FDA and EMA accept regulatory submissions for cemdisiran in generalised myasthenia gravis

Regeneron Pharmaceuticals has recently confirmed that both the US FDA and the European Medicines Agency have accepted regulatory applications for cemdisiran targeting adult patients with generalised myasthenia gravis who test positive for anti-acetylcholine receptor antibodies. A Priority Review Voucher was used in connection with the New Drug Application, with the FDA aiming for a decision by November 2026. The European Commission is expected to reach its own determination in the latter half of 2027, with a Japanese regulatory filing planned for early 2027.

Findings from the Phase 3 NIMBLE trial provide the foundation for both submissions. The study evaluated cemdisiran given subcutaneously every 12 weeks in adults with symptomatic generalised myasthenia gravis, with standard of care immunosuppressants permitted at the clinician’s discretion. Representing one of the largest interventional generalised myasthenia gravis trials ever conducted on a global scale, NIMBLE’s complete dataset was published in The Lancet and presented at the American Academy of Neurology Annual Meeting in April 2026 simultaneously.

Myasthenia gravis is a rare, persistent autoimmune condition in which irregular anti-acetylcholine receptor antibodies trigger complement system activation, including C5, interrupting the signals that pass between nerves and muscles and causing weakness that can be both severely disabling and life-threatening. Globally, between 150 and 200 individuals per million are estimated to carry the diagnosis, with around 85,000 people affected in the US. Symptoms typically emerge first in the eyes, yet close to 85% of patients go on to experience involvement of further muscle groups, at which stage the condition is reclassified as generalised myasthenia gravis. Those living with the generalised form face profound fatigue alongside impairment in facial expression, speech, swallowing, and physical mobility. A considerable proportion of patients continue to encounter significant difficulties in managing their condition, navigating therapies that address only the surface of the disease, the long-term weight of immunosuppressant regimens, inadequate or diminishing responses to treatment, and a cumulative erosion of their quality of life.

The safety, efficacy, and suitability of cemdisiran for the treatment of generalised myasthenia gravis remain under investigation and have not yet been fully assessed or approved by any regulatory body.

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Related Topics and Keywords

EMA, FDA, generalised myasthenia gravis