Study of Ravulizumab in Pediatric Participants With HSCT-TMA

Inclusion Criteria:

1. ≥ 28 days of age up to < 18 years of age at the time of signing the informed consent.
2. Received HSCT within the past 12 months.
3. Diagnosis of TMA that persists for at least 72 hours despite initial management.
4. A TMA diagnosis based on meeting the select criteria during the Screening Period and/or <=14 days prior to the Screening Period.
5. Body weight ≥ 5 kilograms at Screening or ≤7 days prior to the start of the Screening Period (date of consent).
6. Female participants of childbearing potential and male participants with female partners of childbearing potential must use highly effective contraception.
7. Participants must be vaccinated against meningococcal infections if clinically feasible. Participants who cannot receive meningococcal vaccine should receive antibiotic prophylaxis.
8. Participants or their legally authorized representative must be capable of giving signed informed consent or assent

Exclusion Criteria:

1. Thrombotic thrombocytopenic purpura (TTP) evidenced by ADAMTS13 deficiency.
2. Shiga toxin producing Escherichia coli infection.
3. Positive direct Coombs test
4. Clinical diagnosis of disseminated intravascular coagulation (DIC)
5. Known bone marrow/graft failure.
6. Diagnosis of veno-occlusive disease (VOD), regardless of severity.
7. Human immunodeficiency virus (HIV) infection
8. Unresolved meningococcal disease.
9. Presence or suspicion of sepsis (treated or untreated).
10. Pregnancy or breastfeeding.
11. Respiratory failure requiring mechanical ventilation
12. Previously or currently treated with a complement inhibitor
13. Participation in an interventional treatment study of any therapy for TMA