Milestone Pharmaceuticals (MIST) FDA Announcement summary

Introduction and purpose

• FDA approved Cardamyst (etripamil) nasal spray as the first self-administered treatment for acute symptomatic episodes of PSVT in adults, marking the first new therapeutic option in over 30 years for more than 2 million Americans with this condition.

• Cardamyst is a novel, short-acting calcium channel blocker designed for rapid, on-demand self-administration, enabling patients to manage episodes outside healthcare settings.

Details of approval or decision

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

• The FDA label met or exceeded expectations, reflecting the strength of the clinical program with no major surprises.

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

Impact on industry and stakeholders

• Over 2 million patients in the US are diagnosed with PSVT, costing the healthcare system at least $5 billion annually; Cardamyst addresses a significant unmet need.

• Cardamyst offers a less invasive, more convenient alternative to current treatments, potentially reducing emergency department visits and hospital admissions.

• No anticipated branded competition and a low barrier to prescribing are expected to drive strong demand and commercial opportunity.

• The product is positioned for broad adoption among cardiologists, electrophysiologists, and select primary care physicians.

• Payers have responded positively to pricing and cost-offset models, supporting favorable formulary placement.