The U.S. Food and Drug Administration (FDA) has approved Milestone Pharmaceuticals Inc.’s first commercial product, the Cardamyst (etripamil) nasal spray, on March 15, 2024. This approval allows for the treatment of acute symptomatic episodes of paroxysmal supraventricular tachycardia (PSVT) in adults, marking a significant advancement for the more than 2 million Americans living with this condition. Cardamyst is expected to be available in retail pharmacies in the first quarter of 2026.
Significance of Cardamyst’s Approval
The approval of Cardamyst is particularly noteworthy as it is the first new treatment option for PSVT in over three decades. PSVT is a type of arrhythmia characterized by the rapid beating of the heart’s upper chambers, which can lead to symptoms such as palpitations, dizziness, shortness of breath, and chest pain. The nasal spray provides a novel approach as a rapid-acting calcium channel blocker that can be self-administered during sudden episodes, offering patients a way to regain sinus rhythm quickly.
Clinical trial data underpinning the FDA’s decision showcases the efficacy of Cardamyst. The approval is based on safety data from over 1,800 participants and more than 2,000 episodes of PSVT. In clinical studies, those using Cardamyst were found to be twice as likely to convert symptomatic PSVT to sinus rhythm compared to those receiving a placebo, achieving this conversion more than three times faster.
Clinical Trial Results
The RAPID trial, a pivotal study supporting the approval, achieved its primary endpoint with impressive results. Within 30 minutes, 64% of participants who self-administered Cardamyst (N=99) converted from supraventricular tachycardia (SVT) to sinus rhythm, in stark contrast to just 31% of those on placebo (N=85). At the one-hour mark, this benefit increased to 73% for Cardamyst users.
The median time to conversion for those treated with Cardamyst was 17 minutes, compared to 54 minutes for the placebo group. These early and consistent reductions in conversion time demonstrate the potential impact of Cardamyst on the management of PSVT.
The news of the approval positively influenced Milestone Pharmaceuticals’ stock, with shares rising by 30.73% to $3.15 during premarket trading, reaching a new 52-week high, according to Benzinga Pro data.
Milestone Pharmaceuticals’ achievement with Cardamyst underscores the ongoing need for effective treatments for arrhythmias and highlights the potential for innovation in cardiovascular care. With the anticipated availability of Cardamyst by early 2026, patients may soon have access to a much-needed therapeutic option for managing their condition.
