Conditions: Type 2 Diabetes Mellitus
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 337
Healthy volunteers: no

Brief summary:
This study will evaluate the effect of the addition of metformin once daily (q.d.) or twice daily (b.i.d.) to sitagliptin monotherapy in Japanese participants with Type 2 diabetes mellitus (T2DM) who have inadequate glycemic control with diet/exercise therapy and sitagliptin monotherapy. The primary hypotheses are that the addition of metformin 250 mg b.i.d. or metformin 500 mg q.d. is superior to the addition of placebo on the change from baseline in hemoglobin A1c (HbA1c) at 24 weeks and that the addition of metformin 500 mg q.d. is non-inferior to the addition of metformin 250 mg b.i.d. on the change from baseline in HbA1c at 24 weeks.

Detailed description:

Arms:
arm 1: Participants will receive sitagliptin daily (continuing their pre-study dose), 2 metformin 250 mg tablets in the morning and 1 matching placebo tablet in the evening. arm 2: Participants will receive sitagliptin daily (continuing their pre-study dose), 1 metformin 250 mg tablet and 1 matching placebo tablet in the morning and 1 metformin 250 mg tablet in the evening. arm 3: Participants will receive sitagliptin daily (continuing their pre-study dose), 2 matching placebo tablets in the morning and 1 matching placebo tablet in the evening.

Interventions: intervention 1: Sitagliptin intervention 2: Metformin intervention 3: Metformin intervention 4: Placebo
Intervention descriptions: intervention 1: Sitagliptin, orally, 50 or 100 mg tablet (continuation of the pre-study dose) intervention 2: Metformin, orally, 500 mg daily (single dose; two 250 mg tablets) for 24 weeks intervention 3: Metformin, orally, 500 mg daily (divided dose; 250 mg tablet b.i.d.) for 24 weeks intervention 4: Placebo to match metformin 250 mg tablets, orally, for 24 weeks

Protocol document: