A Clinical Trial to Evaluate Efficacy, Tolerability, and Pharmacokinetic-Pharmacodynamic Relationship of Fimasartan/Hydrochlorothiazide

Inclusion Criteria: 1. Male or female subjects of no childbearing potential 19-70 years of age 2. Mean clinic-measured sitting DBP (siDBP) of 90-109 mmHg and mean clinic-measured sitting SBP (siSBP) of 140-179 mmHg after a ≥1-week washout of prior antihypertensive medications (no wash-out is needed for those not on any antihypertensive medications) with a difference of ≤10 mmHg in sitting DBP between before and after run-in 3. Subjects who agree to participate in this study and give written informed consent 4. Subjects considered to understand the study, be cooperative, and able to be followed-up until the end of the study Exclusion Criteria: 1. Severe hypertension, i.e., mean siDBP ≥110 mmHg or mean siSBP ≥180 mmHg 2. Orthostatic hypotension with clinically significant signs or symptoms 3. Secondary hypertension 4. Not able to stop administration other antihypertensive medications than the study drugs (i.e., fimasartan and hydrochlorothiazide) throughout the entire study period 5. Clinically significant abnormal laboratory test results, e.g., serum creatinine \>1.5 times upper limit of normal, AST, ALT \> 2 times upper limit of normal 6. Conditions that may affect to absorption, distribution, metabolism, and excretion for the study drugs 7. Severe insulin-dependent or uncontrolled diabetes mellitus (HbA1c \>9%, increased dose of an oral hypoglycemic agent within 12 weeks before screening, or active insulin treatment at screening) 8. Severe cardiovascular diseases within 6 months of screening including ischemic heart disease, peripheral vascular disease, significant ventricular tachycardia, atrial fibrillation, atrial flutter or other significant arrhythmia, hypertrophic obstructive cardiomyopathy, severe obstructive coronary artery disease, aortic stenosis, hemodynamically significant aortic valve or mitral valve disease, severe cerebrovascular disease 9. History of percutaneous transluminal coronary angiography or coronary artery bypass graft 10. Chronic debilitating disease, autoimmune disease, connective tissue disease 11. Positive on serum hepatitis B surface antigen, anti-hepatitis C virus antibody, or anti-HIV antibody 12. History or evidence of alcohol or drug abuse within 2 years 13. Known allergic reaction to any angiotensin receptor blockers 14. Chronic inflammation disease requiring chronic anti-inflammation therapy 15. Women of childbearing potential without any contraceptive measure or breast-feeding mother 16. Prior participation in a clinical trial of any investigational products within 12 weeks from screening 17. Serum potassium \<3.5 mmol/L or \>5.5 mmol/L at any time of the study period 18. Depletion of sodium ion or body fluid, which cannot be corrected easily during the study period 19. Evidence of hereditary disease, including galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption. 20. Considered unsuitable to participate in the study under the discretion of the principal investigator