Abstract
AIMS: To investigate the safety and tolerability of 5 and 10 mg dapagliflozin added to insulin therapy over 52 weeks in Japanese patients with inadequately controlled type 1 diabetes mellitus (T1DM). MATERIALS AND METHODS: This randomized, open-label, parallel-group, multicentre phase III clinical trial was conducted from October 26, 2015 to June 15, 2017. The primary endpoint was the occurrence of adverse events such as hypoglycaemia and diabetic ketoacidosis. Secondary endpoints included changes in glycaemic parameters, total daily insulin dosage and body weight over time. The efficacy of dapagliflozin in patients stratified by body mass index (BMI) <25.0 and ≥25.0 kg/m(2) was evaluated in a subgroup analysis. RESULTS: In total, 151 patients received 5 mg (n = 76) or 10 mg (n = 75) dapagliflozin once daily for 52 weeks. Adverse events were observed in 88.2% and 73.3% of patients in the 5 and 10 mg dapagliflozin groups, respectively. Severe hypoglycaemia was reported in 2.6% (n = 2) and 6.7% (n = 5) of patients, and diabetic ketoacidosis in 2.6% (n = 2) and 1.3% (n = 1) of patients in the 5 and 10 mg dapagliflozin groups, respectively. The adjusted mean (95% confidence interval) changes in glycated haemoglobin at week 52 were -0.33% (-0.50, -0.15) and -0.36% (-0.53, -0.18) in the 5 and 10 mg dapagliflozin groups, respectively. There were no differences in efficacy parameters when stratified by BMI. CONCLUSIONS: This study demonstrated the long-term safety and tolerability of dapagliflozin added to insulin therapy in Japanese patients with inadequately controlled T1DM.