Addition of sitagliptin to ongoing glimepiride therapy in Japanese patients with type 2 diabetes over 52 weeks leads to improved glycemic control

The efficacy and safety of sitagliptin as an add-on therapy to glimepiride were evaluated in a multicenter, randomized, double-blind, placebo-controlled study, followed by an uncontrolled open-label period, in Japanese patients with type 2 diabetes who had inadequate glycemic control on diet/exercise therapy and glimepiride monotherapy. During the initial double-blind period, sitagliptin (50 mg q.d.) or placebo was added to ongoing glimepiride [1–6 mg a day] for 12 weeks. This was followed by a 40-week period of open-label administration of sitagliptin 50 (or 100 mg q.d. after up-titration) added to continued glimepiride. For the placebo-controlled, 12-week double-blind period, the difference between the two treatment groups in the least-squares mean change from baseline and its 95% confidence interval (CI) for HbA1c was −0.76% (−0.98, −0.55, p < 0.001) in favor of the addition of sitagliptin. The mean changes from baseline in 2-h post-meal glucose and fasting plasma glucose were significantly lower in the sitagliptin group compared with the placebo group: −43.2 mg/dL (−58.9, −27.5) and −18.1 mg/dL (−25.7, −10.5), respectively (both p < 0.001). During the initial 12 weeks, the incidence of adverse experiences was similar in both treatment groups with comparable, low incidences of hypoglycemia and no differences in weight change between groups. The glycemic changes from baseline following the addition of sitagliptin to glimepiride remained generally stable through 52 weeks. The addition of sitagliptin improved glycemic parameters including HbA1c and was generally well tolerated through 52 weeks in Japanese patients with type 2 diabetes who had inadequate glycemic control with diet/exercise and glimepiride monotherapy.