TitleEfficacy and safety of meal-time administration of short-acting exenatide for glycaemic control in type 1 diabetes (MAG1C): a randomised, double-blind, placebo-controlled trial
BACKGROUND In type 2 diabetes, long-acting GLP-1 receptor agonists lower fasting plasma glucose and improve glycaemic control via their insulinotropic and glucagonostatic effects. In type 1 diabetes, their efficacy as an add-on treatment to insulin therapy is modest. Short-acting GLP-1 receptor agonists also lower postprandial glucose excursions in type 2 diabetes by decelerating gastric emptying rate. We aimed to test the efficacy of a short-acting GLP-1 receptor agonist in type 1 diabetes.
METHODS In the single-centre, parallel-group, randomised, double-blind, placebo-controlled MAG1C trial, patients with type 1 diabetes on multiple daily injection therapy aged 18 years and older with HbA 1c 59-88 mmol/mol (7·5-10·0%) and a BMI of more than 22·0 kg/m 2 were randomly assigned (1:1) through a computer-generated randomisation list to preprandial subcutaneous injection of 10 μg exenatide (Byetta) or placebo three times daily for 26 weeks as an add-on treatment to usual insulin therapy. Clinically assessed insulin titration was done by study staff. Participants and investigators were masked to treatment allocation. The primary endpoint was between-group difference in HbA 1c after 26 weeks. Data were analysed with a baseline-adjusted linear mixed model in the intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT03017352, and is completed.
FINDINGS Between Jan 4, 2017, and Jan 16, 2019, 108 participants were randomly assigned, 54 to exenatide and 54 to placebo; 23 participants discontinued treatment (17 in the exenatide group and six in the placebo group). From a baseline-adjusted mean of 66·4 mmol/mol (95% CI 64·9-67·8 [8·2%, 8·1-8·4]), HbA 1c changed by -3·2 mmol/mol (-5·0 to -1·4 [-0·3%, -0·5 to -0·1]) with exenatide and -2·1 mmol/mol (-3·7 to -0·6 [-0·2%, -0·3 to -0·1]) with placebo after 26 weeks (estimated treatment difference of -1·1 mmol/mol (-3·4 to 1·2 [-0·1%, -0·3 to 0·1]; p=0·36). Exenatide increased the number of self-reported gastrointestinal adverse events (primarily nausea [48 events among 37 patients with exenatide, nine with placebo among 9 patients]). Two serious adverse events occurred in the exenatide group, and six occurred in the placebo group (none were considered to be related to the study drug).
INTERPRETATION Short-acting exenatide does not seem to have a future as a standard add-on treatment to insulin therapy in type 1 diabetes.