ALXN1210 Versus Eculizumab in Adult Participants With Paroxysmal Nocturnal Hemoglobinuria (PNH) Currently Treated With Eculizumab

The study consisted of a 4-week Screening Period and a 26-week Randomized Treatment Period
(Primary Evaluation Period). After completion of the Primary Evaluation Period, all
participants had the opportunity to enter the Extension Period, wherein participants will
receive ravulizumab for up to 2 years.

This study is ongoing. The data presented is up to the Primary Completion date of the study
and is for the Primary Evaluation Period. The results for the Extension Period will be
reported after study completion.

Inclusion Criteria:

1. Male or female ≥18 years of age.

2. Treated with eculizumab for PNH for at least 6 months prior to Day 1.

3. Lactate dehydrogenase level ≤1.5 times the upper limit of normal (ULN) at screening.

4. PNH diagnosis confirmed by documented by high-sensitivity flow cytometry.

5. Documented meningococcal vaccination not more than 3 years prior to, or at the time
of, initiating study treatment.

6. Female participants of childbearing potential must use highly effective contraception
starting at screening and continuing until at least 8 months after the last dose of
ravulizumab.

7. Willing and able to give written informed consent and comply with study visit
schedule.

Exclusion Criteria:

1. History of bone marrow transplantation.

2. Body weight <40 kilograms at screening.

3. History of or ongoing major cardiac, pulmonary, renal, endocrine, or hepatic disease
that, in the opinion of the investigator or sponsor, would preclude participation.

4. Unstable medical conditions (for example, myocardial ischemia, active gastrointestinal
bleeding, severe congestive heart failure, anticipated need for major surgery within 6
months of randomization, or coexisting chronic anemia unrelated to PNH).

5. Female participants who are pregnant, breastfeeding, or who have a positive pregnancy
test at screening or Day 1.

6. Participation in another interventional clinical study or use of any experimental
therapy within 30 days before initiation of study treatment on Day 1 in this study or
within 5 half-lives of that investigational product, whichever is greater.