Safety and Efficacy Assessment of a GLP-1 Mimetic: Insulin Glargine Combination for Treatment of Feline Diabetes Mellitus

A commonly used therapeutic strategy for type 2 diabetes mellitus (DM) in humans involves the use of synthetic incretin hormone-based therapies including exenatide, a glucagon-like pepetide-1 hormone agonist. Glucagon-like pepetide-1 agonists can be used alone or as an ancillary therapy with other agents, including insulin and oral antihyperglycemics. Little is known about the role of these therapies for DM in cats. Therefore, the primary objective of this study was to evaluate the safety and efficacy of short-acting exenatide combined with insulin, as compared to placebo and insulin for the treatment of DM in cats. Treatment with exenatide was well tolerated; only 2 cats developed side effects requiring dose reduction. Two cats (25%) went into diabetic remission while receiving exenatide and insulin, whereas remission was not reported during placebo treatment. The average change in the daily exogenous insulin dose was significant (β = -0.56 U/kg, 95% confidence interval, -0.96 to -0.15, P = 0.007), and the dose of insulin administered was lower during exenatide treatment. The average weight loss experienced on exenatide was significantly higher than on placebo (β = 0.65 kg, 95% confidence interval, 0.09-1.21, P = 0.02). There was no significant difference in any of the hormone concentrations evaluated for cats on exenatide vs placebo treatments. Overall, the treatment of diabetic cats with insulin and a fixed dose of exenatide was found to be safe. The weight loss and decreased exogenous insulin requirement experienced with exenatide treatment could be a significant benefit for overweight diabetic cats and warrants further evaluation.