An Efficacy and Safety Study of Ravulizumab in ALS Participants

Open to people ages 18 years and up

1. A diagnosis of sporadic or familial ALS, defined by the El Escorial criteria (possible, laboratory-supported probable, probable, or definite ALS).
2. ALS onset ≤ 36 months from Screening.
3. Documented meningococcal vaccination not more than 3 years prior to, or at the time of, initiating study treatment.
4. Upright slow vital capacity ≥ 65% predicted at Screening.
5. If on riluzole, participant must be on a stable dose for 30 days; if on edaravone, participant must be on a stable dose for 60 days (2 cycles).
6. Body weight ≥ 40 kilograms at Screening.
7. Contraceptive use by men or women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.

1. History of Neisseria meningitidis infection.
2. Human immunodeficiency virus (HIV) infection (evidenced by HIV 1 or HIV 2 antibody titer).
3. Dependence on invasive or non-invasive mechanical ventilation.
4. Previously or currently treated with a complement inhibitor.
5. Exposure to an investigational drug or device within 30 days of Screening or 5 half lives of the study drug, whichever is greater.