Ravulizumab in Adult Participants With Paroxysmal Nocturnal Hemoglobinuria Currently Treated With High-Dose Eculizumab

Participants must have been prescribed and be receiving a stable dose of eculizumab 1200 milligrams (mg) every 2 weeks (q2w) for at least 3 months prior to the Screening Period. During the Screening Period, participants will continue to receive eculizumab 1200 mg q2w.

During the Treatment Period, participants will receive a loading dose of ravulizumab on Day 1, followed by maintenance doses on Day 15 and every 8 weeks, administered by intravenous infusion. Ravulizumab loading and maintenance doses will be based on participants' body weight per approved dose regimen.