• Percentage of non-Chronic Kidney Disease (CKD) patients with a Mean sitting Systolic Blood Pressure < 95th percentile for gender, age and height [ Time Frame: baseline to week 26 ] [ Designated as safety issue: No ]
• Mean seated systolic blood pressure reduction in non-CKD patients [ Time Frame: from baseline to week 26. ] [ Designated as safety issue: No ]
• Mean ambulatory blood pressure reduction as measured by 24 hour ABPM. [ Time Frame: from baseline to week 26 ] [ Designated as safety issue: No ]
• Percentage of CKD patients treated achieving urine protein/creatinine ratio (UPCR) reduction by ≥ 25% [ Time Frame: from week 12 to week 26 ] [ Designated as safety issue: No ]
• Percentage of CKD patients who have urine protein/creatinine ratio (UPCR) reduced by ≥ 50% [ Time Frame: from baseline to week 26 ] [ Designated as safety issue: No ]

• Evaluate the percentage of non-Chronic Kidney Disease (CKD) patients treated with valsartan or enalapril alone with a Mean sitting Systolic Blood Pressure < 95th percentile for gender, age and height from baseline to week 26 (responder).
• Evaluate the mean seated systolic blood pressure reduction in non-CKD patients treated with valsartan or enalapril alone from baseline to week 26 (BP reduction).
• Evaluate the mean ambulatory blood pressure reduction for all patients (participating in ABPM) from baseline to week 26 as measured by 24 hour ABPM.
• Evaluate the percentage of CKD patients treated with valsartan and enalapril combination or enalapril monotherapy achieving urine protein/creatinine ratio (UPCR) reduction by ≥ 25% from week 12 to week 26
• Evaluate the percentage of CKD patients on valsartan and enalapril combination vs. enalapril monotherapy who have urine protein/creatinine ratio (UPCR) reduced by ≥ 50% from baseline to week 26

The purpose of this extension study is to compare the long term safety of valsartan versus enalapril, and the effectiveness of the combination of valsartan and enalapril versus enalapril alone in children with Chronic kidney disease (CKD). In addition it will evaluate proteinuria reduction, renopreservation, and tolerability of valsartan and enalapril combination vs. enalapril monotherapy alone in patients with chronic kidney disease.

Inclusion Criteria:

• Successful completion of 12 weeks of double blind treatment in core protocol CVAL489K2302.
• Patients participating in study CVAL489K2302 who may have discontinued prematurely due to uncontrolled hypertension defined as; MSSBP >20%, but <25% above the 95th percentile for age, gender, and height after visit 5, qualifies a patient for entry into this extension study.

Exclusion Criteria:

• Renal artery stenosis
• Current diagnosis of heart failure (NYHA Class II-IV).
• Second or third degree heart block without a pacemaker.
• Concurrent potentially life threatening arrhythmia or symptomatic arrhythmia.
• Clinically significant valvular heart disease.
• Patient that demonstrates clinically significant ECG abnormalities other than those associated with left ventricular hypertrophy and AV block controlled with a pacemaker
• Previous solid organ transplantation except renal, liver or heart transplantation. Renal, liver or heart transplant must have occurred at least 6 months prior to enrollment. Patient must be on stable doses of immunosuppressive therapy for 3 months and deemed clinically stable by the investigator.

Other protocol-defined inclusion/exclusion criteria may apply