Efficacy and Safety of Sotagliflozin in Young Adult Patients With Type 1 Diabetes Mellitus and Elevated Hemoglobin A1C

Inclusion Criteria:

- Patient has given written informed consent

- Young adult patients ≥18 to ≤30 years old at Screening, with a confirmed diagnosis of
T1DM made at least 1 year prior to informed consent

- Patients are being treated with insulin or insulin analogue delivered via CSII or MDI

- At Screening, must have A1C ≥9.0%

- Must be willing and able to perform SMBG and complete the study diary

- Females of childbearing potential must use an adequate method of contraception and
have a negative pregnancy test

Exclusion Criteria:

- Any prior use of LX4211/Sotagliflozin

- Use of antidiabetic agent other than insulin or insulin analogue at the time of
screening

- Use of SGLT inhibitors within 8 weeks prior to start of the placebo Run-in Period

- Chronic systemic corticosteroid use

- Type 2 diabetes, or severely uncontrolled diabetes mellitus as determined by the
Investigator

- History of DKA or nonketotic hyperosmolar state within 6 months prior to the Screening
Visit

- History of severe hypoglycemic event within 1 month prior to Screening Visit