Patient preference and tolerability of a DPP-4 inhibitor a GLP-1 analog in patients with type 2 diabetes mellitus inadequately controlled with metformin: a 24-week, randomized, multicenter, crossover study

Objective: The present study aimed to assess the patient preference and tolerability of oral dipeptidyl peptidase-4 inhibitor (vildagliptin) versus injectable glucagon-like peptide-1 analog (liraglutide) in patients with type 2 diabetes mellitus inadequately controlled with metformin monotherapy. Methods: This 24-week, randomized, multicenter, crossover study, patients with type 2 diabetes mellitus inadequately controlled on metformin monotherapy with hemoglobin A1c (HbA 1c ) ⩾6.5% and ⩽9.0% were randomized in a crossover manner to receive either vildagliptin/metformin single-pill combination (SPC) 50/1000 mg twice daily ( n = 32) or 1.2 mg liraglutide as an add-on to metformin (0.6 mg [weeks 0–1] followed by 1.2 mg [weeks 2–12] once daily/1000 mg twice daily) ( n = 30) for the first 12 weeks. Results: Patient preference at week 24 was similar, with 51.7% ( n = 31) patients preferring vildagliptin/metformin SPC compared with 48.3% ( n = 29) preferring liraglutide as an add-on to metformin therapy ( p = 0.449). Post hoc analyses showed that more elderly patients (⩾65 years) preferred vildagliptin (65%; n = 13) over liraglutide (35%; n = 7) therapy. Liraglutide was associated with better improvement in fasting plasma glucose (–21.5 mg/dl versus –3.4 mg/dl) and HbA 1c (–0.5% versus –0.3%) levels. Fewer adverse events were reported with vildagliptin/metformin SPC ( n = 16) compared with liraglutide as add-on to metformin treatment ( n = 46). Conclusions: In this pilot study, although both vildagliptin and liraglutide therapies were preferred similarly by the patients and showed effective control of glycemia over 12 weeks, vildagliptin was associated with fewer adverse events and was preferred more by elderly patients