2026 American Academy of Neurology Autoimmune Abstract Website

Objective:

To update U.S. exposure-adjusted Nm infection and mortality rates in eculizumab- or ravulizumab-treated patients with gMG and NMOSD using post-marketing pharmacovigilance (Nm case counts) and commercial data (exposure).

Background:

Eculizumab and ravulizumab are approved therapies for generalized myasthenia gravis (gMG) and neuromyelitis optica spectrum disorder (NMOSD). Vaccinations and antibiotic prophylaxis are used to reduce the risk of Neisseria meningitidis (Nm) infection associated with these treatments.

Design/Methods:

The Alexion safety database was searched for eculizumab (data cutoff: October 2025) and ravulizumab (December 2025) across approved indications (i.e., gMG, NMOSD, paroxysmal nocturnal hemoglobinuria, atypical hemolytic uremic syndrome) using the MedDRA high-level term “Neisseria infection”. Only U.S., Nm-associated cases were included. Cumulative reporting rates were calculated per 100 patient-years (PY) of exposure.

Results:

By 2025, cumulative U.S. exposures reached 34,713 PY for eculizumab and 21,348 PY for ravulizumab. Cumulative U.S. Nm infection and mortality rates remained stable across indications (eculizumab: 0.14 and 0.01; ravulizumab: 0.07 and 0.01, respectively). In eculizumab‑treated patients, Nm infection rates were 0.05 in gMG (9,545 PY) and 0.12 in NMOSD (2,464 PY). In ravulizumab‑treated patients, corresponding rates were 0.03 (gMG; 6,522 PY) and 0.13 (NMOSD; 792 PY). No Nm‑associated fatalities occurred among U.S. neurology patients despite nearly 20,000 PY of combined exposure.

Conclusions:

Nm infection rates remained low and stable despite 2–3-fold increases in U.S. complement inhibitor exposure from initial gMG approvals through 2025, without Nm-related fatalities in neurology indications. These results support the effectiveness of U.S. risk mitigation strategies for the safe use of eculizumab and ravulizumab.