Efficacy and safety of saxagliptin in combination with insulin in Japanese patients with type 2 diabetes mellitus: a 16-week double-blind randomized controlled trial with a 36-week open-label extension.

Background: We examined the efficacy and safety of saxagliptin as an add-on to insulin in Japanese patients with type 2 diabetes mellitus.
Research Design and Methods: We randomized 240 patients with type 2 diabetes mellitus on insulin monotherapy to 5-mg saxagliptin or placebo as add-on therapy for a 16-week, double-blind period. All patients received 5-mg saxagliptin and insulin for an additional 36 weeks (open-label extension). Change in hemoglobin A1c (HbA1c) at Week 16 was the main endpoint.
Results: At Week 16, the adjusted change in HbA1c from baseline increased by 0.51% with placebo and decreased by 0.40% with saxagliptin (difference -0.92% [95% confidence interval -1.07%, -0.76%; p < 0.001]). In patients receiving saxagliptin, reductions in HbA1c at Week 16 were maintained to Week 52, while switching from placebo to saxagliptin resulted in a similar reduction in HbA1c. The incidence of hypoglycemia was not markedly increased with saxagliptin versus placebo in the double-blind period and did not increase substantially during the open-label extension period. The efficacy and safety of saxagliptin was similar between the elderly and non-elderly patient groups.
Conclusions: Adding saxagliptin to ongoing insulin therapy improved glycemic control and was well tolerated in Japanese patients with type 2 diabetes.