Study of Danicopan in Participants With Paroxysmal Nocturnal Hemoglobinuria With Inadequate Response to Eculizumab

Key Inclusion Criteria: * Diagnosed with PNH * Have received at least one red blood cell transfusion within last 12 weeks * Anemia with adequate reticulocytosis * Must be on a stable regimen of eculizumab * Platelet count ≥ 40,000/microliter without the need for platelet transfusions * Documentation of vaccination for Neisseria meningitidis, Haemophilus influenza, and Streptococcus pneumoniae or willingness to receive vaccinations based on local guidelines * Willingness to receive antibiotic prophylaxis * Female participants must use highly effective birth control to prevent pregnancy during the clinical trial and for 30 days after their last dose of study drug * Male participants must use a highly effective birth control with a female partner to prevent pregnancy during the clinical trial and for 90 days after the last dose of study drug Key Exclusion Criteria: * Current evidence of bone marrow failure or aplastic anemia requiring treatment * History of a major organ transplant or hematopoietic stem cell/marrow transplant * Received another investigational agent within 30 days or 5 half-lives of the investigational agent prior to study entry, whichever is greater * Documented C5 complement protein mutations * Known or suspected complement deficiency * Contraindication to any of the required vaccinations * Active bacterial infection or clinically significant active viral infection, a body temperature \>38°C, or other evidence of infection * History of meningococcal infection, or a first-degree relative or household contact with a history of meningococcal infection * History of hypersensitivity reactions to commonly used antibacterial agents Note: Additional inclusion/exclusion criteria may apply, per protocol.