This study will evaluate the long-term safety and efficacy of dutogliptin in patients with type 2 diabetes mellitus (T2DM).

Inclusion Criteria:

• Have successfully completed all required visits of a qualifying Phase 3 core protocol
• Be currently receiving treatment for T2DM as set forth in the qualifying Phase 3 core protocol

Exclusion Criteria:

• Any condition, disease, disorder or clinically relevant laboratory abnormality which, in the opinion of the investigator, would jeopardize the patient's appropriate participation in this study or obscure the effects of treatment