FDA Approves Etripamil (Cardamyst) Nasal Spray for PSVT

Announced by parent company Milestone Pharmaceuticals on December 12, 2025, the US Food and Drug Administration (FDA) has approved etripamil (Cardamyst) nasal spray for the conversion of acute symptomatic episodes of paroxysmal supraventricular tachycardia (PSVT) to sinus rhythm in adults.1

The decision marks the first time that more than 2 million people in the US with PSVT will have a rapid-acting treatment option they can self-administer outside the emergency department or other healthcare setting. As described in the release from Milestone, etripamil is expected to be available in retail pharmacies in the first quarter of 2026.1

“Some people with PSVT have endured years of anxiety, fearing their next episode and the stress and disruption of emergency department visits,” James Ip, MD, an etripamil investigator, said in a statement.1 “CARDAMYST will give many of them the ability to administer a medication themselves that can quickly stop their PSVT episode and potentially avoid a hospital trip or a call to emergency services.”

Etripamil is a novel calcium channel blocker nasal spray developed to treat frequent and highly symptomatic episodes of paroxysmal supraventricular tachycardia (PSVT). It is designed as a rapid response therapy to be self-administered by patients, bypassing the need for medical oversight. It offers patients more control over their condition via active management.2

Etripamil’s efficacy has been proven across various trials in the overarching NODE program, including the NODE-1, NODE-301 parts 1 and 2, NODE-302, and NODE-303 trials. A collective analysis of all of these trials was presented at the American Heart Association’s 2025 Scientific Sessions in November 2025, which highlighted the overall efficacy, safety, and test-dose tolerability of etripamil in patients with PSVT.3

During this collective analysis, efficacy measures included the proportion of patients converting from PSVT to normal sinus rhythm (SR) within 30 minutes and the median times to conversion across all the included phase 3 studies. Safety data for treatment-emergent adverse events (TEAEs), serious adverse events, and test dose tolerability from phase 2 and 3 studies were also summarized.3

The Kaplan-Meier estimate during this analysis displayed a substantial 59.6% of patients exposed to etripamil converted to normal SR within 30 minutes, with a median time to conversion of 18.5 minutes (95% CI, 15.7-21). The proportions of placebo group patients converting from SVT to SR by 30 minutes ranged from 26.7% to 34.7%, while estimates of conversion with etripamil at 60 minutes for the individual studies ranged from 63.2% to 73.5%.3

Additionally, the combined analysis displayed largely mild and transient treatment-emergent adverse events, primarily nasal congestion, nasal discomfort, throat irritation, rhinorrhea, and epistaxis. A total of 1107 patients took ≥1 etripamil test dose while in SR, and no significant change in average baseline heart rate or blood pressure was observed within 45 minutes of administration. Test dose failure occurred in only 1.4% of patients (n = 16). Investigators determined no need for a pretreatment dose, highlighting etripamil’s favorable tolerability.3

“CARDAMYST is a novel at-the-ready treatment option that addresses the unpredictable impact of PSVT by offering patients the freedom to manage episodes anytime and anywhere,” said Joseph Oliveto, President and Chief Executive Officer of Milestone Pharmaceuticals.1 “The FDA approval of CARDAMYST is a watershed moment for Milestone and a gratifying event for our team members, patients, clinical investigators, and health care providers who participated in the development program, all of whom I sincerely thank for their dedication, counsel, and collaboration toward this important achievement.”

References

1. Milestone Pharmaceuticals. Milestone Receives FDA Approval of CARDAMYST™ (etripamil) as First and Only Self-Administered Nasal Spray for Adults with Paroxysmal Supraventricular Tachycardia (PSVT). December 12, 2025. Accessed December 12, 2025. https://www.globenewswire.com/news-release/2025/12/13/3204944/0/en/Milestone-Receives-FDA-Approval-of-CARDAMYST-etripamil-as-First-and-Only-Self-Administered-Nasal-Spray-for-Adults-with-Paroxysmal-Supraventricular-Tachycardia-PSVT.html

2. 2. Gardner K. Milestone Pharmaceuticals Announces FDA Acceptance of the Company’s Response to the CRL for CARDAMYST (etripamil) Nasal Spray. Milestone Pharmaceuticals. July 11, 2025. Accessed December 9, 2025. https://investors.milestonepharma.com/news-releases/news-release-details/milestone-pharmaceuticals-announces-fda-acceptance-companys

3. 3. Ip J, Noseworthy P, Piccini J, et al. Combined Efficacy, Safety, and Test Dose Tolerability of Etripamil for Acute Paroxysmal Supraventricular Tachycardia (PSVT) Across Multiple Clinical Trials. AHA/ASA Journals. November 3, 2025. Accessed December 9, 2025. https://www.ahajournals.org/doi/10.1161/circ.152.suppl_3.4366812