Glycaemic durability of an early combination therapy with vildagliptin and metformin versus sequential metformin monotherapy in newly diagnosed type 2 diabetes (VERIFY): a 5-year, multicentre, randomised, double-blind trial

Background Early treatment intensification leading to sustained good glycaemic control is essential to delay diabetic complications. Although initial combination therapy has been suggested to offer more opportunities than a traditional stepwise approach, its validity remains to be determined. Methods Vildagliptin Efficacy in combination with metfoRmIn For earlY treatment of type 2 diabetes (VERIFY) was a randomised, double-blind, parallel-group study of newly diagnosed patients with type 2 diabetes conducted in 254 centres across 34 countries. The study consisted of a 2-week screening visit, a 3-week metformin-alone runin period, and a 5-year treatment period, which was further split into study periods 1, 2, and 3. Patients aged 18-70 years were included if they had type 2 diabetes diagnosed within 2 years prior to enrolment, and centrally confirmed glycated haemoglobin A1c (HbA(1c)) of 48-58 mmol/mol (6.5-7.5%) and a body-mass index of 22-40 kg/m(2). Patients were randomly assigned in a 1: 1 ratio either to the early combination treatment group or to the initial metformin monotherapy group, with the help of an interactive response technology system and simple randomisation without stratification. Patients, investigators, clinical staff performing the assessments, and data analysts were masked to treatment allocation. In study period 1, patients received either the early combination treatment with metformin (stable daily dose of 1000 mg, 1500 mg, or 2000 mg) and vildagliptin 50 mg twice daily, or standard-of-care initial metformin monotherapy (stable daily dose of 1000 mg, 1500 mg, or 2000 mg) and placebo twice daily. If the initial treatment did not maintain HbA(1c) below 53 mmol/mol (7.0%), confirmed at two consecutive scheduled visits which were 13 weeks apart, patients in the metformin monotherapy group received vildagliptin 50 mg twice daily in place of the placebo and entered study period 2, during which all patients received the combination therapy. The primary efficacy endpoint was the time from randomisation to initial treatment failure, defined as HbA(1c) measurement of at least 53 mmol/mol (7.0%) at two consecutive scheduled visits, 13 weeks apart from randomisation through period 1. The full analysis set included patients who received at least one randomised study medication and had at least one post-randomisation efficacy parameter assessed. The safety analysis set included all patients who received at least one dose of randomised study medication. This study is registered with ClinicalTrials.gov, NCT01528254. Findings Trial enrolment began on March 30, 2012, and was completed on April 10, 2014. Of the 4524 participants screened, 2001 eligible participants were randomly assigned to either the early combination treatment group (n=998) or the initial metformin monotherapy group (n=1003). A total of 1598 (79.9%) patients completed the 5-year study: 811 (81.3%) in the early combination therapy group and 787 (78.5%) in the monotherapy group. The incidence of initial treatment failure during period 1 was 429 (43.6%) patients in the combination treatment group and 614 (62.1%) patients in the monotherapy group. The median observed time to treatment failure in the monotherapy group was 36.1 (IQR 15.3-not reached [NR]) months, while the median time to treatment failure time for those receiving early combination therapy could only be estimated to be beyond the study duration at 61.9 (29.9-NR) months. A significant reduction in the relative risk for time to initial treatment failure was observed in the early combination treatment group compared with the monotherapy group over the 5-year study duration (hazard ratio 0.51 [95% CI 0.45-0.58]; p<0.0001). Both treatment approaches were safe and well tolerated, with no unexpected or new safety findings, and no deaths related to study treatment. Interpretation Early intervention with a combination therapy of vildagliptin plus metformin provides greater and durable long-term benefits compared with the current standard-of-care initial metformin monotherapy for patients with newly diagnosed type 2 diabetes.