Milestone: Etripamil ‘effective’ at restoring sinus rhythm in trial

Milestone Pharmaceuticals announced new clinical data demonstrating real-world application of etripamil, an investigational new drug, for conversion of recurrent paroxysmal supraventricular tachycardia. Conducted in North and South America, this open label, Phase 3 study of etripamil in PSVT was both presented at The American College of Cardiology Scientific Sessions in Atlanta, GA and published in The Journal of the American College of Cardiology. CARDAMYST, the conditionally approved brand name for etripamil nasal spray, if approved, will be the first rapid, reliable, and at-the-ready option in the acute treatment of PSVT. NODE-303 evaluated self-administered etripamil in an outpatient setting for up to multiple episodes of PSVT, without prior test dosing. It did not exclude patients with a history of co-morbid atrial fibrillation or atrial flutter. The results demonstrated that symptom-prompted treatment with etripamil was effective at restoring sinus rhythm as compared to placebo with a median time-to-conversion of 17.0 minutes and was generally well tolerated. The conversion of PSVT to sinus rhythm was similar among multiple PSVT episodes and the frequency of treatment-emergent adverse events at 24 hours decreased with successive episodes. Adverse events were predominantly localized to the drug’s nasal administration site, consistent with prior trial findings. The protocol was amended during the trial to allow for a repeat dose of drug if symptoms persisted 10 minutes following the first dose. Efficacy of etripamil for PSVT conversion in NODE-303 was 60% by 30 minutes after drug self-administration, and 69.9% by 60 minutes after drug self-administration; these rates of conversion are similar to those demonstrated in double-blinded and other open-label studies. These data support a potentially significant shift in the management approach for recurrent PSVT.