A Double-blind Study to Evaluate the Efficacy and Safety of LCZ696 in Patients With Essential Hypertension Not Adequately Responsive to Amlodipine 5 mg Monotherapy Treatment

INTERVENTION: investigational material(s) Generic name etc : LCZ696 INN of investigational material : Therapeutic category code : 214 Antihypertensives Dosage and Administration for Investigational material : Once daily, 200mg control material(s) Generic name etc : Amlodipine INN of investigational material : Amlodipine Therapeutic category code : 214 Antihypertensives Dosage and Administration for Investigational material : Once daily, 5mg CONDITION: Essential hypertension PRIMARY OUTCOME: Change in mean 24‐hour ABPM systolic blood pressure (maSBP) [ Time Frame: 8 weeks ]; Measure the change in mean 24 hour ambulatory systolic blood pressure (maSBP) from baseline to end of the study (week 8) in the 2 groups. A greater reduction from baseline in the LCZ696 group will indicate whether there is a positive treatment effect. INCLUSION CRITERIA: ‐Patients must have a diagnosis of hypertension: ‐Untreated patients must have an msSBP >= 150 mmHg and < 180 mmHg at both Visit 1 and Visit 101. ‐Pre‐treated patients must have an msSBP >= 145 mmHg and < 180 mmHg after wash out at Visit 101. ‐All patients must have an office msSBP >= 145 mmHg and < 180 mmHg at the completion of the 4‐week run‐in epoch (at the randomization visit (Visit 201). ‐Patients must successfully complete ABPM and pass technical requirements at Visit 201. SECONDARY OUTCOME: Change in mean 24‐hour ABPM diastolic blood pressure (maDBP) [ Time Frame: 8 weeks ]; Measure the change in mean 24 hour ambulatory diastolic blood pressure (maDBP) from baseline to end of the study. A reduction from baseline will indicate whether there is a positive treatment effect.; Change in mean sitting systolic blood pressure (msSBP) [ Time Frame: 8 weeks ]; Measure the change in the patient's mean sitting systolic blood pressure (msSBP) from baseline to end of the study. A reduction from baseline will indicate whether there is a positive treatment effect.; Change in mean sitting diastolic blood pressure (msDBP) [ Time Frame: 8 weeks ]; Measure the change in the patient's mean sitting diastolic blood pressure (msDBP) from baseline to end of the study. A reduction from baseline will indicate whether there is a positive treatment effect.; ; Change in sitting pulse pressure [ Time Frame: 8 weeks ]; Measure the change in the patient's mean sitting pulse pressure from baseline to end of the study. Pulse pressure measures the difference in mean sitting systolic blood pressure and mean sitting diastolic blood pressure.; Percentage of patients achieving systolic and diastolic blood pressure control (< 140/90 mmHg) [ Time Frame: 8 weeks ] ; The Percentage of patients achieving a systolic and diastolic blood pressure < 140/90 mmHg is a measure of how well a given blood pressure treatment can achieve a given blood pressure target or goal. Patient that achieve the target blood pressure will be determined based on the mean sitting diastolic and systolic blood measurements taken at the end of the study. If the patient BP measurement is below the above target they will be deemed as a success.; Percentage of patients achieving successful response in msSBP (< 140 mmHg or a reduction >= 20 mmHg from baseline) [ Time Frame: 8 weeks ] ; The percentage of patients that achieve successful treatment response in the mean sitting systolic blood pressure (msSBP) of < 140mmHg or a reduction >= 20 mmHg from baseline after completing study treatment. Patients that achieve either of the above targets will be deemed as a having a successful response.; Percentage of patients achieving successful response in msDBP (< 90 mmHg or a reduction >= 10 mmHg from baseline) [ Time Frame: 8 weeks of treament ]; The percentage of patients that achieve successful treatment response in the mean sitting diastolic blood pressure (msDBP) of < 90mmHg or a reduction >= 10mmHg from baseline after completing study treatment. Patients that achieve either of the above targets will be deemed as having a successful response.; Number of patients with adverse event [ Time Frame: 8 weeks ]; Summarized statistics on adverse events will be reported under categories such as total adverse events, serious adverse events and death.