The FDA has accepted cemdisiran for priority review as a potential first-of-its-kind siRNA therapy for generalized myasthenia gravis (gMG). If approved, it would be the only gMG treatment given subcutaneously just four times a year. Phase 3 trial data published in The Lancet showed rapid, meaningful improvements in daily functioning within just two weeks of treatment.
The FDA has accepted Regeneron's cemdisiran for priority review as a treatment for generalized myasthenia gravis (gMG), a chronic autoimmune disorder that disrupts nerve-muscle communication and can impair everyday functions like eating, talking, and breathing. If approved, cemdisiran would be the first small interfering RNA (siRNA) therapy for gMG — and the only option requiring just four subcutaneous doses per year, a significant step down in treatment burden compared to current options that range from daily injections to bimonthly IV infusions.
The European Medicines Agency has also accepted the drug for review, with a decision expected in the second half of 2027. The FDA's target action date is November.
Key Takeaways:
Why it matters: With roughly 85,000 Americans living with gMG and many still struggling to achieve durable disease control, cemdisiran's novel mechanism and convenient dosing schedule could meaningfully improve quality of life for patients who haven't found lasting relief with existing therapies.
