The primary objective of this study is to assess the efficacy of a single dose of ravulizumab IV compared with placebo in reducing the risk of the clinical consequences of AKI (MAKE) at 90 days in adult participants with CKD who undergo non-emergent cardiac surgery with CPB.

Inclusion Criteria:

• Participant weighs ≥ 30 kg
• Planned non-emergent sternotomy with CPB procedure for the following surgeries:
• Multi-vessel CABG
• Valve replacement or repair; ascending aorta surgery permitted if combined with aortic valve replacement/repair
• Combined CABG and valve surgery; inclusion of single-vessel CABG when combined with valve replacement/repair is permitted
• Known CKD for at least 90 days (CKD Stage 3A, 3B, or 4)

Exclusion Criteria:

• Emergency or salvage cardiac surgery is expected at screening or randomization, as assessed by the investigator.
• Single-vessel CABG without valve surgery is planned.
• Off-pump surgery is planned (eg, surgery without CPB).
• Recipient of a solid organ or bone marrow transplantation.
• Cardiogenic shock, hemodynamic instability, use of intra-aortic balloon pump, extracorporeal membrane oxygenation, or left ventricular assist device within 72 hours of randomization.
• Active systemic bacterial, viral, or fungal infection within 14 days prior to randomization.
• History of unexplained, recurrent infection.
• Any use of KRT or presence of AKI within 30 days of randomization
• Use of any complement inhibitors, or plasmapheresis or plasma exchange within the year prior to Screening, or planned use during the course of the study.
• Participant is not willing to be vaccinated against N meningitidis or is unwilling to receive prophylactic treatment with appropriate antibiotics , if needed
• History of or unresolved N meningitidis infection.

Alexion has a public commitment to allow requests for access to study data and will be supplying a protocol, CSR, and plain language summaries.