Positive topline data were announced from a phase 3 trial evaluating the efficacy and safety of etripamil, an investigational intranasal calcium channel blocker, in patients who experience an episode of paroxysmal supraventricular tachycardia (PSVT) in an at-home setting.

Etripamil is a self-administered nasal spray designed to be a rapid-response therapy for episodic cardiovascular conditions. The multicenter, randomized, double-blind, placebo-controlled RAPID trial (ClinicalTrials.gov Identifier: NCT03464019) included 706 adults with a history of PSVT. Patients were randomly assigned 1:1 to receive a nasal spray of either etripamil 70mg or placebo without medical monitoring; those who did not experience symptom relief within 10 minutes were allowed to repeat a dose of study drug.

Findings demonstrated that 64.3% of patients treated with etripamil achieved PSVT conversion to sinus rhythm within 30 minutes (primary endpoint) compared with 31.2% of patients who received placebo (hazard ratio, 2.62; 95% CI, 1.66-4.15; P <.001). Compared with placebo, the median time to conversion was reported to be 3 times faster with etripamil. Among etripamil-treated patients, statistically significant reductions in time to conversion were evident early and persisted throughout the study.

The most common treatment emergent adverse events within 24 hours of treatment initiation were related to the nasal administration site, and were reported as mild (68%) to moderate (31%). No serious adverse events were reported in the etripamil arm.

Additionally, pooled data from the NODE-301 and RAPID trials showed that treatment with etripamil was associated with statistically significant reductions in the use of additional medical interventions and visits to the emergency department.

“We believe that etripamil, if approved, has the potential to empower patients to take control of their condition as well as provide value to the healthcare system, in part by reducing visits to the Emergency Department,” said Joseph Oliveto, President and Chief Executive Officer of Milestone Pharmaceuticals. “We look forward to working with the US Food and Drug Administration (FDA) to make available what we believe is the first of its kind, self-administered therapy.”


Milestone Pharmaceuticals announces positive results from Phase 3 RAPID clinical trial of etripamil nasal spray in patients with paroxysmal supraventricular tachycardia. News release. Milestone Pharmaceuticals, Inc. Accessed October 17, 2022. https://www.prnewswire.com/news-releases/milestone-pharmaceuticals-announces-positive-results-from-phase-3-rapid-clinical-trial-of-etripamil-nasal-spray-in-patients-with-paroxysmal-supraventricular-tachycardia-301650366.html