Milestone Pharmaceuticals Announces Plan to Resubmit NDA for Etripamil for the Treatment of PSVT

Resubmission of NDA expected 2Q2024

Operating Runway Extended Into Mid-2025 with Cash Conservation Measures

MONTREAL and CHARLOTTE, N.C., Feb. 26, 2024 (GLOBE NEWSWIRE) -- Milestone Pharmaceuticals Inc. (Nasdaq: MIST) today announced plans to resubmit the New Drug Application (NDA) for etripamil to the U.S. Food and Drug Administration (FDA) for paroxysmal supraventricular tachycardia (PSVT).

Following the previously announced receipt of a Refusal to File letter, Milestone held a Type A Meeting with FDA. FDA indicated that the timing of adverse events (AEs) in question had minimal impact on the overall characterization of the etripamil safety profile. To align with FDA’s guidance, the Company will restructure the data sets that capture timing of reported AEs, reformat certain data files to facilitate FDA’s analyses, and resubmit the NDA. Based on the guidance received during the Type A Meeting, the Company expects that this approach will address the Refusal to File letter from FDA. FDA has not requested that the Company complete additional clinical efficacy or safety trials prior to resubmitting the NDA. The Company expects a standard NDA review period following resubmission of the NDA for etripamil for PSVT, which is planned for 2Q2024.

"We thank FDA for its thoughtful consideration of our materials and direction on the NDA resubmission," said Joseph Oliveto, President, and Chief Executive Officer of Milestone Pharmaceuticals. "The feedback we continue to receive from key stakeholders, including patients and health care providers, reinforces our belief that etripamil nasal spray has the potential to be a valuable new option for patients with PSVT that may establish a new standard of care, if approved. We are committed to working with FDA to bring this potentially important new treatment to patients and our recent meeting underscores this commitment.”

Considering the revised timeline for NDA submission, the Company has undertaken certain cash conservation measures to reduce spend through program deferrals and team restructuring and expects that the Company’s existing cash resources will fund operations into mid-2025, including the expected
Prescription Drug User Fee Act (PDUFA) date for the NDA resubmission. If FDA approval is granted, the Company expects to receive a $75 million payment under an existing royalty agreement, which is intended to fund the potential commercial launch of etripamil for PSVT.

About Paroxysmal Supraventricular Tachycardia (PSVT)

An estimated two 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 sudden onset rapid heartbeats often exceeding 150 to 200 beats per minute. The heart rate spike is unpredictable and may last several hours. The rapid heart rate often causes disabling 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 health care providers are dissatisfied with the lack of effective treatment options with patients often requiring prolonged, burdensome, and costly trips to the emergency department or even invasive cardiac ablation procedures.