Cardiovascular and Pharmacokinetic Profiles of Intravenous Etripamil in Conscious Telemetered Cynomolgus Monkeys

Paroxysmal supraventricular tachycardia (PSVT) is a common cardiac arrhythmia associated with substantial health care burden. Etripamil, a fast-acting non-dihydropyridine calcium channel blocker developed for intranasal self-administration, is currently under investigation for acute treatment of PSVT episodes. A novel two-phase study design was used to test a series of five doses of intravenous etripamil (0, 0.025, 0.05, 0.15, and 0.3 mg/kg) in conscious cynomolgus monkeys. The cardiovascular effects (e.g., blood pressure and ECG recordings) were assessed during the first phase, and the pharmacokinetic profile was characterized during the second phase. Animals were dosed remotely to avoid the stress of intranasal dosing and minimize the impact of dose administration on measurements. Results were compared with findings from subsequent intranasal studies in cynomolgus monkeys and humans. Etripamil decreased systolic blood pressure and increased heart rate proportionately in a dose-dependent manner. Etripamil also induced dose-dependent increases in the PR interval. At a dose of 0.3 mg/kg (the highest dose), the mean highest PR prolongation from baseline during 20 minutes after dosing was 27.38%. Systemic exposure to etripamil increased in a dose-dependent manner. Mean area under the curve from administration to when drug was no longer present (AUC_0-∞) values ranged from 179 to 2364 ng • min/mL, peak plasma concentration ranged from 13.2 to 176 ng/mL, and mean half-life ranged from 12.3 to 20.8 minutes (Figure 1). Results were consistent with data from subsequent intranasal preclinical and clinical studies. Intravenous etripamil demonstrated the desired targeted pharmacokinetic and pharmacodynamic profiles in conscious cynomolgus monkeys.