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 study drug, to test whether the study drug has a real effect), multicenter study of efficacy, safety, and tolerability of canagliflozin in participants with T2DM, who have inadequate glycemic (blood sugar) control on maximally or near-maximally effective doses of metformin >=1500 mg/day and sitagliptin 100 mg/day. Approximately 200 participants will be randomly assigned to 1 of 2 treatment groups in 1:1 ratio for 26 weeks. During the study the participants will be also provided with diet and exercise counseling (standardized non-pharmacological therapy).