Efficacy and Safety of the Combination Aliskiren (300 mg) and Hydrochlorothiazide (25mg) to Aliskiren (300mg) Monotherapy in Patients With Staged II Hypertension (ACQUIRE)

• Change in Mean Sitting Systolic Blood Pressure (msSBP) From Baseline to Week 8 [ Time Frame: Baseline to Week 8 ] [ Designated as safety issue: No ]
  At the first visit, blood pressure (BP) was measured in both arms and the arm having the higher BP reading was the arm used for all subsequent readings throughout the study. Patients were required to sit for five minutes with feet flat on the floor, with arm resting so that the bottom of the cuff was at the same level as the heart. BP was measured three times at 1 to 2-minute intervals at each visit using the correct cuff size. The mean BP was calculated from the 3 readings.
• Change in Mean Sitting Diastolic Blood Pressure (msDBP) From Baseline to Week 8 and to Week 12 [ Time Frame: Baseline to Week 12 ] [ Designated as safety issue: No ]
  At the first visit, blood pressure (BP) was measured in both arms and the arm having the higher BP reading was the arm used for all subsequent readings throughout the study. Patients were required to sit for five minutes with feet flat on the floor, with arm resting so that the bottom of the cuff was at the same level as the heart. BP was measured three times at 1 to 2-minute intervals at each visit using the correct cuff size. The mean BP was calculated from the 3 readings.
• Percentage of Patients Achieving the Target Blood Pressure (msSBP < 140 mm Hg and msDBP < 90 mm Hg, and msSBP < 130 mm Hg and msDBP < 80 mm Hg for Diabetics) at Week 8 and Week 12 [ Time Frame: Baseline to Week 12 ] [ Designated as safety issue: No ]
  At the first visit, blood pressure (BP) was measured in both arms and the arm having the higher BP reading was the arm used for all subsequent readings throughout the study. Patients were required to sit for five minutes with feet flat on the floor, with arm resting so that the bottom of the cuff was at the same level as the heart. BP was measured three times at 1 to 2-minute intervals at each visit using the correct cuff size. The mean BP was calculated from the 3 readings.

• Change from baseline in msSBP (after 8 weeks of treatment) and in msDBP ( after 12 and 8 weeks of treatment)for aliskiren / HCTZ (300/25 mg) combination vs. aliskiren (300 mg) monotherapy [ Time Frame: 8 and 12 weeks ] [ Designated as safety issue: No ]
• Change from baseline in msSBP and msDBP after 12 and 8 weeks of treatment with aliskiren / HCTZ (300/25 mg) combination [ Time Frame: 8 and 12 weeks ] [ Designated as safety issue: No ]
• Change from baseline in msSBP and msDBP after 12 and 8 weeks of aliskiren (300 mg) monotherapy. [ Time Frame: 8 and 12 weeks ] [ Designated as safety issue: No ]
• Proportion of patients achieving the target blood pressure (msSBP < 140 mmHg and msDBP < 90 mmHg, and msSBP < 130 mmHg and msDBP < 80 mmHg for diabetics), in both study arms, after 12 and 8 weeks of treatment. [ Time Frame: 8 and 12 weeks ] [ Designated as safety issue: No ]
• Safety and tolerability of aliskiren / HCTZ (300/25 mg) combination compared to aliskiren (300 mg) monotherapy regimen in patients with Stage II hypertension. [ Time Frame: 12 weeks ] [ Designated as safety issue: No ]

This study will compare the efficacy and safety of once daily dosing of aliskiren monotherapy to once daily dosing of aliskiren and hydrochlorothiazide combination therapy in patients with Stage II hypertension over a period of 12 weeks.

• Drug: Aliskiren/hydrochlorothiazide (HCTZ) (300/25 mg)
  During the titration period, patients received aliskiren/hydrochlorothiazide (HCTZ) 150/12.5 mg for 1 week.
• Drug: Aliskiren (300 mg)
  During the titration period, patients received aliskiren 150 mg for one week. Subsequently, patients were up-titrated and received aliskiren 300 mg.

• Experimental: Aliskiren/hydrochlorothiazide (HCTZ) (300/25 mg)
  Intervention: Drug: Aliskiren/hydrochlorothiazide (HCTZ) (300/25 mg)
• Active Comparator: Aliskiren (300 mg)
  Intervention: Drug: Aliskiren (300 mg)

Inclusion Criteria:

• Outpatients ≥18 years of age.
• Patients with a diagnosis of Stage II hypertension, defined as mean sitting Systolic Blood Pressure (msSBP) ≥ 160 mmHg and < 180 mmHg at Visit 2.

Exclusion Criteria:

• Severe hypertension defined as msSBP ≥ 180 mmHg and/or mean sitting Diastolic Blood Pressure (msDBP) ≥ 110 mmHg.
• Secondary form of hypertension.
• Current diagnosis of heart failure (New York Heart Association [NYHA] Class II-IV).
• Current angina pectoris requiring pharmacological therapy (other than stable doses of oral or topical nitrates).
• Second or third degree heart block without a pacemaker.
• Concurrent potentially life threatening arrhythmia or symptomatic arrhythmia, atrial fibrillation or atrial flutter, during the 12 months prior to Visit 1.
• Clinically significant valvular heart disease.
• Previous history of hypertensive encephalopathy or stroke, Transcient Ischemic Attack (TIA), heart attack, coronary bypass surgery or any PCI.
• Known Keith-Wagener grade III or IV hypertensive retinopathy.
• In the month prior to Visit 1, patients on combination antihypertensive therapy that includes more than 2 classes of antihypertensive medications.
• Patients on combined antihypertensive medication that contain two classes of antihypertensive medications are considered to take two antihypertensive medications.
• Inability to discontinue prior antihypertensive or other CV medications as required by the protocol.
• Patients with Type 1 diabetes mellitus.
• Patients with Type 2 diabetes mellitus not well controlled .
• Elevated Serum potassium (over 5.3 mEq/L (mmol/L).
• Any surgical or medical condition or the use of any medication which might significantly alter the absorption, distribution, metabolism, or excretion of study drugs.

Other protocol-defined inclusion/exclusion criteria may apply.