Comparison of NN5401 Versus Insulin Glargine, Both Combined With Metformin Treatment, in Subjects With Type 2 Diabetes

Inclusion Criteria:

• For MAIN period (NN5401-3590):

• Diagnosis of type 2 diabetes mellitus for at least 6 months

• Insulin naïve subjects

• Treatment with metformin and at least one other oral antidiabetic drug for at least 3months before trial start

• Glycosylated haemoglobin (HbA1c) between 7.5 - 11.0% (both inclusive)

• Body Mass Index (BMI) no higher than 40.0 kg/m^2

• For EXTENSION period (NN5401-3726):

• Informed consent obtained before any trial-related activities

• Must have completed the 26-week treatment period (visit 28) in trial NN5401-3590

Exclusion Criteria:

• For MAIN period (NN5401-3590):

• Treatment with glucagon like peptide-1 (GLP-1) receptor agonists and/orthiazolidinedione(s) within the last 3 months prior to trial start

• Cardiovascular disease diagnosed within 6 months before trial start

• For EXTENSION period (NN5401-3726):

• Anticipated change in concomitant medication known to interfere significantly withglucose metabolism, such as systemic corticosteroids, beta-blockers, Monoamine oxidase (MAO) inhibitors

• Anticipated significant lifestyle changes during the trial, e.g. shift work (includingpermanent night/evening shift workers), as well as highly variable eating habits asjudged by the physician)

• Pregnancy, breast-feeding, the intention of becoming pregnant or not using adequatecontraceptive measures according to local requirements