Tuan Vu, MD, Professor, Department of Neurology at the University of South Florida, discusses positive results of cemdisiran in patients with generalized myasthenia gravis (gMG).
MG is a chronic autoimmune neuromuscular disease characterized by weakness of the skeletal muscles. Common symptoms include weakness of the muscles that control the eye and eyelid, facial expressions, chewing, talking, and swallowing. The condition results from a defect in the transmission of nerve impulses to muscles due to the presence of antibodies against the acetylcholine receptor. The exact reason this occurs is not known.
Cemdisiran is a RNA interference (RNAi) therapy designed to silence the C5 gene, thereby dampening the complement system that appears to be involved in the pathophysiology of gMG.
Positive results from the phase 3 NIMBLE clinical trial (NCT05070858) of cemdisiran in adults with gMG were recently presented at the 2026 American Academy of Neurology (AAN) Annual Meeting and published in The Lancet. Cemdisiran is a novel siRNA therapeutic designed to durably reduce circulating levels of complement factor 5 (C5). The trial enrolled a total of 123 patients, with 59 in the placebo group and 64 patients treated with subcutaneous cemdisiran every 12 weeks.
Compared to placebo, at week 24, a 4.5-point improvement from baseline on the Myasthenia Gravis Activities of Daily Living (MG-ADL) total score was observed. Notably, 76.6% of cemdisiran-treated patients had a 3-point or greater improvement, versus 44.1% for placebo. Clinically meaningful improvements in MG-ADL total score occurred within 2 weeks in cemdisiran-treated patients.
Additionally, a 4.2-point improvement from baseline in Quantitative Myasthenia Gravis (QMG) total score was observed in the cemdisiran group, versus a 1.5-point improvement in the placebo group. Notably, 48.4% of cemdisiran patients had a 5-point or greater improvement, compared to 19% for placebo. Improvements in QMG total scores occurred within 2 weeks in cemdisiran-treated patients.
The most common AEs were: worsening of MG, upper respiratory tract infection, urinary tract infection, nasopharyngitis, headache, rash, and diarrhea. One or more treatment-emergent adverse events occurred in 69.2% of patients receiving cemdisiran and 77.1% receiving placebo. Most AEs were mild-to-moderate in severity.
For more information, click here.
To learn more about MG and other rare autoimmune conditions, visit https://checkrare.com/diseases/autoimmune-autoinflammatory-disorders/