Empagliflozin as adjunct to insulin in Japanese participants with type 1 diabetes: Results of a 4-week, double-blind, randomized, placebo-controlled phase 2 trial

Aims: This phase 2, double-blind, randomized, placebo-controlled trial (ClinicalTrials.gov NCT02702011) with 4 sites in Japan investigated the pharmacodynamics (PD), pharmacokinetics (PK) and safety profile of empagliflozin in Japanese participants with type 1 diabetes mellitus (T1DM) as adjunctive therapy to insulin. Materials and methods: Participants using multiple daily injections of insulin for >= 12 months, with HbA1c of 7.5%-10.0%, entered a 2-week, open-label, placebo run-in period, followed by a 4-week, double-blind period during which participants were randomized 1:1:1:1 to receive empagliflozin 2.5 mg (n = 13), empagliflozin 10 mg (n = 12), empagliflozin 25 mg (n = 12) or placebo (n = 11). The primary objective was to assess the effect of empagliflozin vs placebo on urinary glucose excretion (UGE) after 7 days of treatment. Results: PD: Empagliflozin resulted in a dose-dependent significant increase in 24-hour UGE compared with placebo (UGE placebo-corrected mean [95% confidence interval] change from baseline: 2.5 mg, 65.10 [43.29, 86.90] g/24 h; 10 mg, 81.19 [58.80, 103.58] g/24 h; 25 mg, 98.11 [75.91, 120.31] g/24 h). After 4 weeks of treatment, UGE increase was associated with improved glycaemic control, reduced body weight and decreased insulin needs. Empagliflozin treatment also resulted in dose-dependent increases in serum ketone bodies and free fatty acids. PK: Plasma empagliflozin levels increased in a dose-dependent manner and peaked at 1.5 hours. In this short study, empagliflozin was well tolerated, with no increase in rate of hypoglycaemia and no diabetic ketoacidosis events reported. Conclusions: Based on this short-duration phase 2 study, the PK/PD profile of empagliflozin in Japanese participants with T1DM is comparable to that of non-Japanese participants.