Milestone shares surge 20.74% intraday as CARDAMYST added to Express Scripts national formularies, expanding patient access.

Milestone Pharmaceuticals surged 20.74% intraday after announcing that its FDA-approved nasal spray, CARDAMYST (etripamil), was added to Express Scripts’ commercial national formularies, effective March 27, 2026. The inclusion marks the first contracted formulary acceptance by a major U.S. payor and significantly enhances market access for the treatment of paroxysmal supraventricular tachycardia (PSVT) in commercially insured patients. The company emphasized that this milestone improves affordability and availability, with expectations of broader coverage as discussions with additional insurers continue.