Key Inclusion Criteria:  Part A  Participants must be 20 to 60 years of age inclusive, at the time of signing the informed consent Participants who have a fasting LDL-C ≥ 70 mg/dL but < 140 mg/dL at screening Participants who have fasting triglycerides < 400 mg/dL at screening Participants who should be receiving statin therapy Participants who should be on stable medication for a certain time period prior to randomization Body mass index (BMI) between 19 and 40 kg/m2 Females must not be pregnant and must have a negative pregnancy test at screening and randomisation, must not be lactating , and must be of nonchild-bearing potential  Part B  Participants must be 20 to 75 years of age inclusive, at the time of signing the informed consent Have a fasting LDL-C ≥ 70 mg/dL but < 190 mg/dL at screening (Visit 2) Have fasting triglycerides < 400 mg/dL at screening (Visit 2) Should be receiving statin therapy LDL-lowering medications should be on stable dosing for ≥ 3 months prior to screening with no planned medication or dose change during study participation BMI between 19 and 40 kg/m2 Female participants must not be pregnant and must have a negative pregnancy test at screening and randomisation, must not be lactating, and must not be of childbearing potential  Key Exclusion Criteria:  Part A  eGFR < 60 mL/min/1.73m2 using the Japanese equation Blood dyscrasias with increased risk of bleeding including idiopathic thrombocytopenic purpura and thrombotic thrombocytopenic purpura or symptoms of increased risk of bleeding. Or participants receiving anti-coagulation therapy History of major bleed or high-risk of bleeding diathesis Subjects with a high 10-year risk of coronary heart disease as calculated using the Suita score Heart rate after 10 minutes of sitting rest < 50 or > 100 beats per minute Uncontrolled hypertension defined as sitting SBP > 140 mmHg or DBP > 90 mmHg  Part B  eGFR < 40 mL/min/1.73m2 using the Japanese equation at Visit 1 Poorly controlled type 2 diabetes mellitus (T2DM), defined as Haemoglobin A1c (HbA1c) > 10% at Visit 1 Acute ischaemic cardiovascular event in the last 12 months prior to randomization Heart failure with New York Heart Association (NYHA) Class III-IV High-risk of bleeding diathesis as judged by the Investigator Uncontrolled hypertension defined as sitting SBP > 160 mmHg or DBP > 90 mmHg at Visit 1 or Visit 3 Heart rate after 10 minutes sitting rest < 50 bpm or > 100 bpm at Visit 1 or Visit 3