This section highlights FDA-related milestones and regulatory updates for drugs developed by Milestone Pharmaceuticals (MIST).
Over the past two years, Milestone Pharmaceuticals has reported clinical trial outcomes, regulatory submissions, approvals, and other FDA events for drugs and therapies such as
Etripamil and ReVeRA-301. For definitions of regulatory abbreviations such as NDA, BLA, or PDUFA, see the event status legend.
Select a button below to view the list of FDA events for that drug.
Etripamil FDA Regulatory Timeline and Events
Etripamil is a drug developed by Milestone Pharmaceuticals for the following indication: For Treatment in Paroxysmal Supraventricular Tachycardia.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- Etripamil
- Announced Date:
- October 19, 2026
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Milestone® Pharmaceuticals Inc announced that data and program updates for CARDAMYST® (etripamil) nasal spray for its approved PSVT indication and on etripamil nasal spray for an investigational indication will be presented at three upcoming cardiovascular medical meetings
Read Announcement- Drug:
- Etripamil
- Announced Date:
- September 3, 2026
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Milestone® Pharmaceuticals Inc announced that China’s National Medical Products Administration (NMPA) has approved etripamil nasal spray for the treatment of paroxysmal supraventricular tachycardia (PSVT) in adults. Etripamil, marketed in the United States as CARDAMYST® nasal spray, is a self-administered treatment for adults with PSVT.
Read Announcement- Drug:
- Etripamil
- Announced Date:
- August 20, 2026
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Milestone® Pharmaceuticals Inc. announced that the first patient has been enrolled in the Phase 3 ReVeRA-301 pivotal trial evaluating etripamil for atrial fibrillation with rapid ventricular rate (AFib-RVR).
Read Announcement- Drug:
- Etripamil
- Announced Date:
- March 31, 2026
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Milestone® Pharmaceuticals Inc. announced that Express Scripts, one of the nation's largest pharmacy benefit managers, has added CARDAMYST™ (etripamil) nasal spray to its commercial national formularies, effective March 27, 2026.
AI Summary
Milestone Pharmaceuticals announced that Express Scripts has added CARDAMYST™ (etripamil) nasal spray to its commercial national formularies, effective March 27, 2026. Inclusion on a major pharmacy benefit manager’s national formularies can expand access for many patients and make coverage decisions more consistent across plans managed by Express Scripts.
CARDAMYST is a prescription, self‑administered nasal spray used to convert acute symptomatic episodes of paroxysmal supraventricular tachycardia (PSVT) to normal sinus rhythm in adults. As an at‑home nasal option, it offers an alternative to some emergency or clinic‑based interventions for sudden fast heart rhythms.
The formulary listing may lower barriers such as prior authorization or high out‑of‑pocket costs for covered patients, though specific coverage rules and copays will vary. Patients should check benefits with their plan and consult their healthcare provider about whether CARDAMYST is appropriate, how to use it, and its possible side effects.
Read Announcement- Drug:
- Etripamil
- Announced Date:
- March 16, 2026
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Milestone® Pharmaceuticals Inc. announced that a moderated poster presentation titled "Minimal Blood Pressure Effects of Intranasal Etripamil in Trials for Paroxysmal Supraventricular Tachycardia (PSVT)" will be featured at the 2026 American College of Cardiology Annual Scientific Session (ACC.26), March 28-30th in New Orleans, La. An Expert Theater will also be conducted at ACC.26, providing a deeper look at this new treatment option for adults with symptomatic PSVT.
AI Summary
Milestone Pharmaceuticals announced a moderated poster presentation titled "Minimal Blood Pressure Effects of Intranasal Etripamil in Trials for Paroxysmal Supraventricular Tachycardia (PSVT)" will be featured at the 2026 American College of Cardiology Annual Scientific Session (ACC.26), March 28–30 in New Orleans. The poster will present trial data on intranasal etripamil (CARDAMYST) and its limited impact on blood pressure in adults treated for PSVT.
An Expert Theater at ACC.26 will offer a deeper look at this new treatment option for adults with symptomatic PSVT. Attendees can learn more about CARDAMYST at Booth #319. CARDAMYST is indicated for conversion of acute symptomatic PSVT to sinus rhythm in adults and is a prescription medicine; its safety and effectiveness in children are not known. For full prescribing information, safety details, and potential side effects, consult the official prescribing information: https://milestonepharma.com/etripamilprescribinginformation.pdf and speak with a healthcare provider.
Read Announcement- Drug:
- Etripamil
- Announced Date:
- January 26, 2026
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Milestone Pharmaceuticals Inc. announced that CARDAMYST™ (etripamil) nasal spray, its first commercial product, is now available through U.S. retail pharmacies. CARDAMYST is a prescription medication indicated for the conversion of acute symptomatic episodes of paroxysmal supraventricular tachycardia (PSVT) to sinus rhythm in adults. Implementation of a rapid commercialization plan is underway with a national sales force to be deployed in mid-February 2026.
AI Summary
Milestone Pharmaceuticals said CARDAMYST™ (etripamil) nasal spray is now available at U.S. retail pharmacies. CARDAMYST is a prescription, self‑administered nasal spray for adults to convert acute symptomatic episodes of paroxysmal supraventricular tachycardia (PSVT) to normal heart rhythm, offering a portable option for on‑demand care.
The company has launched a rapid commercialization plan and will deploy a national sales force in mid‑February 2026. Milestone is working with insurers for formulary placement and coverage while rolling out promotional and provider outreach efforts to support the launch.
Launch support includes a patient assistance platform that provides benefits verification, reimbursement help, and copay assistance. For eligible commercially insured patients, copays are expected to be capped at $25, aiming to reduce financial and administrative barriers and make treatment more accessible.Read Announcement
- Drug:
- Etripamil
- Announced Date:
- January 6, 2026
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Milestone® Pharmaceuticals Inc. announced the acceptance of a Marketing Authorization Application (MAA) by the European Medicines Agency (EMA) seeking the approval of etripamil nasal spray, developed to be the first rapid, reliable option in the treatment of paroxysmal supraventricular tachycardia (PSVT) outside of the healthcare setting.
AI Summary
Milestone Pharmaceuticals announced that the European Medicines Agency (EMA) has accepted its Marketing Authorization Application (MAA) for etripamil nasal spray, developed as a self‑administered, rapid treatment for paroxysmal supraventricular tachycardia (PSVT) outside the healthcare setting. The product carries the brand name TACHYMIST in Europe. A regulatory decision is expected by the first quarter of 2027. If approved, etripamil aims to become the first reliable on‑demand nasal therapy for patients who experience sudden, fast heart rhythms, potentially reducing emergency visits and giving patients quicker control over episodes.
The MAA is supported by a large clinical program with more than 1,800 participants and the Phase 3 RAPID trial. In RAPID, 64% of people who self‑administered etripamil converted to normal rhythm within 30 minutes versus 31% on placebo, with median times to conversion of 17 versus 54 minutes. Reported side effects were mostly mild and nasal in nature, and fewer than 2% discontinued due to adverse events.
Read Announcement- Drug:
- Etripamil
- Announced Date:
- December 17, 2025
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Aptar Group, Inc. announced that its Bidose (BDS) Liquid Nasal Spray System is the mechanism for delivering the newly approved CARDAMYST™ (etripamil) Nasal Spray. CARDAMYST received approval by the U.S. Food and Drug Administration (FDA) for the conversion of acute symptomatic episodes of paroxysmal supraventricular tachycardia (PSVT) to sinus rhythm in adults. The novel treatment was developed by Milestone® Pharmaceuticals Inc. (NASDAQ:MIST), a biopharmaceutical company focused on the development and commercialization of innovative cardiovascular medicines. This marks Aptar's first combination of dual Bidose delivery systems housed in a consumer-friendly protective two-pack container.
AI Summary
Aptar Group announced its Bidose (BDS) Liquid Nasal Spray System will deliver CARDAMYST™ (etripamil) nasal spray, which the U.S. Food and Drug Administration approved to convert acute symptomatic episodes of paroxysmal supraventricular tachycardia (PSVT) to sinus rhythm in adults. The medicine was developed by Milestone Pharmaceuticals.
This is Aptar’s first product combining two Bidose delivery mechanisms in a consumer-friendly protective two-pack container. Aptar and Milestone designed a custom polypropylene closure with an integrated cap to house two single-use sprays, help prevent accidental activation or dropping, and support reliable access when needed. Aptar noted its Bidose and Unidose platforms meet FDA quality standards and can support emergency-use treatments. The device is small enough for patients to carry and is intended for use as directed during sudden PSVT episodes. Aptar also provided development, regulatory and analytical support to help advance the combination product for patient use.
Read Announcement- Drug:
- Etripamil
- Announced Date:
- October 9, 2025
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Milestone® Pharmaceuticals Inc. announced that it will present a poster presentation at the American Heart Association Scientific Sessions 2025, to be held November 7-10th in New Orleans, Louisiana.
AI Summary
Milestone Pharmaceuticals Inc. will present a poster at the American Heart Association Scientific Sessions 2025 in New Orleans, Louisiana, from November 7–10. The company’s work focuses on a new self-administered form of etripamil for episodes of paroxysmal supraventricular tachycardia (PSVT).
Data to be shared include results on how well patients tolerate test doses of etripamil, alongside measures of its safety and ability to stop rapid heart rhythms during acute PSVT episodes. These findings come from multiple clinical trials.
The poster is titled “Combined Efficacy, Safety, and Test Dose Tolerability of Etripamil for Acute Paroxysmal Supraventricular Tachycardia (PSVT) Across Multiple Clinical Trials.”
James Ip, M.D., Associate Professor and Director of Cardiac Pacing and Implantable Devices at Weill Cornell Medicine and New York-Presbyterian Hospital, will present the research.
The session is scheduled for Monday, November 10, 2025, from 10:30 to 11:30 AM CST.
Read Announcement- Drug:
- Etripamil
- Announced Date:
- July 11, 2025
- Target Action Date:
- December 13, 2025
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Milestone® Pharmaceuticals Inc announced that The FDA has assigned a new Prescription Drug User Fee Act (PDUFA) target action date of December 13, 2025.
AI Summary
Milestone® Pharmaceuticals Inc. announced that the FDA has set a new PDUFA target action date of December 13, 2025 for its investigational drug CARDAMYST™ (etripamil nasal spray). The drug is being developed to treat paroxysmal supraventricular tachycardia (PSVT) and is designed for self-administration during rapid heart episodes. This updated timeline comes after Milestone submitted its response to address issues noted in a previous Complete Response Letter. The new date gives the FDA additional time to review the updated data and any further information the company provided. Milestone views this as a major milestone in its journey to bring CARDAMYST to market and is hopeful that the review process will lead to a positive approval decision, potentially offering a new treatment option for patients in need.
Read Announcement- Drug:
- Etripamil
- Announced Date:
- July 11, 2025
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Milestone® Pharmaceuticals Inc. announced that the U.S. Food and Drug Administration (FDA) has accepted for review Milestone's response to issues raised in the Complete Response Letter (CRL) for CARDAMYST™ (etripamil) nasal spray, an investigational, novel therapy for the treatment of patients with paroxysmal supraventricular tachycardia (PSVT).
AI Summary
Milestone® Pharmaceuticals Inc. announced that the U.S. Food and Drug Administration (FDA) has accepted its response to the issues raised in the Complete Response Letter for CARDAMYST™ (etripamil) nasal spray. This drug is an investigational, novel therapy designed for patients with paroxysmal supraventricular tachycardia (PSVT). With this acceptance, the FDA has set a new Prescription Drug User Fee Act (PDUFA) target action date of December 13, 2025, signaling a critical step toward the potential approval of the treatment.
Milestone sees this review as a significant milestone for CARDAMYST. The acceptance of their response to the FDA’s concerns moves them closer to launching a treatment that could offer patients a self-administered option for managing PSVT. This development underlines the company’s commitment to advancing new therapies and providing earlier treatment choices for patients in need.
Read Announcement- Drug:
- Etripamil
- Announced Date:
- June 16, 2025
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Milestone® Pharmaceuticals Inc announced submission of its response to the U.S. Food and Drug Administration (FDA)'s Complete Response Letter (CRL) regarding its New Drug Application (NDA) for CARDAMYST™ (etripamil) nasal spray, a prescription medication in development for the conversion of acute episodes of paroxysmal supraventricular tachycardia (PSVT) to sinus rhythm in adults.
AI Summary
Milestone® Pharmaceuticals Inc. announced that it has submitted its response to the U.S. Food and Drug Administration’s (FDA) Complete Response Letter for its New Drug Application for CARDAMYST™ (etripamil) nasal spray. This prescription medication is being developed to convert acute episodes of paroxysmal supraventricular tachycardia (PSVT) to a normal sinus rhythm in adults, and it is intended for self-administration during a heart rhythm episode.
The company’s response follows a productive Type A meeting with the FDA, which provided clear guidance on the next steps. The FDA will review the submission and determine the acceptance of the response and the corresponding Prescription Drug User Fee Act date within the next 30 days. If approved, CARDAMYST could become the first self-administered rapid response treatment option for managing PSVT.
Read Announcement- Drug:
- Etripamil
- Announced Date:
- March 28, 2025
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Milestone® Pharmaceuticals Inc. announced the U.S. Food and Drug Administration (FDA) issued a Complete Response Letter (CRL) regarding its New Drug Application (NDA) for CARDAMYST™ (etripamil) nasal spray, a prescription medication in development for the conversion of acute episodes of PSVT to sinus rhythm in adults.
AI Summary
Milestone® Pharmaceuticals Inc. announced that the U.S. Food and Drug Administration (FDA) issued a Complete Response Letter (CRL) for its New Drug Application (NDA) for CARDAMYST™ (etripamil) nasal spray. This medication is being developed as a treatment for converting acute episodes of paroxysmal supraventricular tachycardia (PSVT) into normal sinus rhythm in adults. The FDA did not raise any concerns about the clinical safety or the efficacy of etripamil. However, two key issues related to Chemistry, Manufacturing, and Controls (CMC) were identified. The agency requires additional data on nitrosamine impurities and an inspection at a facility that performs release testing for the drug, as the facility underwent a change in ownership. Milestone remains focused on addressing these issues and aims to collaborate with the FDA for a potential resubmission.
Read Announcement- Drug:
- Etripamil
- Announced Date:
- March 20, 2025
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Milestone® Pharmaceuticals Inc announced that it will present a moderated poster presentation at the American College of Cardiology annual meeting (ACC25), to be held March 29th to 31st, 2025 in Chicago, Illinois.
AI Summary
Milestone® Pharmaceuticals Inc. announced it will present a moderated poster presentation at the American College of Cardiology’s annual meeting (ACC25) in Chicago, Illinois, from March 29-31, 2025. The presentation, titled “Consistency and Predictiveness of Conversion Among Multiple Episodes of Paroxysmal Supraventricular Tachycardia (PSVT) Treated with Etripamil: Outcomes from the NODE-303 trial,” will be led by Dr. James Ip, an associate professor at Weill Cornell Medicine.
The poster details how etripamil, a novel calcium channel blocker nasal spray, has shown promising results by converting multiple PSVT episodes back to normal sinus rhythm. Data presented indicate that successfully converting an early PSVT episode is predictive of success in subsequent episodes. If approved, etripamil could offer patients a convenient self-management option and potentially improve quality of life for those affected by PSVT.
Read Announcement- Drug:
- Etripamil
- Announced Date:
- February 19, 2025
- Indication:
- For Treatment in Paroxysmal Supraventricular Tachycardia
Announcement
Milestone® Pharmaceuticals Inc. announced that it has received Notice of Allowance from the United States Patent and Trademark Office (USPTO) on a new Method of Use patent for etripamil nasal spray (proposed trade name CARDAMYST™), its lead investigational product for the management of paroxysmal supraventricular tachycardia (PSVT).
AI Summary
Milestone® Pharmaceuticals Inc. announced that it has received a Notice of Allowance from the United States Patent and Trademark Office for its new Method of Use patent. This patent application covers the repeat dose regimen for etripamil nasal spray, which is proposed to be marketed under the trade name CARDAMYST™. The regimen, established in the RAPID Phase 3 study for managing paroxysmal supraventricular tachycardia (PSVT), directs patients to take a second dose ten minutes after the first if symptoms persist. With this development, Milestone aims to extend the intellectual property protection of CARDAMYST in the United States until July 2042, adding up to six years of potential protection. This milestone supports the company’s commitment to innovation in cardiology, positioning CARDAMYST as a promising treatment option currently under review with the FDA as part of its New Drug Application.
Read Announcement
ReVeRA-301 FDA Regulatory Events
ReVeRA-301 is a drug developed by Milestone Pharmaceuticals for the following indication: treatment of atrial fibrillation with rapid ventricular rate.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- ReVeRA-301
- Announced Date:
- October 9, 2026
- Indication:
- treatment of atrial fibrillation with rapid ventricular rate
Announcement
Milestone® Pharmaceuticals Inc announced that the first European patient has been enrolled in ReVeRA-301, its ongoing Phase 3 pivotal trial evaluating etripamil nasal spray for the treatment of atrial fibrillation with rapid ventricular rate (AFib-RVR).
Read Announcement
