Objective: To evaluate the 1-year efficacy and safety of treatment with exenatide in combination with insulin (a use not approved by the US Food and Drug Administration).
Methods: Electronic medical records of 3 private-practice endocrinologists were reviewed to identify patients with type 2 diabetes mellitus (T2DM) receiving insulin who subsequently began exenatide therapy. Patients' baseline hemoglobin A1c (A1C) levels, weights, lipid profiles, blood pressures, and medication utilization were compared with corresponding data obtained after a minimal duration of 12 months.
Results: We identified 134 patients with T2DM initiating exenatide therapy in combination with insulin between April 2005 and April 2006. One-year follow-up information was available for 124 patients. Exenatide use resulted in a significant 0.87% reduction in A1C (P<.001), despite a 45% discontinuation of premeal insulin use (P<.001), a 9-U reduction in mean premeal insulin doses (P = .0066), a reduction in the median number of daily insulin injections from 2 to 1 (P = .0053), and a 59% discontinuation rate of sulfonylurea use (P = .0088). Exenatide use was associated with a mean weight loss of 5.2 kg (P<.001), with 72% of evaluable patients losing weight. Forty-eight patients (36%) discontinued exenatide therapy during the first year, primarily attributable to gastrointestinal intolerance. Fourteen patients (10%) experienced hypoglycemia, most of which was mild.
Conclusion: Exenatide in combination with insulin in patients with T2DM was associated with significant reductions in A1C and weight after 1 year of therapy. This was offset, however, by an exenatide discontinuation rate of 36%, primarily due to adverse gastrointestinal effects.