Regeneron Pharmaceuticals has announced that both the US FDA and the European Medicines Agency (EMA) have accepted the regulatory applications for cemdisiran to treat adult patients with generalised myasthenia gravis (gMG) who are anti-acetylcholine receptor (AChR) antibody-positive.
The submissions are supported by data from the phase 3 NIMBLE trial evaluating cemdisiran, dosed subcutaneously every 12 weeks, in adults with symptomatic gMG who may be receiving standard of care immunosuppressants based on the investigator’s discretion.
Full data from NIMBLE, which is one of the largest global, interventional gMG trials conducted to date, were simultaneously published in The Lancet and presented at the American Academy of Neurology (AAN) Annual Meeting in April 2026. A regulatory filing in Japan is also planned for early 2027.
MG is a rare and chronic autoimmune disease where abnormal anti-AChR antibodies activate the complement system including C5, disrupting communication between nerves and muscles that results in debilitating and potentially life-threatening muscle weakness. Worldwide, an estimated 150 to 200 out of every million people have MG. In the US, the disease impacts approximately 85,000 people.
Initial manifestations are usually ocular, but approximately 85% of MG patients experience progression to additional disease manifestations, which is then categorised as generalised MG. For these patients, the disease affects muscles throughout the body, resulting in extreme fatigue and difficulties with facial expression, speech, swallowing and mobility.
For patients living with gMG, many continue to experience challenges with disease management including treatments that only address symptoms, long-term burden of immunosuppressants, lack of responsiveness as well as waning effectiveness, which can all affect their quality of life.
The FDA will review the New Drug Application (NDA) under Priority Review with a target action date in November 2026, following use of a Priority Review Voucher. A decision from the European Commission is anticipated in the second half of 2027.