Efficacy and safety of dapagliflozin over 1 year as add-on to insulin therapy in Japanese patients with type 2 diabetes: the DAISY (Dapagliflozin Added to patients under InSulin therapY) trial.

AIMS: To evaluate the efficacy and safety of dapagliflozin as add-on to insulin in Japanese patients with type 2 diabetes.

MATERIALS AND METHODS: Insulin-treated Japanese patients were randomized to 5 mg dapagliflozin or placebo during a 16-week double-blind treatment period. Both groups then received dapagliflozin 5 or 10 mg (the dose was increased at or after week 24 if glycated haemoglobin [HbA1c] at the previous visit was >7.5%) during a 36-week open-label extension period. The exploratory efficacy endpoint was to assess the maintenance efficacy of 5/10 mg dapagliflozin + insulin over 52 weeks of treatment. Safety was assessed in terms of adverse events, laboratory variables and vital signs.

RESULTS: The changes in HbA1c from baseline to weeks 16 and 52 were -0.62% and -0.74%, respectively, in the dapagliflozin group, vs -0.08% and -0.83%, respectively, in the placebo-dapagliflozin group. Body weight decreased at both time points in the dapagliflozin group and after switching to open-label dapagliflozin in the placebo-dapagliflozin group. The total insulin dose decreased slightly after starting dapagliflozin. Adverse events occurred in 82.9% and 71.7% of patients in the dapagliflozin and placebo-dapagliflozin groups, respectively. Hypoglycaemia occurred in 35.0% and 41.7% of patients in the dapagliflozin and placebo-dapagliflozin groups, respectively, but the incidence was not increased by use of dapagliflozin in either trial period. Genital/urinary tract infections, renal impairment/failure, volume depletion, fracture and hepatic disorders occurred in ≤5% of patients.

CONCLUSION: This trial showed that administration of dapagliflozin as an add-on to insulin therapy was effective, was well tolerated and had insulin-sparing effects in Japanese patients with type 2 diabetes.