• Submission seeks approval for treatment of an abnormal heart rhythm, Paroxysmal Supraventricular Tachycardia or PSVT
  • Comprehensive data package includes positive results from pivotal Phase 3 RAPID trial which Company believes demonstrates new calcium channel blocker, etripamil, is twice as effective and three times as fast as a placebo in restoring normal heart rhythm for patients suffering from PSVT
  • 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 treatment of serious heart arrhythmias

MONTREAL, Canada and CHARLOTTE, NC, USA I October 24, 2023 I Milestone® Pharmaceuticals Inc. (Nasdaq: MIST) today announced the submission of a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) for etripamil for the treatment of paroxysmal supraventricular tachycardia (PSVT). PVST is a condition characterized by an abnormality in the electrical system of the heart causing patients to have unexpected, often severely symptomatic episodes of rapid heart rate.

Representing the largest data package ever studied in PSVT, the Company believes the clinical trial program demonstrates that etripamil provided superior time to conversion to normal heart rhythm compared to placebo. The primary analysis and supportive assessments from the pivotal RAPID Phase 3 clinical trial were recently published in The Lancet.

“With the achievement of our first NDA submission, we want to thank the investigators, clinical trial teams, our colleagues and, most importantly, patients whose contributions were critical to completing our registration trials,” said Joseph Oliveto, President, and Chief Executive Officer of Milestone Pharmaceuticals. “With this submission, we are one step closer to getting etripamil into the hands of patients who are seeking a new treatment option that will allow them to take an active role in managing their PSVT.”

The FDA has a 60-day filing review period to determine whether the NDA is complete and accepted for review. If accepted, Milestone Pharmaceuticals expects a standard review of 10 months of the company’s NDA. Milestone continues to advance commercial preparations to support the anticipated launch of etripamil with the proposed trade name, CARDAMYST™. The brand name is conditionally approved by the FDA.

About Pivotal RAPID Phase 3 Trial

Recently published in The Lancet, RAPID is a global, randomized, double-blind phase 3 clinical trial of etripamil versus placebo in patients with PSVT. The trial was designed to evaluate the safety and efficacy of self-administered etripamil for treating PSVT. The RAPID trial achieved its primary endpoint with 64% of patients who self-administered etripamil converting from supraventricular tachycardia (SVT) to sinus rhythm within 30 minutes compared to 31% on placebo (HR = 2.62, p<0.001). At one hour, the benefit was demonstrated in 73% of patients. In addition, significant reductions in time to conversion in patients who took etripamil were evident early and durable, with a median time to conversion of 17 minutes (95% CI: 13.4, 26.5) for patients treated with etripamil versus 54 minutes (95% CI: 38.7, 87.3) for patients treated with placebo. Data demonstrated statistically significant improvement in multiple defined symptoms of PSVT in patients receiving  etripamil compared to placebo, using a patient-reported outcome (PRO) questionnaire. The safety and tolerability profile of etripamil is supportive of the NDA submission.

About Paroxysmal Supraventricular Tachycardia (PSVT)

An estimated 2 million people in the United States are currently diagnosed with PSVT which is a type of arrhythmia or abnormal heart rhythm. PSVT is characterized by episodes of rapid heartbeats often exceeding 150 to 200 beats per minute. Key features of PSVT include the sudden occurrence of episodes and very rapid heart rate. The heart rate can spike unpredictably and rapidly during an episode. The rapid heart rate often causes severe palpitations, shortness of breath, chest discomfort, dizziness, or lightheadedness, and distress, forcing patients to limit their daily activities. The uncertainty of when an episode of PSVT will strike or how long it will persist can provoke anxiety in patients and negatively impact their day-to-day life between episodes. The impact and morbidity from an attack can be especially detrimental in patients with underlying cardiovascular or medical conditions, such as heart failure, obstructive coronary disease, or dehydration. Many doctors are dissatisfied with the lack of effective treatment options in addition to a prolonged, burdensome, and costly trip to the emergency department or, for some patients, an invasive ablation procedure.

About Etripamil 

Etripamil is Milestone’s lead investigational product. It is a novel calcium channel blocker nasal spray being developed for elevated and often highly symptomatic heart-rate attacks associated with PSVT and atrial fibrillation with a rapid ventricular rate (AFib-RVR). It is designed to be a rapid-response therapy that is self-administered by the patient, without the need for direct medical oversight. If approved, etripamil is intended to provide health care providers with a new treatment option to enable virtual care and patient self-management. If approved, the portable treatment, studied as self-administered, may provide patients with active management and a greater sense of control over their condition. Etripamil, proposed brand name CARDAMYST™, is well studied with a robust clinical trial program that includes a completed Phase 3 clinical-stage program for the treatment of PSVT and soon-to-be-reported Phase 2 proof-of-concept trial for the treatment of patients with AFib-RVR.

About Milestone Pharmaceuticals

Milestone Pharmaceuticals Inc. (Nasdaq: MIST) is a biopharmaceutical company focused on the development and commercialization of innovative cardiovascular medicines. Milestone’s lead product candidate etripamil recently completed its Phase 3 clinical-stage program for the treatment of PSVT and is in a Phase 2 proof-of-concept trial for the treatment of patients with AFib-RVR. The AFib-RVR study, ReVeRA, was selected for a Featured Science presentation at the American Heart Association (AHA) Scientific Sessions 2023. Milestone Pharmaceuticals operates in Canada and the United States. Find out more at www.milestonepharma.com.

SOURCE: Milestone Pharmaceuticals