Study to Evaluate the Efficacy of ASP1128 (MA-0217) in Subjects at Risk for Acute Kidney Injury (AKI) Following Coronary Artery Bypass Graft (CABG) and/or Valve Surgery

Inclusion Criteria

• Subject agrees not to participate in another interventional study after signing the informed consent form and until the end of study (EoS) visit has been completed.
• Subject is ≥ 35 years of age at the time of screening (visit 1).
• Subject undergoing non-emergent open chest cardiovascular surgery with the use of cardiopulmonary bypass pump (CPB) (i.e., coronary artery bypass graft (CABG) and/or valve surgery [including aortic root and ascending aorta surgery without circulatory arrest]) within 4 weeks of screening (visit 1).
• Subject is at risk of developing acute kidney injury (AKI) following cardiovascular surgery, i.e., has 1 or more of the following AKI risk factors:
• Age at screening of ≥ 70 years
• Documented history of eGFR 2 times the upper limit of normal (ULN) or bilirubin increased to > 1.5 times the ULN.
• eGFR < 30 mL/min per 1.73 m^2 as per CKD-EPI equation.
• Subject has use of left ventricular assist device, intra-aortic balloon pump or other cardiac devices, or catecholamines within 7 days prior to screening.
• Subject has surgery scheduled to be performed without CPB (i.e., "Off-Pump" surgery).
• Subject has surgery scheduled to be performed under conditions of circulatory arrest, including planned deep hypothermic circulatory arrest.
• Subject has surgery scheduled for aortic dissection.
• Subject has surgery for a condition that is immediately life-threatening.
• Subject has surgery scheduled to correct major congenital heart defect.
• Subject has current or previous malignant disease. Subjects with a history of cancer are considered eligible if the subject has undergone therapy and the subject has been considered disease free or progression free for at least 5 years. Subject with completely excised basal cell carcinoma or squamous cell carcinoma of the skin and completely excised cervical cancer in situ are also considered eligible.

Preoperatively on the Day of Surgery:

• Exclusion criteria 1 to 17 are applicable at this time.
• Subject has AKI (any stage) present at presurgery baseline.
• Subject has known or suspected infection/sepsis at time of presurgery baseline.

Perioperative Exclusion Criteria:

• Subject requires Extracorporeal Membrane Oxygenation during or after completion of surgery.
• Subject requires ventricular assist device during or after completion of surgery.
• Subject has surgery performed "Off-Pump" at any time during surgery.

General:

• Subject has other condition, which makes the subject unsuitable for study participation.
• Female subject who is pregnant or lactating or has a positive pregnancy test within 72 hours prior to screening and/or randomization, has been pregnant within 6 months before screening assessment or breastfeeding within 3 months before screening or who is planning to become pregnant within the total study period.
• Subject has a known or suspected hypersensitivity to ASP1128 or any components of the formulation used.