A Study to Evaluate the Efficacy and Safety of BR1015 Combination Therapy

* Inclusion Criteria: * Patients with uncontrolled essential hypertension at screening(V1) under the following criteria: * Naïve : 140 mmHg ≤ SiSBP \< 180 mmHg * Use antihypertensive drugs : 130 mmHg ≤ SiSBP \< 180 mmHg * Patients with uncontrolled essential hypertension at randomization(V2) after Fimasartan 30mg monotherapy for 4 weeks under the following criteria: * Selected reference arm : 140 mmHg ≤ SiSBP \< 180 mmHg (For patients with cardiovascular disease, diabetes or chronic kidney disease (CKD) with albuminuria, 130 mmHg ≤ SiSBP \< 180 mmHg) * Treatment compliance of Fimasartan 30 mg ≥70% at baseline visit (V2) * Voluntarily provided a written consent to participate in this clinical study * Able to understand this study, be cooperative in the execution of the study, and participate in the study until its completion * Exclusion Criteria: * Patients taking three or more antihypertensive drugs of different families * Patients with blood pressure results showing SiSBP ≥ 180 mmHg or SiDBP ≥ 110 mmHg in the selected reference arm at screening(V1) and randomization(V2) * Patients with a difference of SiSBP ≥ 20 mmHg and SiDBP ≥ 10 mmHg in blood pressure measured three times on both arms at screening(V1) * Patients with secondary hypertension: Secondary hypertension is not limited to the following diseases; (e.g., coarctation of the aorta, Primary hyperaldosteronism, renal artery stenosis, Cushing's syndrome, pheochromocytoma and polycystic kidney disease, etc.) * Patients with orthostatic hypotension accompanied by symptoms * Patients who need to be administered in combination with antihypertensive drugs other than investigational product while participating in clinical trials