Efficacy/Safety of Vildagliptin and Metformin Combination Therapy in Patients With Type 2 Diabetes Not Well Controlled With Metformin Alone

Inclusion Criteria: * 18-78 years inclusive * Type 2 diabetes diagnosis at least 2 months prior to study entry * Body mass index in the range of 22-45 kg/m2 * HbA1c in the range of 6.5 to 9% inclusive * Fasting plasma glucose \<270 mg/dL (15 mmol/L) Exclusion Criteria: * A history of type 1 diabetes * Evidence of significant diabetic complications * Treatment with insulin or any other oral antidiabetic agents * Congestive heart failure requiring pharmacologic treatment * Clinically significant renal dysfunction defined by metformin labeling criteria (serum creatinine levels \>/= 1.5 mg/dl (males) and \>/= 1.4 mg/dl (females) Other protocol-defined inclusion/exclusion criteria may apply