Many people with type 2 diabetes cannot maintain their target blood glucose levels on a single therapy. The purpose of this study is to assess the safety and effectiveness of vildagliptin, an unapproved drug, in lowering overall blood glucose levels when added to insulin in people with type 2 diabetes who are not at target blood glucose levels on insulin alone.

Inclusion Criteria:

• Blood glucose criteria must be met
• On a stable dose of insulin as defined by the protocol
• Body mass inde (BMI) in the range 22-45

Exclusion Criteria:

• Type 1 diabetes
• Pregnancy or lactation
• Evidence of serious diabetic complications
• Evidence of serious cardiovascular complications
• Laboratory value abnormalities as defined by the protocol
• Other protocol defined exclusion criteria may apply