Milestone Pharmaceuticals Inc. (MIST)
First Day Turnover
We are a Phase 3 clinical-stage biopharmaceutical company dedicated to developing and commercializing etripamil for the treatment of cardiovascular indications. Etripamil is a novel, potent and short-acting calcium channel blocker that we designed and are developing as a rapid-onset nasal spray to be administered by the patient to terminate episodes of paroxysmal supraventricular tachycardia, or PSVT, as they occur. PSVT is a rapid heart rate condition that starts and stops without warning, often experienced by patients with symptoms including palpitations, sweating, chest pressure or pain, shortness of breath, sudden onset of fatigue, lightheadedness or dizziness, fainting or anxiety.
Calcium channel blockers have long been approved for the treatment of PSVT as well as other cardiac conditions. For episodes of PSVT, however, calcium channel blockers are administered intravenously under medical supervision, usually in the emergency department. Etripamil's combination of convenient delivery, rapid-onset and short duration of action has the potential to shift the current treatment paradigm away from the burdensome and costly emergency department setting. If approved, we believe that etripamil will be the first self-administered therapy for the rapid termination of episodes of PSVT wherever and whenever they occur.
We completed our Phase 2 clinical trial of etripamil for the treatment of PSVT in the United States and Canada, with results published in the Journal of the American College of Cardiology. Investigators reported an 87% termination rate of PSVT within 15 minutes at the dose selected for Phase 3 versus a 35% termination rate for placebo. We are actively recruiting patients for a Phase 3 clinical trial of etripamil, which may serve as a single pivotal efficacy trial, and we expect top-line data in the first half of 2020. In addition to the efficacy trial, our Phase 3 clinical program for etripamil for PSVT includes two open-label safety studies, one of which we initiated in December 2018, and the other we expect to initiate in the second half of 2019. We are also planning to initiate a Phase 2 clinical trial in the second half of 2019 in atrial fibrillation, another rapid heart rate condition, and expect to subsequently initiate an additional Phase 2 clinical trial in angina to establish proof-of-concept for the broader use of etripamil in 2020.
We believe that PSVT is a large and under-recognized market that we estimate affects approximately two million Americans, and results in over 600,000 healthcare claims in the United States per year, including emergency department visits, hospital admissions and ablations. We believe that, if approved, etripamil could prevent many of these healthcare encounters, saving the patient time and inconvenience, and potentially providing a cost-effective solution for the healthcare system. It is generally believed that patients are born with the anomaly that causes PSVT, and will have life-long episodes periodically and unpredictably. Patients experiencing an episode of PSVT are usually highly symptomatic, with a rapid heart rate, often over 200 beats per minute, causing palpitations, sweating, chest pressure or pain, shortness of breath, sudden onset of fatigue, lightheadedness or dizziness, fainting and anxiety.
We currently have exclusive development and commercialization rights for etripamil for all indications that we may pursue. The composition-of-matter claims for etripamil as a new chemical entity give us a strong intellectual property position with patents issued in the United Stated through 2028, and with patent term extensions possible to 2031. In addition, we have an issued U.S. patent that extends the exclusivity period for the commercial formulation of etripamil to 2036.