Long-Term Safety, Tolerability and Efficacy of OMS906 in Paroxysmal Nocturnal Hemoglobinuria

Inclusion Criteria: 1. Have completed the last dosing visit of the prior OMS906 PNH study. 2. Female patients of child bearing potential must have a negative result from a highly sensitive urine pregnancy test prior to each dose of OMS906. 3. Females must use highly effective birth control to prevent pregnancy during the clinical trial and for 20 weeks following their last dose of study drug. 4. Males must use highly effective birth control with a female partner to prevent pregnancy during the clinical trial and for 20 weeks after last dose of study drug. 5. Have current vaccination status for Neisseria meningitidis, Streptococcus pneumonia and Hemophilus influenza and agree to maintain vaccination throughout the study. 6. Have provided informed consent Exclusion Criteria: 1. Platelet count \<30,000/µL or absolute neutrophil count \<500 cells/µL at the start of the Evaluation Period. 2. Elevation of liver function tests, defined as total bilirubin \> 2 x ULN, direct bilirubin \> 1.5 x ULN, and elevated transaminases (alanine or aspartate aminotransferase), \> 2 X ULN unless due to PNH-related hemolysis. 3. History of any severe hypersensitivity reactions to other monoclonal antibodies or excipients included in the OMS906 preparation. 4. Patients with unresolved serious infections caused by encapsulated bacteria including H. influenzae, S. pneumoniae and N. meningitidis. 5. Pregnant, planning to become pregnant, or nursing female patients. 6. History of any significant medical, neurologic, or psychiatric disorder that in the opinion of the investigator would make the patient unsuitable for participation in the long-term extension. 7. Unable or unwilling to comply with the requirements of the study.