Efficacy and safety of dapagliflozin in addition to insulin therapy in Japanese patients with type 2 diabetes: Results of the interim analysis of 16‐week double‐blind treatment period

Introduction Dapagliflozintreatment when added to insulin therapy in Japanese patients with type 2 diabetes remains to be evaluated. Materials and Methods This was a multicenter, randomized, double-blind, parallel-group, placebo-controlled studyto evaluate efficacy (at 16 weeks) and long-term safety (at 52 weeks) of dapagliflozinin addition to insulin therapy. The interim analysiswas carried out at week 16 to assess the efficacy and safety profiles. The patients receiving insulin (n = 182) were randomized to either dapagliflozin5 mg or a placeboat a 2:1 ratio. The primary efficacy end-point was the change in hemoglobin A1c (HbA1c) from baseline at week 16. Results Patients in the dapagliflozingroup showed an adjusted decrease in HbA1c of −0.55% from baseline, whereas the placeboshowed a marginal increase of 0.05%. The placebo-corrected mean change of HbA1c from baseline to week 16 in dapagliflozinwas −0.60% (P < 0.0001). In addition, the placebo-corrected mean change of fasting plasma glucose and bodyweight from baseline to week 16 in the dapagliflozingroup was −22.7 mg/dL (P < 0.0001) and −1.21 kg (P < 0.0001), respectively. The placebo-corrected mean daily insulin dose in the dapagliflozingroup was numerically decreased (treatment difference: −0.72 IU/day; P = 0.0743). No major episodes or discontinuations as a result of hypoglycemia were reported during the study period. Conclusions Dapagliflozinused as add-on treatment to insulin therapy showed significantly greater reduction of HbA1c, fasting plasma glucose and bodyweight without severe hypoglycemia compared with the placeboat week 16. These results show the clinical benefit of prescribing dapagliflozinfor Japanese patients with insufficient glycemic control even with insulin therapy.