Efficacy and Safety of Linagliptin Co-Administered with Low-Dose Metformin Once Daily Versus High-Dose Metformin Twice Daily in Treatment-Naïve Patients with Type 2 Diabetes: a Double-Blind Randomized Trial

INTRODUCTION The aim of this study was to investigate the efficacy and safety of linagliptin + low-dose (LD) metformin once daily versus high-dose (HD) metformin twice daily in treatment-naïve patients with type 2 diabetes. METHODS Patients (n = 689) were randomized (1:1) to double-blind treatment with linagliptin 5 mg + LD metformin (1000 mg) or HD metformin (2000 mg) for 14 weeks. Metformin was initiated at 500 mg/day and up-titrated within 2 weeks; the dose then remained unchanged. The primary endpoint was change in glycated hemoglobin (HbA1c) from baseline to Week 14 in patients who tolerated a daily metformin dose of ≥1000 mg after 2 weeks. RESULTS At Week 14, HbA1c changed from a mean baseline of 8.0% (64 mmol/mol) by -0.99% (-11 mmol/mol) for linagliptin + LD metformin, and -0.98% (-11 mmol/mol) for HD metformin [treatment difference -0.01% (95% confidence interval -0.13, 0.12) (0 mmol/mol), P = 0.8924]. The proportion of patients who achieved HbA1c <7.0% (53 mmol/mol) without occurrence of moderate or severe gastrointestinal (GI) events (including abdominal pain, nausea, vomiting, diarrhea, and decreased appetite) was the same in both groups (51.3% for both). Although the occurrence of moderate or severe GI events was similar, the linagliptin + LD metformin group had fewer mild GI events (18.5% versus 24.3%). The incidence of hypoglycemia was low in both groups. CONCLUSION Linagliptin + LD metformin combination showed similar efficacy and safety to HD metformin. This combination may be an alternative treatment option in patients who may have difficulty tolerating metformin doses >1000 mg/day. FUNDING Boehringer Ingelheim.