Everest Medicines’ Licensing Partner Milestone Pharmaceuticals Announces Data Presented at ESC Congress 2026 on the Impact of Paroxysmal Supraventricular Tachycardia (PSVT) on Patients’ Daily Lives and Quality of Life Between Episodes

Shanghai, China - September 18, 2026 - Everest Medicines (HKEX 1952.HK, "Everest", or the "Company") announced findings from a longitudinal study describing how paroxysmal supraventricular tachycardia (PSVT) affects patients’ daily lives and quality of life in the periods between episodes. The findings are being presented in a moderated ePoster session titled “The Impact of PSVT on Patients’ Daily Life and QoL in Between Episodes” at the European Society of Cardiology (ESC) Congress 2026 on August 30, 2026, 15:15-16:00 CET, Station 6, Research Gateway, Hall A1. The news was previously released by Milestone Pharmaceuticals Inc . (Nasdaq: MIST), a biopharmaceutical company focused on the development and commercialization of innovative cardiovascular medicines. Everest Medicines has an exclusive license with Milestone to develop and commercialize etripamil nasal spray in Greater China (including Mainland China, Hong Kong, Macao and Taiwan). 

China’s National Medical Products Administration (NMPA) has approved CARDAMYST^® (etripamil) for the conversion of acute symptomatic episodes of paroxysmal supraventricular tachycardia (PSVT) to sinus rhythm in adults.

PSVT is a common heart rhythm disorder in which the heart suddenly beats very fast affecting an estimated two million people in the United States. The acute symptoms of a PSVT episode are well recognized. However, the impact of living with the condition between episodes has not been well established. This study assessed patient-reported outcomes over nearly a year, capturing how PSVT shaped participants’ activities, emotions, and quality of life outside of a healthcare setting. The results show that many people living with PSVT change their behavior, avoid everyday activities, and carry anxiety with them even when they are not having an episode.

Key Findings

● Approximately two in three patients adjusted their lifestyle between episodes to avoid stress, and nearly 40% reduced their activity or exercise routine because of PSVT.

● 73% of patients reported daytime activity interruption between PSVT episodes.
● Automobile driving (53%) and travel (43%) were the everyday activities for which avoidance between PSVT episodes was most frequently rated as bothersome or extremely bothersome (score of 6 or 7 on a 7-point scale).
● Anxiety persisted between PSVT episodes. Patients reported an average anxiety level of 3.1 on a 7-point scale; 26% of patients reported feeling extremely anxious at some point during the study, and 16% reported the maximum anxiety score at least once.
● Side effects of medications taken chronically (e.g., daily) for PSVT were frequently reported as burdens. Fatigue and weakness were each rated as bothersome or extremely bothersome (6 or 7 on a 7-point scale) by 65% of patients.
● Sleep (30%) and capacity for work (22%) were the most commonly reported areas of lifestyle dissatisfaction (score of 1 or 2 on a 5-point scale).

Conclusions

● PSVT imposes a substantial quality-of-life burden between episodes, affecting anxiety, daily activities, sleep, and work. Medication side effects and activity avoidance further contribute to this burden, underscoring that the impact of PSVT extends beyond acute symptomatic episodes and highlighting an unmet treatment need.

● The authors call for future research to evaluate the quality-of-life impact of at-home, self-administered treatments to terminate PSVT episodes.

The prospective, longitudinal, web-based survey study enrolled 247 adults in the United States and United Kingdom with a self-reported diagnosis of PSVT and no history of catheter ablation at enrollment. Participants completed a baseline survey in February 2019, weekly tracking surveys through December 2019, and a closing survey. During weeks without a PSVT episode, participants completed quality-of-life assessments, including the World Health Organization Quality of Life–Brief Version (WHOQOL-BREF), and answered questions about lifestyle changes, avoidance behaviors, emotional symptoms, and anxiety. Participants had a mean age of 52 years, 72% were female, and the population carried a substantial comorbidity burden. The study was funded by Milestone Pharmaceuticals.

“Better understanding the impact of PSVT on the patients’ daily lives - including between acute events - is important as we consider the management and treatment options which can more fully address the needs of people living with this condition,” said David Bharucha, M.D., PhD, FACC , Chief Medical Officer of Milestone Pharmaceuticals.


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 healthcare providers are dissatisfied with the lack of effective treatment options, with patients often electing to pursue prolonged, burdensome, and costly trips to the emergency department or even undergo invasive cardiac ablation procedures.

About Everest Medicines
Everest Medicines is a biopharmaceutical company focused on discovering, developing, manufacturing and commercializing innovative pharmaceutical products that address critical unmet medical needs for patients in global markets. The management Team of Everest Medicines has deep expertise and an extensive track record both in China and with leading global pharmaceutical companies.
The Company’s therapeutic areas of focus include autoimmune, ophthalmology, critical care, and CKM (cardiovascular, kidney, and metabolic) diseases. Everest Medicines has developed a fully integrated commercialization platform that combines omnichannel commercial capabilities with end-to-end product lifecycle management. Leveraging its proprietary mRNA platform, the Company is advancing its existing pipeline, including mRNA in vivo CAR-T and mRNA cancer vaccines, while selectively expanding into additional high-value therapeutic areas with blockbuster potential, and accelerating its global expansion. For more information, please visit the Company's website: www.everestmedicines.com.

About Milestone Pharmaceuticals
Milestone Pharmaceuticals Inc . (Nasdaq: MIST) is an emerging commercial-stage biopharmaceutical company advancing innovative cardiovascular medicines to Benefit people living with certain heart conditions. Milestone’s lead product is CARDAMYST® (etripamil) nasal spray, a novel calcium channel blocker, which is FDA-approved for the conversion of acute symptomatic episodes of paroxysmal supraventricular tachycardia (PSVT) to sinus rhythm in adults. Etripamil is also in Phase 3 development for the control of symptomatic episodic attacks associated with AFib-RVR. https://milestonepharma.com/

Forward-Looking Statements
This news release may make statements that constitute forward-looking statements, including descriptions regarding the intent, belief or current expectations of the Company or its officers with respect to the business operations and financial condition of the Company, which can be identified by terminology such as “will,” “expects,” “anticipates,” “future,” “intends,” “plans,” “believes,” “estimates,” “confident” and similar statements. Such forward-looking statements are not guarantees of future performance and involve risks and uncertainties, or other factors, some of which are beyond the control of the Company and are unforeseeable. Therefore, the actual results may differ from those in the forward-looking statements as a result of various factors and assumptions, such as future changes and developments in our business, competitive environment, political, economic, legal and social conditions. The Company or any of its affiliates, directors, officers, advisors or representatives has no obligation and does not undertake to revise forward-looking statements to reflect new information, future events or circumstances after the date of this news release, except as required by law.