A randomized, placebo-controlled trial to assess the efficacy and safety of sitagliptin in Japanese patients with type 2 diabetes and inadequate glycaemic control on ipragliflozin

Aims: To investigate the efficacy, safety and tolerability of sitagliptin 50 mg once daily added to ipragliflozin 50 mg once daily monotherapy in Japanese patients with type 2 diabetes (T2D).

Materials and methods: Japanese patients with T2D and glycated haemoglobin (HbA1c) 7.0% to 10.0% while treated with ipragliflozin 50 mg once daily were randomized 1:1 to additional treatment with sitagliptin 50 mg once daily (N = 70) or matching placebo (N = 71) for 24 weeks. The primary efficacy endpoint was change in HbA1c at Week 24. Secondary efficacy endpoints were changes in 2-hour post-meal glucose (PMG), total PMG 0- to 2-hour area under the curve (AUC_0-2h ), and fasting plasma glucose (FPG).

Results: Baseline characteristics were similar in the two groups (mean age 55.5 years, mean baseline HbA1c 8.0%). After 24 weeks, the addition of sitagliptin provided significantly greater reduction in HbA1c compared to placebo (least squares [LS] mean difference -0.83% [95% confidence interval -1.05, -0.62]; P <0.001). Significant reductions were also observed in all secondary endpoints: LS mean differences from placebo in changes in 2-hour PMG, total PMG AUC_0-2h , and FPG were -42.5 mg/dL, -67.0 mg·h/dL and -11.2 mg/dL, respectively (all P <0.001). The incidence of adverse events (AEs) overall and incidence of predefined AEs of clinical interest (symptomatic hypoglycaemia, urinary tract infection, genital infection, hypovolaemia and polyuria/pollakiuria) were similar in the two groups.

Conclusions: In Japanese patients with T2D, sitagliptin 50 mg once daily added to ipragliflozin 50 mg once daily monotherapy provided significant improvement in glycaemic control and was generally well tolerated. ClinicalTrials.gov: NCT02577016.