Combination Therapy with Insulin Glargine and Exenatide: Real-world Outcomes in Patients with Type 2 Diabetes

Objective: To investigate the real-world use of combination insulin glargine/exenatide therapy for type 2 diabetes mellitus (T2DM) and associated treatment persistence and glycemic control.

Methods: In this retrospective study, data were extracted from a national US insurance claims database for patients with T2DM for whom insulin glargine and exenatide were co-prescribed in differing order: insulin glargine added after exenatide (EXE+); exenatide added after insulin glargine (GLA+); glargine and exenatide initiated together (GLA + EXE). Patients had continuous health plan coverage for 6 months pre- (baseline) and 1-year post-index (follow-up).

Results: A total of 453 patients were eligible for analysis: 141 patients were included in the EXE+ cohort, 281 in the GLA+ cohort, and 31 in the GLA + EXE cohort. There were significant differences between the groups at baseline, including a significantly lower A1C in the GLA+ versus the EXE+ cohort (p = 0.0023). Around one third of patients stayed on both drugs up until the end of the follow-up period (GLA+: 30.2%; EXE+: 29.0%; GLA + EXE: 29.0%). However, more patients stayed on insulin glargine than on exenatide in each cohort. Significant A1C reductions were observed in each of the cohorts at follow-up: GLA+: -0.4%; EXE+: -0.9%; GLA + EXE: -1.2%; p < 0.01, and were significantly higher in the GLA + EXE and EXE+ cohorts than in the GLA+ cohort (p = 0.03 and p = 0.002, respectively). The mean number of hypoglycemic events increased slightly from baseline but remained low in each of the cohorts (GLA+: 0.12 to 1.42; EXE+: 0.09 to 1.04; GLA + EXE: 0.23 to 1.87 per patient, all p > 0.1).

Conclusions: Combined therapy with insulin glargine and exenatide resulted in A1C reductions in T2DM patients with poor glycemic control without a significantly increased risk of hypoglycemia irrespective of treatment order. Limitations of this study are the between-cohort differences at baseline, lack of a comparator group, and small n number, particularly in the GLA + EXE cohort.