Etripamil Phase III Clinical Trials Are Successful

Milestone Pharmaceuticals recently announced positive test results from a phase III clinical trial of etripamil, a calcium channel blocker to treat paroxysmal supraventricular tachycardia (PSVT). PSVT affects approximately two million people in the United States and can cause symptoms such as palpitations, sweating, shortness of breath, and chest pain. The currently available treatments for PSVT are intravenous adenosine, beta-blockers, and calcium channel blockers. Unlike current therapies, etripamil can be administered as a nasal spray by the patient.

"PSVT is an unpredictable, disruptive burden on patients, with current interventions restricted to the costly and inconvenient acute care setting," said Bruce Stambler, MD, FHRS, Director of Cardiac Arrhythmia Research and Education, Piedmont Heart Institute, Atlanta, GA, in the press release.

"I am highly encouraged by the findings from the RAPID trial, which demonstrate that patients who administered etripamil converted to normal sinus rhythm significantly more often than placebo patients without experiencing serious adverse events, and independent of medical supervision. These data further support the potential for etripamil to deliver a clinically meaningful benefit to patients and an important and valuable tool for their physicians."

The clinical trial is called RAPID, a multicenter, randomized, double-blind study with 706 participants in North America and Europe. Approximately half of the patients received the etripamil, and the other half received a placebo. The investigation resulted in patients taking etripamil having statistically better time to PSVT conversions. On average, the conversions were three times faster than patients in the placebo group.

In addition, there were severe adverse effects experienced by patients. Mild side effects were experienced by 68% of patients, and moderate side effects were experienced by 31%.

According to the press release, “the company believes results from the RAPID trial together with the data from the already completed NODE-301 trial could fulfill the efficacy requirement for a New Drug Application (NDA) submission for etripamil in patients with PSVT. The Company continues to enroll patients in the open-label NODE-303 safety trial and plans to submit an NDA application in mid-2023 pending agency feedback.”

As these clinical trials progress, providers will monitor the FDA status of this drug. If successful, this drug may provide an additional, less invasive tool for treating PSVT.