Milestone Pharmaceuticals (MIST) FDA Announcement summary

Introduction and purpose

• FDA approved Cardamyst (etripamil) nasal spray as the first new, self-administered treatment for PSVT in over 30 years, addressing a significant unmet need for over 2 million Americans.

• The product is a novel, short-acting calcium channel blocker designed for rapid, on-demand self-administration outside healthcare settings.

Details of approval or decision

• Cardamyst is indicated for acute treatment of PSVT in adults, approved for intranasal use only, with each device delivering a 70 mg dose via two sprays.

• The FDA label met or exceeded expectations, with a clean safety and tolerability profile and no major surprises.

• Patent protection extends until 2042, supporting long-term market exclusivity.

Impact on industry and stakeholders

• Cardamyst is expected to become the new standard of care, reducing emergency department visits and improving patient quality of life.

• Over 2 million patients diagnosed with PSVT in the US, costing the healthcare system at least $5 billion annually.

• No anticipated branded competition and a low barrier to prescribing are expected to drive strong demand and minimal rebate pressure.

• The launch targets 10,000 key healthcare providers, primarily cardiologists and electrophysiologists, with an initial sales force of 60 representatives.

• Expected to be available in retail pharmacies in Q1 2026.