['type 1 diabetes mellitus']
['sotagliflozin', 'placebo']

        Inclusion Criteria:

          -  Participant had given written informed consent.

          -  Young adult participants >=18 to <=30 years old at Screening, with a confirmed
             diagnosis of T1DM made at least 1 year prior to informed consent.

          -  Participants were being treated with insulin or insulin analogue delivered via
             continuous subcutaneous insulin infusion (CSII) or multiple daily injections (MDI).

          -  At Screening, must had A1C >= 9.0%.

          -  Must be willing and able to perform self-monitored blood glucose (SMBG) and complete
             the study diary.

          -  Females of childbearing potential must use an adequate method of contraception and had
             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 sodium-glucose cotransporter (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 diabetic ketoacidosis (DKA) or nonketotic hyperosmolar state within 6
             months prior to the Screening Visit.

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