Patient description: The patient is a 23-year-old man who came to the hospital with high blood pressure (175/95 mmHg) and signs of septicemia. He developed respiratory failure requiring mechanical ventilation and renal failure requiring hemodialysis. His blood smear showed microangiopathic hemolytic anemia and thrombocytopenia. His blood tests revealed elevated lactate dehydrogenase and reduced human complement C3 levels with a normal coagulation profile. He was diagnosed with atypical hemolytic uremic syndrome. He was treated with plasma exchange and corticosteroids. He has been previously vaccinated with meningococcal group ACWY conjugate vaccine and meningococcal group B vaccine. The genetic survey revealed ADAMTS13 >10%.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Paroxysmal Hemoglobinuria, Nocturnal The study population will comprise individuals who have transfusion-dependent hemolytic PNH Each patient must meet the following to be enrolled in this study: 1. Individuals at least 18 years of age 2. Patients with a diagnosis of PNH greater than 6 months 3. Presence of a GPI deficient red blood cell clone (type III cells) by flow cytometry of greater than or equal to 10% 4. Patients must have: at least one transfusion in the past two years for anemia or anemia-related symptoms -or personal beliefs that preclude the use of transfusion, with severe hemolytic PNH 5. Documented LDH level greater than or equal to 1.5 x upper limit of normal (ULN) within 12 weeks of Visit 1 or during the Screening Period 6. Patient must be willing and able to give written informed consent. 7. Patients must avoid conception during the trial using a method that is most appropriate for their physical state and culture Subjects must have a Visa allowing stay in United States for the duration of the study (up to 3 years) Subjects must provide documentation of residence during stay in the United States The subject must be willing to keep all visits and not travel outside of the country while being treated under the protocol The subject must understand that the drug may not be made commercially available in their country Once the protocol and extension study is complete, the subject must come off study medication and it will not be made available to them if they return to their country  -Any patient meeting any of the following will be excluded from the study: 1. Platelet count of less than 30,000/mm3 2. Absolute Neutrophil count less than or equal to 500/uL 3. Presence or suspicion of active bacterial infection, in the opinion of the Investigator, at Visit 2 or recurrent bacterial infections 4. Known or suspected hereditary complement deficiency 5. History of bone marrow transplantation 6. Participation in any other investigational drug trial or exposure to other investigational agent, device, or procedure within 30 days prior to screening 7. Pregnant, breast-feeding, or intending to conceive during the course of the study,including the Safety Follow-up Visits 8 .History of meningococcal disease 9. Patients who are not vaccinated against N. meningitidis at least 14 days prior to Visit 2 10. Any condition that, in the opinion of the Investigator, could increase the patient's risk by participating in the study or confound the outcome of the study