A Study Evaluating the Efficacy and Safety of Crovalimab Versus Eculizumab in Participants With Paroxysmal Nocturnal Hemoglobinuria (PNH) Not Previously Treated With Complement Inhibitors

Inclusion Criteria: * Body weight ≥ 40 kg at screening (pediatric participants with body weight \< 40 kg) * Willingness and ability to comply with all study visits and procedures * Documented diagnosis of PNH, confirmed by high sensitivity flow cytometry * LDH level ≥ 2x ULN at screening (as per local assessment) * Vaccination against Neisseria meningitidis serotypes A, C, W, and Y\< 3 years prior to initiation of study treatment; or, if not previously done, vaccination administered no later than one week after the first drug administration * Women of childbearing potential: agreement to remain abstinent or use contraception during the treatment period and for 10.5 months after the final dose of crovalimab or for 3 months after the final dose of eculizumab (or longer if required by the local product label) Exclusion Criteria: * Current or previous treatment with a complement inhibitor * History of allogeneic bone marrow transplantation * History of Neisseria meningitidis infection within 6 months prior to screening and up to first study drug administration * History of myelodysplastic syndrome with Revised International Prognostic Scoring System (IPSS-R) prognostic risk categories of intermediate, high and very high * Pregnant or breastfeeding, or intending to become pregnant during the study, within 10.5 months after the final dose of crovalimab, or 3 months after the final dose of eculizumab (or longer if required by the local product label) * Participation in another in…