Exploring the Substitution of Exenatide for Insulin in Patients with Type 2 Diabetes Treated with Insulin in Combination with Oral Antidiabetic Agents

Abstract

Objective: This 16-week study explored the safety of substituting exenatide for insulin in patients with type 2 diabetes using insulin in combination with oral antidiabetic agents.

Research Design and Methods: Successful maintenance of glycemic control was predefined as an HbA_1c increase of less than 0.5%. Forty-nine patients (age 53 ± 8 y, BMI 34 ± 4 kg/m², HbA_1c 8.1 ± 1.1%, duration of diabetes 11 ± 7 y) were randomized to either substitute exenatide for insulin or remain on their current insulin regimen. Patients who either completed ≥8 weeks of study or discontinued due to loss of glycemic control were included in primary efficacy analysis.

Results: Sixty-two % (18/29) of the exenatide-treated patients maintained glycemic control compared with 81% (13/16) of the insulin-treated patients. Of the 11 exenatide-treated patients who did not maintain control, 5 patients discontinued before Week 16 due to loss of glucose control. The overall safety profile was generally consistent with previous exenatide trials. The mean overall hypoglycemia rates were 1.72 and 0.97 events/patient-year for the exenatide and insulin reference group, respectively.

Conclusion: This pilot study suggests that it is feasible to sustain glycemic control when substituting exenatide for insulin. Although it is not possible to characterize clear predictors of outcome given the size and exploratory nature of the study, the data suggest that patients with longer disease duration, who are taking higher doses of insulin and have less endogenous beta cell function, may experience deterioration in glucose control if exenatide is substituted for insulin therapy.