oral direct factor Xa inhibitor, would be desirable in emergency situations. The aim of this study is to determine the effect of tranexamic acid, an antifibrinolytic agent, on the anticoagulant activity and bleeding by edoxaban in rats. Methods: A supratherapeutic dose of edoxaban (3 mg/kg) was intravenously administered to rats. Three minutes after dosing, tranexamic acid (100 mg/kg) was given intravenously. Bleeding was induced by making an incision with a blade on the planta 8 min after edoxaban injection and bleeding time was measured. Prothrombin time (PT) and clot lysis were examined. Results: A supratherapeutic dose of edoxaban significantly prolonged PT and bleeding time. Tranexamic acid did not affect PT or bleeding time prolonged by edoxaban, although tranexamic acid significantly inhibited clot lysis in rat plasma. Conclusion: An antifibrinolytic agent tranexamic acid failed to reverse the anticoagulant effect and bleeding by edoxaban in rats.