Milestone’s CARDAMYST Nasal Spray Wins FDA Approval, Shares Soar 34%

Introduction

Milestone Pharmaceuticals Inc (NASDAQ: MIST) is a Montreal-based clinical-stage biopharmaceutical company focused on self-administered treatments for episodic cardiovascular conditions. Established in 2007, the company’s lead asset is etripamil, a short-acting nasal spray designed to terminate acute paroxysmal supraventricular tachycardia (PSVT) episodes outside of a healthcare setting.

Corporate Structure

Milestone Pharmaceuticals maintains a workforce of 11–50 employees. Its executive leadership comprises individuals with experience from both major pharmaceutical and emerging life sciences firms, guiding programs in PSVT, atrial fibrillation with rapid ventricular rate (AFib-RVR), and angina. The company operates from its headquarters in Montreal, Quebec, and tailors its web content by region to ensure compliance with local regulations.

Cardiovascular treatment by Philip Oroni

Recent Developments and News

• FDA Approval of CARDAMYST
  On December 10, 2025, the U.S. Food and Drug Administration approved CARDAMYST™ (etripamil) nasal spray. This is the first FDA-approved self-administered treatment for adults experiencing acute PSVT episodes.
• AHA Presentation
  On November 10, 2025, Dr. James Ip is scheduled to present “Combined Efficacy, Safety, and Test Dose Tolerability of Etripamil for Acute Paroxysmal Supraventricular Tachycardia (PSVT)” at the American Heart Association Scientific Sessions (AHA2025) in Chicago.
• Phase 2 Trial Plans
  Milestone intends to initiate a Phase 2 clinical trial of etripamil in atrial fibrillation and subsequently in angina to establish proof-of-concept beyond PSVT.
• Community Engagement
  On September 27, 2025, Milestone’s team participated in the American Heart Association Heart Walk in Charlotte, highlighting its involvement in community outreach.

Financial and Strategic Aspects

As of December 15, 2025, Milestone’s shares closed at $3.23, reflecting a 34.02% increase on a volume of 5,904,875 on NASDAQ. Institutional investors hold significant stakes:

• Trails Edge Capital Partners, LP – 9,017,880 shares (≈9.9%)
• RTW Investments, LP – 9,155,168 shares (≈9.9%)
• Adage Capital Management, L.P. – 8,659,064 shares (≈9.99%), including 1,683,064 shares issuable upon warrant exercise

Strategically, Milestone is in the process of deploying 60 field representatives in the first quarter of 2026 to engage with approximately 15,000 high-volume prescribers, aiming to promote early adoption of CARDAMYST.

Market Position and Industry Context

Milestone occupies a position as the first company to offer a self-administered, rapid-onset PSVT treatment in over 30 years. The addressable market includes more than two million adults in the U.S. who experience PSVT annually. The company's pipeline includes further developments targeting AFib-RVR and angina, addressing additional episodic cardiovascular markets. Operating within the biotechnology research sector, Milestone must navigate regulatory reviews, competitive innovation, and reimbursement dynamics typical of specialty pharmaceuticals.

tl;dr

• FDA approved CARDAMYST™ nasal spray for PSVT on December 10, 2025.
• Presentation on etripamil’s clinical data is scheduled for AHA2025 on November 10, 2025.
• Q1 2026 launch plans include 60 sales representatives targeting 15,000 prescribers.
• Phase 2 trials in AFib and angina are planned following PSVT commercialization.
• Institutional investors hold approximately 9.9% of the company’s shares, with warrants potentially affecting equity structure.