A Study to Evaluate the Pharmacodynamic Effects of Single-Dose Co-Administration of LX4211 With Januvia® in Type 2 Diabetics

Inclusion Criteria: * Adults aged 18 to 65 years of age * History of Type 2 Diabetes Mellitus for at least 3 months prior to Screening, with HgbA1c values of 6.5 to 10.5% and C-peptide ≥1.0 ng/mL * Body mass index (BMI) ≤45 kg/sq m * Willing and able to self-monitor blood glucose * Able to provide written informed consent Exclusion Criteria: * History of Type 1 diabetes mellitus, diabetic ketoacidosis, hyperosmolar nonketotic syndrome, or diabetes resulting from pancreatic disorder or secondary diabetes * Current use of any blood glucose lowering agent other than metformin * History of renal disease or clinically significant abnormal kidney function tests at Screening or Day -2 * Presence of active hepatic disease or clinically significant abnormal liver function tests at Screening or Day -2 * History of myocardial infarction, severe/unstable angina, or coronary revascularization procedure within 6 months of Day -2 * History of clinically significant cardiac arrhythmias within 1 year of Day -2 * Congestive heart failure and/or New York Heart Association (NYHA) class III or IV symptoms of heart failure * Subjects with uncontrolled Stage 3 hypertension * History of 2 or more emergency room visits, doctor's visits, or hospitalizations due to hypoglycemia within 6 months of Day -2 * History of alcohol or drug abuse within 12 months of Screening * History of bowel resection \> 20 cm, any malabsorptive disorder, severe gastroparesis, and GI procedure for the purpose of weight loss that would slow gastric emptying * History of HIV or hepatitis C * Major surgery within 3 months of Day -2 or any planned surgery during the study * History of any active infection within 2 weeks of Day -2 * History of pancreatitis * History of any malignancy within the last 5 years which would affect the diagnosis or assessment of LX4211 or sitagliptin * History of any serious adverse reaction or hypersensitivity to LX4211 or sitagliptin * Presence of any clinically significant physical, laboratory, or ECG findings or any concurrent condition at Screening that may interfere with the study in the opinion of the investigator * Triglycerides \> 1000 mg/dL at Screening or Day -2 * Donation or loss of \>400 mL of blood or blood product within 8 weeks prior to Day -2 * Use of any tobacco product for the duration of study participation * Use of corticosteroids within 2 weeks of Day 1 * Use of digoxin or warfarin within 2 weeks prior to Screening