Milestone, at its founding, sought to create new chemical entities as analogs of known molecular classes with clinically validated mechanisms of action. Our goal remains to preserve the beneficial pharmacology of existing molecules while altering their pharmacokinetic profile with focused medicinal chemistry to produce drugs that are fast-acting and rapidly inactivated in the blood to minimize potential side effects.

As a result, we are developing etripamil, a new chemical entity calcium channel blocker with novel administration in PSVT.

We are currently conducting a comprehensive development program for etripamil designed to explore the following clinical outcomes:

• Administration: Etripamil is designed to be self-administered by patients via a nasal spray device.
• Absorption: Etripamil is designed to be absorbed into the bloodstream in less than 10 minutes through the inner lining of the nose, which has many blood vessels to maximize absorption.
• Action: Etripamil is designed to act rapidly upon the desired organ. Its short duration of action has the potential to avoid or reduce long-term side effects that can occur with chronic drug therapy.

Due to its route of administration, absorption profile, and onset of action, etripamil is being investigated for self-administration outside of the healthcare setting in these indications.

Currently, etripamil is in Phase 2 development for treatment of PSVT in pediatric patients and Phase 3 development for acute treatment of atrial fibrillation with rapid ventricular rate (AFib-RVR) in adults.