The purpose of this first-in-human (FIH) study is to evaluate safety, tolerability, pharmacokinetic (PK) of OJR520.

This is a three-part randomized, participant- and investigator blinded, placebo-controlled, multi-center, sequential study: single ascending dose (SAD) in healthy volunteers (HV), SAD in participants with chronic kidney disease (CKD) or diabetic chronic kidney disease (DKD) and multiple ascending dose (MAD) in participants with CKD or DKD.

Inclusion Criteria:

Able to provide written informed consent before any assessment is performed.

Part A (HV):

• Healthy male and female participants in good health as determined by past medical history, physical examination, vital signs, 12-lead ECG, and laboratory tests at screening and baseline within the normal range.

Parts B & C (CKD)

• Male and female participants 18 to 65 years of age.

Exclusion Criteria:

• Women of childbearing potential.
• Sexually active males unwilling to use contraception.

Part A (HV):

• Clinically significant abnormal blood pressure, defined as SBP <90 mmHg or >140 mmHg or DBP <55 mmHg or >95 mmHg.
• Abnormal resting HR, defined as <45 bpm or >90 bpm.

Part B & C (CKD)

• History of, or currently active, significant illness or medical disorders including, but not limited to, cancer (except for non-melanoma skin cancer), heart failure NYHA III-IV, heart rhythm abnormalities (e.g., atrial fibrillation, sick sinus syndrome, permanent pacemaker), CKD due to autoimmune disease, kidney transplant, dialysis or any other disease the investigator believes may preclude the participant from participating in the this study.
• Clinically significant aortic stenosis or mitral insufficiency as identified via echocardiography.
• History of myocardial infarction (MI), stroke, coronary artery bypass graft (CABG), percutaneous coronary intervention (PCI), or transient ischemic attack (TIA).

Other protocol defined inclusion/exclusion criteria may apply.