Study to Confirm the Efficacy and Safety of Fixed-dose Combinations of Amlodipine and Candesartan

Inclusion Criteria:

1. Adult male and female aged 19 to 75 years

2. Diagnosed with essential hypertension Patients with essential hypertension meeting one of the following two inclusioncriteria:

2.1. Patients with essential hypertension who have shown inadequate response (meansiSBP ≥ 140 mmHg or mean siDBP ≥ 90 mmHg) to treatment with amlodipine or candesartancilexetil.

2.2. Patients with essential hypertension with blood pressure adequately controlled byco-administration of amlodipine besylate and candesartan cilexetil (mean siSBP < 140mmHg and mean siDBP < 90 mmHg).

3. Voluntarily consented to participate in the study and signed the informed consent formafter receiving the explanation of the objectives, methods and effects of the study.

Exclusion Criteria:

1. The difference in blood pressure between the selected arm versus non-selected arm is ≥ 20 mmHg for siSBP and ≥ 10 mmHg for siDBP at Visit 1 (screening).

2. Blood pressure taken at screening and randomization is ≥ 180 mmHg for siSBP or ≥ 110mmHg for siDBP.

3. Diagnosed with secondary hypertension or suspected of secondary hypertension [e.g.,renovascular disease, adrenal medullary and cortical hyperfunction, coarctation of theaorta, hyperaldosteronism, unilateral or bilateral renal artery stenosis, Cushing'ssyndrome, pheochromocytoma, polycystic kidney disease, etc.]

4. Patients with symptomatic orthostatic hypertension (the difference in the bloodpressures between measured at supine position and measured at standing position is ≥ 20 mmHg for siSBP and ≥ 10 mmHg for siDBP)

5. Diagnosis of type 1 diabetes mellitus (DM) or uncontrolled DM (patients on insulintherapy or with HbA1c > 9%)

6. Patients with severe cardiac conditions: heart failure (NYHA Class 3 or 4), history ofischemic cardiac disease (unstable angina, myocardial infarction), peripheral vasculardiseases, percutaneous transluminal angioplasty or coronary artery bypass graft withinrecent 6 months.

7. Patients with clinically significant ventricular tachycardia, atrial fibrillation,atrial flutter or other clinically significant arrhythmia at the discretion of theinvestigator

8. Patients with hypertrophic occlusive myocardiopathy, severe occlusive coronary arterydisease, aortic stenosis, hemodynamically significant aortic valve or mitral valvestenosis

9. History of cardiogenic shock

10. Presence of severe cerebrovascular disorders (diagnosis of stroke, cerebral infarctionor cerebral hemorrhage within recent 6 months)

11. History or current evidence of wasting, autoimmune (such as rheumatoid arthritis andsystemic lupus erythematosus) or connective tissue diseases

12. Known diagnosis of moderate or malignant retinopathy (including retinal hemorrhage,visual disturbance and retinal microaneurysm within 6 months)

13. Patients with surgical or medical intestinal diseases or having received surgeriesthat could interfere with drug absorption distribution, metabolism and elimination

14. History of malignancy including leukemia and lymphoma within recent 5 years except forlocalized basal cell carcinoma of the skin)

15. Patients with any inflammatory diseases requiring chronic anti-inflammatory therapy

16. Renal failure on dialysis

17. Laboratory abnormalities as follows:

• AST or ALT >2 x upper limit of normal (ULN)

• Serum creatinine > 1.5 x ULN

• Serum potassium < 3.5 mmol/L or >5.5 mmol/L

18. Needs for co-administration of non-study antihypertensive agents or contraindicatedmedications during the study

19. History of hypersensitivity to ARBs or dihydropyridines

20. History of angioedema to treatment with ACE inhibitors or ARBs

21. Pregnant or lactating women and female volunteers of childbearing potential (exceptfor women who are surgically sterile) who are not willing to use an adequate method ofcontraception (oral contraceptives, intrauterine device, condom, etc.) during thestudy. Women of childbearing potential who are not surgically sterile will be allowedto participate in the study only if they have negative pregnancy test at Visit 1 (screening) and should continue to use medically acceptable method of contraception (basic body temperature method and rhythm method will not be allowed). Women with nomenses for ≥ 12 months will be considered as postmenopausal state and method ofcontraception using hormonal contraception such as oral contraceptive should beinitiated from or prior to the screening.

22. History of drug or alcohol abuse within recent 1 year

23. Patients having received any other investigational product within recent 12 weeks

24. Conditions which render a subject ineligible for the study at the discretion of theinvestigator