This crossover study will assess the effect of 2 doses of Taspoglutide on first- and second-phase insulin secretion in patients with type 2 diabetes. Patients will receive a continuous subcutaneous infusion of a)the Immediate Release Formulation (IRF)of Taspoglutide 300 micrograms/day for 2 days followed by Taspoglutide 800 micrograms/day for 2 days or b)saline placebo for 2+2 days. After a washout period of 10-15 days, patients will be crossed-over for further treatment;those receiving Taspoglutide in period 1 will receive placebo in period 2, and vice versa. On days 2 and 4 of each period, insulin secretion patterns will be assessed. The anticipated time on study treatment is <3 months, and the target sample size is <100 individuals.

Inclusion Criteria:

• adult patients, 18-65 years of age;
• type 2 diabetes mellitus;
• treated with diet and exercise alone, or in combination with stable metformin for at least 3 months prior to screening.

Exclusion Criteria:

• type 1 diabetes mellitus;
• type 2 diabetes duration of <3 months;
• treatment with any oral anti-hyperglycemic medication other than metformin monotherapy during last 3 months;
• treatment with insulin for >7 days within 6 months prior to screening.