Conditions: Type 2 Diabetes Mellitus
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 5570
Healthy volunteers: no

Brief summary:
To assess the effect of adding acarbose or repaglinide or gliclazide to sitagliptin plus metformin, compared to adding glimepiride, on glycemic improvements in Type 2 Diabetes Mellitus (T2DM) participants who require the addition of a third oral anti-hyperglycemic agent (OAHA) according to China Guideline for Type 2 Diabetes. The three co-primary hypotheses are that after 24 weeks of treatment in phase 2, the mean change from baseline in hemoglobin A1c (A1c) in participants receiving either (1)acarbose or (2)repaglinide or (3)gliclazide added to sitagliptin and metformin combination is non-inferior to that of participants receiving glimepiride added to sitagliptin and metformin combination. The study would be declared successful if at least one of the three primary hypotheses was met.

Detailed description:
Participants coming on study will be stabilized to a standardized metformin dose: this may take about 10 weeks, and then combination therapy with metformin + sitagliptin will begin during Phase 1 (Week 0 through Week 20). If a participant has already been on a stabilized metformin dose, they will start immediately on combination therapy with metformin + sitagliptin for 20 weeks (Phase 1).

In Phase 2, participants who have failed to achieve adequate glycemic control (A1c ≥ 7% and ≤ 10% at Week 16 and fasting finger stick glucose ≥130 mg/dL and ≤280 mg/dL at Week 20) will be randomized to receive add-on therapy with glimepiride, repaglinide, acarbose, or gliclazide for 24 weeks (Week 20 through Week 44).

Arms:
arm 1: During Phase 2, participants receive up to 6 mg glimepiride daily as an add-on to metformin + sitagliptin combination therapy for 24 weeks (Week 20 through Week 44). arm 2: During Phase 2, participants receive up to 16 mg repaglinide daily as an add-on to metformin + sitagliptin combination therapy for 24 weeks (Week 20 through Week 44). arm 3: During Phase 2, participants receive 50-100 mg acarbose three times daily as an add-on to metformin + sitagliptin combination therapy for 24 weeks (Week 20 through Week 44). arm 4: During Phase 2, participants receive 30-120 mg gliclazide daily as an add-on to metformin + sitagliptin combination therapy for 24 weeks (Week 20 through Week 44).

Interventions: intervention 1: Metformin intervention 2: Sitagliptin intervention 3: Acarbose intervention 4: Repaglinide intervention 5: Glimepiride intervention 6: Gliclazide
Intervention descriptions: intervention 1: Metformin, 500 mg or 850 mg oral tablets, twice or three times a day (BID or TID) for a total dose of at least 1500 mg daily; administered with food. intervention 2: Sitagliptin, 100 mg oral tablet, once daily (QD); administered with or without food intervention 3: Acarbose, 50 mg oral tablets, TID (150 mg total daily dose); administered with the first bite of each main meal. intervention 4: Repaglinide, 0.5 mg and/or 1 mg oral tablets, TID (up to 16 mg daily); administered within 30 minutes of each meal. intervention 5: Glimepiride, 1 mg and/or 2 mg oral tablets, QD (up to 6 mg daily); administered before the first main meal of the day intervention 6: Gliclazide, 30 mg oral tablets, QD or BID (30 mg to 120 mg total daily dose); administered with meal.

Protocol document: