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 3
months 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/or
thiazolidinedione(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 with
glucose metabolism, such as systemic corticosteroids, beta-blockers, Monoamine
oxidase (MAO) inhibitors

- Anticipated significant lifestyle changes during the trial, e.g. shift work
(including permanent night/evening shift workers), as well as highly variable eating
habits as judged by the physician)

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