A Phase 3 Long-term Study of TAK-536 in Pediatric Patients 6 to Less Than 16 Years With Hypertension

Inclusion Criteria

• In the opinion of the investigator or subinvestigator, the participant's parent or the participant's legal guardian is capable of understanding and complying with protocol requirements.
• The participant's parent or the participant's legal guardian is capable of signing and dating a written, informed consent form on behalf of the participant prior to the initiation of any study procedures. Written informed assent is also obtained from the participant as much as possible.
• The Japanese participant who has a diagnosis of hypertension. A participant is eligible if he/she is deemed hypertensive according to the Reference Blood Pressure Values of Children by Gender and Age; office sitting diastolic or systolic blood pressure ≥ 95 percentile for essential hypertension without concomitant hypertensive organ damage, and ≥ 90 percentile for secondary hypertension with concomitant chronic kidney disease (CKD), diabetes mellitus, heart failure or any hypertensive organ damage.

In addition, participants need to meet the following criteria:

• If currently treated with any antihypertensive drugs at the start of the Run-in Period: Participant has a documented historical diagnosis of hypertension and an office sitting diastolic or systolic blood pressure meeting the above criteria at the end of the Run-in Period (Week 0).
• If currently untreated with any antihypertensive drugs at the start of the Run-in Period: Participant who meets the above criteria on 3 separate time points including screening and the end of the Run-in Period (Week 0). In addition, participant with essential hypertension without concomitant hypertensive organ damage still maintains hypertension with non-pharmacotherapy including foods or exercises for at least 3 months within 1 year prior to the start of screening.
• The participant is male or female and aged 6 to less than 16 years at the time of informed consent.
• The participant weighs at least 20 kg at screening.
• The participant is capable of taking the tablets or granules supplied as the study drug.
• A participant who has undergone kidney transplantation is eligible if he/she underwent the transplantation at least 6 months earlier at screening, and the graft has been functionally stable (estimated glomerular filtration rate (eGFR) ≥ 30 mL/min/1.73 m^2) for at least 6 months with evidence (eg, Doppler echography, computed tomography (CT) scan or magnetic resonance imaging (MRI) excluding grafted kidney arterial stenosis. A participant on immunosuppressive therapy with a stable dose at least 30 days prior to screening is eligible.
• A female participant of childbearing potential who is sexually active with a nonsterilized male partner agrees to use routinely adequate contraception from signing of informed consent through 1 month after the completion of the study, and proves negative in the pregnancy test at screening.
• The participants judged by the investigator or subinvestigator that he/she can discontinue the therapy with renin-angiotensin-system (RAS) inhibitors for 2 weeks (acceptable range, 1 to 4 weeks) in safe prior to the Treatment Period.

Exclusion Criteria

• The participant has received any investigational compound within 30 days prior to screening or is participating in another clinical study or a post-marketing clinical study.

Note: This does not apply to participants participating in observational studies without interventional or invasive therapy.

• The participant previously received therapy with azilsartan. Note: This does not apply to participants participating in single dose pharmacokinetic studies of TAK-536.
• The participant has poorly controlled hypertension indicated by an office sitting systolic blood pressure higher by at least 15 mmHg and/or an office sitting diastolic blood pressure higher by at least 10 mmHg than the 99 percentiles of the Reference Blood Pressure Values of Children by Gender and Age.
• The participant has a diagnosis of malig