Milestone Pharmaceuticals (NASDAQ: MIST) announced the enrollment of its first Canadian patient in the ReVeRA-301 Phase 3 trial, conducted at the Montreal Heart Institute. The multinational, multicenter, randomized, double-blind, placebo-controlled study targets 150 patients experiencing atrial fibrillation with rapid ventricular rate (AFib-RVR).
The trial evaluates etripamil nasal spray using a 70 mg repeat-dose regimen. Patients self-administer the treatment in unsupervised settings, such as their homes, when prompted by symptoms. The primary endpoint measures reduction in ventricular rate within 30 minutes of administration; a key secondary endpoint assesses symptom improvement through patient-reported outcomes.
Milestone is pursuing a single-study supplemental new drug application registration pathway for AFib-RVR treatment, relying on safety data demonstrated to date. The 70 mg repeat-dose regimen being tested received U.S. Food and Drug Administration approval earlier for paroxysmal supraventricular tachycardia under the brand name CARDAMYST nasal spray.
The company estimates that 30–40% of patients with atrial fibrillation experience at least one episode of rapid ventricular rate per year requiring urgent medical attention. The Canadian Cardiovascular Society estimates AFib affects approximately 1–2% of Canada’s population, or up to 800,000 people.
ReVeRA-301 follows the ReVeRA-201 Phase 2 study, which was conducted in emergency room settings.
