A Study in China Evaluating the Safety and Efficacy of Adding Sitagliptin to Stable Therapy With Sulfonylurea With or Without Metformin in Participants With Type 2 Diabetes Mellitus (T2DM) (MK-0431-253)

A Phase III, Multicenter, Randomized, Double-Blind, Placebo-Controlled Clinical Trial in China to Study the Safety and Efficacy of the Addition of Sitagliptin in Patients With Type 2 Diabetes Mellitus Who Have Inadequate Glycemic Control on Sulfonylurea Therapy, Alone or in Combination With Metformin

A study to compare safety and efficacy of sitagliptin and placebo therapy when added to stable sulfonylurea alone or in combination with metformin in participants with type 2 diabetes mellitus (T2DM). The primary hypothesis of this study is that after 24 weeks, the addition of sitagliptin compared with placebo provides greater reduction in hemoglobin A1C (HbA1C) in T2DM participants on sulfonylurea alone or in combination with metformin.

Inclusion Criteria:

• has T2DM
• is currently on a stable regimen of gliclazide or glimepiride, either alone or in combination with metformin for ≥ 10 weeks
• has a Visit 1/Screening HbA1C between 7.5% and 11.0%
• is a male, or a female who is highly unlikely to conceive during the study and for 14 days after the last dose of study medication

Exclusion Criteria:

• has a history of type 1 diabetes mellitus or a history of ketoacidosis
• has been treated with any antihyperglycemic therapies other than a sulfonylurea (alone or with metformin) within the prior 12 weeks or has ever

been treated with a dipeptidyl peptidase-4 inhibitor or a glucagon-like peptide-1 mimetic or analogue

• has a history of intolerance or hypersensitivity, or has any contraindication to sitagliptin, gliclazide/glimepiride, or metformin
• is on a weight loss program and not in the maintenance phase, or has started a weight loss medication or has undergone bariatric surgery within 12 months
• has undergone a surgical procedure within 4 weeks or has planned major surgery during the study
• has a medical history of active liver disease
• has had new or worsening signs or symptoms of coronary heart disease within the past 3 months, or has acute coronary syndrome, coronary artery intervention, or stroke or transient ischemic neurological disorder
• has a diagnosis of congestive heart failure with New York Heart Association Class III - IV cardiac status
• has a systolic blood pressure ≥ 160 mmHg or a diastolic blood pressure ≥ 90 mmHg
• has human immunodeficiency virus (HIV)
• has severe peripheral vascular disease
• is currently being treated for hyperthyroidism or is on thyroid hormone therapy and has not been on a stable dose for at least 6 weeks
• has a history of malignancy ≤ 5 years before the study, except for adequately treated basal cell or squamous cell skin cancer, or in situ cervical cancer
• has a clinically important hematological disorder (such as aplastic anemia,

myeloproliferative or myelodysplastic syndromes, thrombocytopenia)

• is pregnant or breast feeding, or is expecting to conceive or donate eggs during the study, including 14 days after the last dose of study medication
• is a user of recreational or illicit drugs or has had a recent history of drug abuse