Milestone Pharmaceuticals Inc (NASDAQ: MIST) shares gained 3.9% on Friday after the company announced the first patient enrollment in its Phase 3 ReVeRA-301 trial evaluating etripamil for atrial fibrillation with rapid ventricular rate (AFib-RVR).
The multinational, multi-center, randomized, double-blind, placebo-controlled study will enroll approximately 150 patients and assess the primary endpoint of ventricular rate reduction within 30 minutes of treatment. A key secondary endpoint measures symptom improvement using patient-reported outcomes. Patients will self-administer the 70 mg repeat-dose regimen of etripamil in medically unsupervised settings, such as at home.
Milestone is pursuing a single-study supplemental new drug application pathway for regulatory approval of etripamil in AFib-RVR treatment. The drug, marketed as CARDAMYST nasal spray, previously received FDA approval for paroxysmal supraventricular tachycardia (PSVT) using the same dosing regimen.
Phase 2 trial data from the ReVeRA-201 study demonstrated that a single 70 mg dose of etripamil reduced ventricular rate and improved symptom relief and treatment satisfaction in AFib-RVR patients within an emergency room setting. The company aims to replicate these findings in the Phase 3 trial.
Atrial fibrillation affects over 6 million patients in the United States, with 30-40% experiencing at least one episode of rapid ventricular rate requiring urgent medical attention annually. The American Heart Association projects the total U.S. economic burden of AFib to rise from $59.4 billion in 2020 to $174.8 billion by 2050, with direct healthcare costs increasing from $54.8 billion to $167.3 billion over the same period (all figures in 2022 U.S. dollars).
