Dose-Escalation Study of ALXN1210 IV in Participants With Paroxysmal Nocturnal Hemoglobinuria (PNH)

Inclusion Criteria: 1. Male or female ≥18 years of age 2. PNH diagnosis confirmed by documented high-sensitivity flow cytometry 3. Documented meningococcal vaccination not more than 3 years prior to dosing 4. Female participants of childbearing potential used highly effective contraception starting at screening and continuing until at least 24-weeks after the last dose of ALXN1210 5. Willing and able to give written informed consent and comply with the study visit schedule Exclusion Criteria: 1. Treatment with a complement inhibitor at any time 2. Females who were pregnant, breastfeeding or who had a positive pregnancy test at screening or Day 1 3. Participation in an interventional clinical study within 30 days before initiation of dosing on Day 1, or use of any experimental therapy within 30 days prior to dosing on Day 1, or within 5 half-lives of the product, whichever is greater 4. History of allergy to excipients of ALXN1210 or known allergy to Chinese hamster ovary cell proteins 5. Inability to comply with study requirements 6. History of any clinically significant cardiac, hepatic, immunologic, pulmonary, or rheumatoid disease that, in the Investigator's judgment, would preclude participation 7. Other unspecified reasons that, in the opinion of the Investigator or Sponsor, made the participant unsuitable for enrollment