A Phase IIa Study to Assess the Safety, Efficacy, and Pharmacokinetics of Subcutaneously Administered Pegcetacoplan (APL-2) in Subjects With PNH

Inclusion Criteria: * At least 18 years old (inclusive) * Diagnosed with PNH (white blood cell (WBC) clone \>10%) * Lactose dehydrogenase (LD) ≥2 times the upper limit of normal * Screening Ferritin ≥ normal and Total Iron Binding Capacity (TIBC) \< LLN based on central lab reference ranges. If a subject is receiving iron supplements at screening, the investigator must ensure that his/her dose has been stable for 8 weeks prior to enrolment and must be maintained throughout the study * Last transfusion within 12 months prior to screening * Platelet count of \>30,000/mm3 at the screening visit * Absolute neutrophil count \>500/ mm3 at the screening visit * Women of child-bearing potential (WOCBP) must have a negative pregnancy test at screening and must agree to use protocol defined methods of contraception for the duration of the study * Males must agree to use protocol defined methods of contraception and agree to refrain from donating sperm for the duration of the study * Vaccination against Neisseria meningitides types A, C, W, Y and B, Streptococcus pneumoniae and Haemophilus influenzae Type B (Hib) either within 2 years prior to Day 1 dosing, or within 14 days after starting treatment with pegcetacoplan. Unless documented evidence exists that subjects are non-responders to vaccination as evidenced by titers or display titer levels within acceptable local limits * Willing and able to give informed consent Exclusion Criteria: * Prior eculizumab (Soliris®) treatment * Active bacterial infection * Hereditary complement deficiency * History of bone marrow transplantation * Concurrent severe aplastic anemia (SAA), defined as currently receiving immunosuppressive therapy for SAA including but not limited to cyclosporin A, tacrolimus, mycophenolate mofetil or anti-thymocyte globulin * Participation in any other investigational drug trial or exposure to another investigational agent, device or procedure within 30 days * Evidence of QTcF prolongation defined as \>450 ms for males and \>470 ms for females at screening * Breast-feeding women * History of meningococcal disease