Comparison of the combination of amlodipine with an angiotensin receptor blocker or an angiotensin converting inhibitor, on central arterial blood pressure in patients with hypertension and additional risk factors. This is a randomised, double-blind, double-dummy, multicenter study. The duration of active treatment 24 weeks.

The study, multi-center balanced, parallel group (two treatment arms), randomized, double-blind (double-dummy), non-inferiority study is designed to show non-inferiority of Sevikar® (olmesartan(OM)/amlodipine (AM)) 40/10 mg compared to the combination of Perindopril (PER) 8 mg plus Amlodipine 10 mg with regard to central systolic blood pressure lowering effect, using the change from baseline (Week 0) to final examination (Week 24).

Male and female Caucasians aged ≥ 40 years and <80 years with moderate to severe hypertension, defined by a systolic blood pressure (SBP) ≥ 160 and ≤ 200 or diastolic blood pressure (DBP) ≥ 100 and ≤ 115 mmHg for untreated patients, SBP ≥ 140 or DBP ≥ 90 mmHg for insufficiently pre-treated patients and SBP ≥ 130 mmHg or DBP ≥ 80 mmHg for insufficiently pretreated diabetics chronic kidney disease will be eligible for participation. In addition,three additional risk factors should be present.

During the course of the study three central blood pressure measurements (at randomization, at week 12 and at termination) will be performed with SphygmoCor ultrasound method. The conventional measurements with calibrated tensiometers (Omron) will be performed at each visit. Ambulatory blood pressure monitoring will be performed at randomisation.

The study starts with a 2-4 week run in phase. AM will be given as open-labelled 5 mg or 10 mg tablets, administered once daily. After randomization during the double-blind phase, study medication will comprise either OM/AM 40/10 mg or PER 8 mg (2x4 mg) plus AM 10 mg and will be administered once daily. Furthermore, open-label HCTZ 12.5 mg and 25.0 mg will be provided in tablets and administered once daily according to the treatment schedule.

The primary endpoint is the change in central SBP from baseline (Week 0, Visit 0) to final examination (Week 24, Visit 5) using Last Observation Carried Forward (LOCF) approach.

The study is conducted in approximately 15 centres in Spain. Depending on the previously administered drugs the run in phase is up to four weeks (Visits -2 and -1). Individual duration of active treatment (after randomization) will last 24 weeks (Visits 0-5). The total individual duration is 28 weeks.

A total of 518 patients (259 patients/arm) will be needed in the Per Protocol Set (PPS) for the confirmatory primary analysis using mean change from baseline (Week 0) to Final Examination assuming a drop out rate of 20% during Run-in Phase a total of 720 patients have to be screened in order to achieve 576 (288 patients/arm) randomised patients.

Assuming approximately 10% major protocol deviations, a total of 518 patients will remain in the PPS.

Inclusion Criteria:

• moderate to severe hypertension
• 3 additional risk factors such as age > 55 (male), > 65 female, smoker, type 2 diabetes, obesity, cardiovascular disease, congestive heart failure, chronic kidney disease,
• ability to give informed consent

Exclusion Criteria:

• secondary or malignant hypertension
• contraindication to any of the study drugs
• Creatinine clearance level <40ml/min
• treatment with more than 3 antihypertensive drugs
• Myocardial infarction, percutaneous transluminal coronary angioplasty, cardiac bypass surgery < 6 month prior to start of the study,
• unstable angina pectoris,
• stroke, transient ischemic attack < 3 months prior to start,
• Congestive heart failure NYHA II-IV,
• clinically relevant concomitant diseases,
• alcohol or drug abuse,
• pregnancy or women of childbearing potential without contraceptive precaution,

De-identified individual participant data (IPD) and applicable supporting clinical trial documents may be available upon request at https://vivli.org/. In cases where clinical trial data and supporting documents are provided pursuant to our company policies and procedures, Daiichi Sankyo will continue to protect the privacy of our clinical trial participants. Details on data sharing criteria and the procedure for requesting access can be found at this web address: https://vivli.org/ourmember/daiichi-sankyo/

Studies for which the medicine and indication have received European Union (EU) and United States (US), and/or Japan (JP) marketing approval on or after 01 January 2014 or by the US or EU or JP Health Authorities when regulatory submissions in all regions are not planned and after the primary study results have been accepted for publication.

Formal request from qualified scientific and medical researchers on IPD and clinical study documents from clinical trials supporting products submitted and licensed in the United States, the European Union and/or Japan from 01 January 2014 and beyond for the purpose of conducting legitimate research. This must be consistent with the principle of safeguarding study participants' privacy and consistent with provision of informed consent.