Etripamil Nasal Spray for Recurrent Paroxysmal Supraventricular Tachycardia Conversion: Results From the NODE-303 Open-Label Study.

Introduction: Etripamil is a fast-acting intranasally self-administered calcium-channel blocker developed for termination of paroxysmal supraventricular tachycardia (PSVT). Prior studies have demonstrated safety and efficacy of etripamil for PSVT termination following an initial medically supervised test dose during sinus rhythm. NODE-303 is an open-label, single-arm study that evaluated etripamil for multiple, at-home PSVT episodes, without test dose before first use.

Methods: Patients applied an ECG monitor at symptom onset and self-administered etripamil (70 mg) if a vagal maneuver was unsuccessful. ECG monitoring occurred for ≥ 1 h following study drug administration. A repeat 70-mg dose was introduced during the study for symptoms persisting 10 min after the first dose. Safety measures included treatment-emergent adverse events (TEAEs) and ECG arrhythmia-surveillance. Efficacy measures were captured for PSVT termination during treatment of each of the multiple episodes.

Results: 1054 perceived PSVT episodes were etripamil-treated in 503 of 1116 patients enrolled. TEAEs within 24 h were mostly mild or moderate and localized: 30.2% of patients experienced nasal discomfort, nasal congestion (13.9%), rhinorrhea (13.1%), epistaxis (7.4%). TEAE frequencies decreased across multiple PSVT episodes and were similar for single versus repeat doses. For first PSVT episodes, 70.5% of patients converted to sinus rhythm by 60 min post etripamil (median time to conversion = 18.3 min [14.2-25.6]). Conversion in earlier episodes was consistently predictive of conversion in subsequent episodes.

Conclusions: Etripamil nasal spray self-administered in a real-world setting was well tolerated, effective, and had a consistent safety profile as a single- or repeat-dose regimen across multiple PSVT episodes.

Trial registration: ClinicalTrials.gov NCT04072835.