Safety and Efficacy of LX4211 With Metformin in Type 2 Diabetes Patients With Inadequate Glycemic Control on Metformin

Inclusion Criteria: * Adult subjects between the ages of 18 to 75 years, inclusive * Confirmed diagnosis of Type 2 diabetes mellitus * Meet required laboratory values at screening, including fasting plasma glucose less than 270 mg/dL * Stable dose of metformin monotherapy greater than 1500 mg/day for at least 8 weeks * Willing and able to provide written informed consent * Willing and able to maintain consistent dietary, physical activity, and sleeping patterns throughout the study Exclusion Criteria: * History of Type 1 diabetes mellitus, diabetic ketoacidosis, hyperosmolar nonketotic syndrome, or diabetes resulting from pancreatic disorder or secondary diabetes * History of renal disease or clinically significant abnormal kidney function tests * Presence of active hepatic disease or clinically significant abnormal liver function tests * Subjects with a history of heart attack, severe/unstable angina, or coronary revascularization procedure within 6 months prior to study Day 1 * History of clinically significant cardiac arrhythmias within one year of study Day 1 * Subjects with congestive heart failure * Subjects with uncontrolled Stage III hypertension * Triglycerides \>1000 mg/dL at Screening * Known history of HIV or hepatitis C * History of illicit drug or alcohol abuse with one year of study Day 1 * Have had 2 or more emergency room visits, doctor visits, or hospitalizations due to hypoglycemia within 6 months of study Day 1 * Use of any other investigational drug within 30 days of study Day 1 * Prior exposure to LX4211 * Use of any medication or herbal supplement for the purpose of weight loss * Chronic use of any antidiabetic therapy other than metformin in the 3 months prior to study Day 1 * Use of corticosteroids within 2 weeks prior to study Day 1 * Major surgery within 6 months of study Day 1 * Subjects with any history of severe gastroparesis * Inability or difficulty swallowing whole capsules or tablets * Women who are pregnant or breast feeding