Efficacy and Safety of ENN0403 in Patients At High Risk for Acute Kidney Injury Following Elective Cardiac Surgery

Inclusion Criteria:

1. Ability to understand and comply with the study requirements and able to providewritten informed consent;

2. Age ≥18 and ≤85 years;

3. Male subjects (and their fertile female spouses/partners) do not have pregnancyplans during the screening period and within 3 months after the last dose,voluntarily take highly effective contraception, and must not donate sperm or ova.Only non-fertile women will be enrolled, and female subjects who meet the followingcriteria are not considered fertile: Postmenopausal status has been achieved, normalmenstruation has stopped for at least 12 consecutive months with an FSH >30 IU/L inthe absence of other pathophysiological causes, or there is a medical record showinghysterectomy \ bilateral tubal resection and/or bilateral ovariectomy.

4. Subjects must be scheduled for cardiac surgery requring cardiopulmonary bypass:Coronary artery bypass grafting (CABG) and/or heart valve surgery and/or aorticroot, ascending aorta and aortic arch surgery;

5. Subjects have the risk of developing AKI with at least one of the followingcriteria: coronary artery bypass grafting combined with one or more heart valvessurgery plus at least one risk factor for AKI; Multiple heart valves surgery plus atleast one AKI risk factor; Coronary artery bypass grafting or aortic valve surgerycombined with aortic root, ascending aorta, and aortic arch surgery (non-aorticdissection) plus at least one risk factor for AKI; Coronary artery bypass graftingalone or single heart valve surgery plus at least 2 risk factors for AKI.

Exclusion Criteria:

1. Receive ICD or permanent pacemaker implantation, mechanical ventilation, IABP, LVADor other mechanical circulatory AIDS within 1 week before surgery;

2. Cardiopulmonary resuscitation is performed within 14 days prior to screening;

3. Abnormal renal function with eGFR<20 mL/min/1.73 m2 within 30 days before screening;

4. Receive renal replacement therapy or the presence of AKI within 30 days beforesurgery, except for transient (≤5 days) stage 1 AKI after iodized contrast agentexposure;

5. Participate in other clinical trials within the past 1 month;

6. Have a known allergy to investigational drug or any of its constituents, or alleryto any constituents used during the study;

7. Subjects with intractable hypotension, severe hypoxemia or other emergency duringsurgery.