This is a randomized (the study medication is assigned by chance), double-blind (neither physician nor participant knows the identity of the assigned treatment), placebo-controlled (an inactive substance that is compared with a medication to test whether the medication has a real effect) parallel-group, multicenter study of canagliflozin as an addition to insulin therapy for participants with type 1 diabetes mellitus and inadequate glycemic control.
Approximately 330 participants will be randomly assigned in a 1:1:1 ratio to either canagliflozin 100 mg, canagliflozin 300 mg, or placebo groups. About 90 participants (30 per treatment group) will be selected for a substudy with a purpose of a continuous glucose monitoring (CGM) assessment for 7 days at baseline and 7 days at the end of treatment.
The total duration of the participation will be about 22 weeks, during which participants will need to return to investigational sites for approximately 9 visits. During the study participants will receive advice on treatment of hypoglycemia and diabetic ketoacidosis (DKA), as well as on compliance with diet and exercise.