A Study to Evaluate the Efficacy and Safety of Eculizumab in Guillain-Barré Syndrome

Inclusion Criteria:

• Participants who meet the GBS criteria.
• Participants who were able to run prior to onset of GBS symptoms.
• Participants with onset of weakness due to GBS < 2 weeks before screening.
• Participants unable to walk unaided for ≥ 5 meters (progressively deteriorating FG3 orFG4 to FG5).
• Participants who are already on IVIg or deemed eligible for and who will start IVIg.
• Participants who can start their first dose of study drug before the end of the IVIgtreatment period.

Exclusion Criteria:

• Participants who have previously received or are currently receiving treatment withcomplement modulators.
• Participants who have been administered another investigational product within 30 daysor 5 half-lives (whichever is longer) prior to providing consent or are currentlyparticipating in another interventional study.
• Participants who have received rituximab within 12 weeks prior to screening.
• Participants who are being considered for or are already on plasmapheresis.
• Participants who have received immunosuppressive treatment during the 4 weeks prior toproviding consent.