Pharmacokinetics and pharmacodynamics of dapagliflozin in combination with insulin in Japanese patients with type 1 diabetes.

Aims: To assess the pharmacokinetics/pharmacodynamics (PK/PD) of dapagliflozin, a sodium-glucose co-transporter 2 inhibitor that increases urinary glucose excretion (UGE) and its major metabolite, dapagliflozin-3-O-glucuronide (D3OG), in Japanese patients with type 1 diabetes (T1D) and inadequate glycaemic control (HbA1c 7%-10%).
Materials and Methods: Japanese patients (18-65 years) with inadequately controlled T1D were randomized 1:1:1 to dapagliflozin 5 mg, 10 mg or placebo (n = 14 each) once daily for 7 days, with adjustable insulin. The PK/PD characteristics of dapagliflozin and D3OG were assessed on Day 7. Patients underwent follow-up evaluation on Days 8 and 14. Adverse events (AEs), hypoglycaemic episodes and events of diabetic ketoacidosis (DKA) were recorded over the treatment and follow-up periods.
Results: A total of 42 randomized patients received dapagliflozin or placebo. PK variables increased in a dose-dependent manner. D3OG was generated rapidly, with a median time to maximum plasma concentration of 2.0 hours (1.0-3.0). The dapagliflozin dose-UGE relationship was attenuated, with larger insulin dose reductions than anticipated. Mean percent (standard error) changes in total daily insulin dose from baseline to Day 7 were - 36.86% (3.32), -39.13% (2.68) and - 4.97% (5.28) for dapagliflozin 5 mg and 10 mg and for placebo, respectively. No DKA was reported. AEs were consistent with the established dapagliflozin safety profile. There was no increase in hypoglycaemia.
Conclusions: The PK and safety profiles of dapagliflozin in Japanese patients with T1D were consistent with previous studies, but with an unanticipated attenuation of the PD dose-response measured as UGE.
(© 2018 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.)