Before participating in this study, information to determine key eligibility criteria was collected as a part of a 14-week Pre-Screening period. The study included a 12-week Screening period and a 52-week (1 year) Treatment period. Eligible participants received crizanlizumab 5 mg/kg by intravenous infusion (IV). Study treatment was received at clinic visits on Week 1 Day 1, Week 3 Day 1, and then on Day 1 of every 4-week cycle. Efficacy assessments included evaluation of priapic and vaso-occlusive (VOC) events. Safety assessments included laboratory tests, electrocardiograms (ECGs), vital signs and physical examinations. Participants had a safety follow-up for up to 15 weeks after the last dose.
