A Study Evaluating the Efficacy, Safety, Pharmacokinetics and Pharmacodynamics of Crovalimab in Participants With Paroxysmal Nocturnal Hemoglobinuria (PNH) Not Previously Treated With Complement Inhibition

Inclusion Criteria: * Body weight ≥ 40 kg at screening * Willingness and ability to comply with all study visits and procedures * Documented diagnosis of PNH, confirmed by high sensitivity flow cytometry * LDH Levels ≥ 2x the ULN at screening * Participants who have at least four transfusions during 12 months prior to screening (documented in the medical record) * Presence of one or more of the PNH-related signs or symptoms within 3 months of screening * Vaccination against Neisseria meningitidis serotypes A, C, W, and Y \< 3 years prior to initiation of study treatment (Day 1) * Vaccination against Haemophilius influenzae type B and Streptococcus pneumonia according to national vaccination recommendations * For participants receiving other therapies (e.g., immunosuppressants, corticosteroids): stable dose for ≥ 28 days prior to screening and up to the first drug administration * Adequate hepatic and renal function * Women of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraception during the treatment period and for 46 weeks (approximately 10.5 months) after the final dose of crovalimab * Platelet count ≥30,000 per cubic millimeter (mm\^3) at screening * ANC \> 500/microlitres (μl) at screening 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 f…