Meta-Analysis of Exenatide, the Sitagliptin, and Pramlintide Compared to Placebo for Treatment of Type II Diabetes.

Abstract

OBJECTIVES: To evaluate glycemic control, therapy associated weight loss/gain, and hypoglycemic events for the newer type 2 diabetic agents pramlintide, exenatide, and sitagliptin. METHODS: The meta-analysis examined the efficacy of three currently FDA approved peptide analogues in nonpregnant adults with type 2 diabetes mellitus. All randomized, placebo controlled trials of exenatide, pramlintide, and sitagliptin that were indexed in MEDLINE or and the Cochrane Database of Systematic Reviews that fit the inclusion criteria were included. The drug treatment efficacy was analyzed in terms of HbA1c (glycosylated hemoglobin) change from baseline compared to placebo in trials lasting at least 12 weeks. Weight change from baseline per treatment group was also a primary measure. The safety of the treatments was assessed in terms of number of hypoglycemic events noted in the clinical trials. Each of these dependent variables was assessed separately for the three products. RESULTS: The meta-analysis of the six exenatide articles included in the analysis found statistically significant reductions in both HbA1c and weight when compared to placebo. However, patients were three times as likely to experience hypoglycemia with exenatide than placebo (RR= 3.01 95%CI[0.427 to 3.865]). Meta-analysis of pramlintide studies showed statistically significant lowering of HbA1c and weight. Overall pramlintide resulted in a rate of hypoglycemia nearly equal to that of placebo (RR= 0.94 95%CI[0.699 to 1.265]). Meta-analysis of sitagliptin found statistically significant reductions in HbA1c compared to placebo. However, sitagliptin use was not associated with a reduction in weight in the random effects meta-analysis model. In terms of hypoglycemic events, sitagliptin use was associated with 2.89 times greater risk of causing hypoglycemic episodes compared to placebo (RR=2.89 95%CI[0.704 to 5.877]). CONCLUSIONS: All three newer products were associated with improved glycemic control compared to placebo. Improvement in weight was associated with exenatide and pramlintide treatment. Pramlintide was not associated with an increase in hypoglycemic episodes.