Efficacy and Tolerability of Linagliptin Added to a Sulfonylurea Regimen in Patients With Inadequately Controlled Type 2 Diabetes Mellitus: An 18-Week, Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial

Background: Some patients with type 2 diabetes mellitus (T2DM) receiving monotherapy with a sulfonylurea (SU) are unable to meet recommended glycemic targets over the long term and require additional pharmacologic agents to maintain glycemic control. This study was designed to assess the utility of adjunctive therapy with the dipeptidyl peptidase (DPP)-4 inhibitor linagliptin in patients with T2DM inadequately controlled with SU monotherapy. Objective: To assess the efficacy and tolerability of linagliptin as add-on therapy in patients with inadequately controlled T2DM despite background therapy with an SU. Methods: In this Phase III, multicenter, randomized, double-blind, placebo-controlled trial, patients with inadequately controlled T2DM on SU monotherapy were randomly assigned to receive treatment with linagliptin 5 mg once daily (n = 161) or placebo (n = 84) for 18 weeks. The primary end point was the mean change in hemoglobin (Hb) A(1c) from baseline to week 18, evaluated using ANCOVA. Tolerability was assessed using laboratory analysis, spontaneous reporting, and physical examination and interview. Results: Mean baseline characteristics were similar in the linagliptin and placebo groups. Linagliptin treatment was associated with a placebo-corrected mean (95% CI) change in HbA(1c) from baseline (8.6%) to 18 weeks of -0.47% (-0.70 to -0.24; P < 0.0001). Patients in the linagliptin group were more likely compared with placebo to achieve the HbA(1c) target level of <7.0% after 18 weeks of treatment (15.2% vs 3.7%, respectively; odds ratio [OR] = 6.5; 95% CI, 1.7-24.8; P = 0.007). Similarly, patients in the linagliptin group were more likely to achieve an HbA(1c) reduction of >= 0.5% compared with those in the placebo group (57.6% vs 22.0%; OR = 5.1, 95% CI 2.7-9.6; P < 0.0001). The overall frequency of adverse events was similar between the linagliptin and placebo groups (42.2% vs 42.9%). The incidences of hypoglycemic events were not significantly different between the 2 groups (5.6% vs 4.8%), and none of the hypoglycemic episodes were assessed as severe by the investigator. The difference in the changes in mean body weight was not significant (+0.43 vs -0.01 kg; P = 0.12). Conclusions: The addition of linagliptin to SU therapy for 18 weeks in these patients with T2DM was associated with statistically significant and clinically meaningful reductions in HbA(1c) compared with placebo. The overall tolerability of linagliptin was similar to that of placebo, with a low risk for hypoglycemia and no significant weight gain. These findings support the use of linagliptin as adjunctive therapy in patients with T2DM inadequately controlled on SU monotherapy. ClinicalTrials.gov identifier: NCT00819091. (Clin Ther. 2012;34:1909-1919) (C) 2012 Elsevier HS Journals, Inc. All rights reserved.