Research Study Comparing a New Medicine "Fast-acting Insulin Aspart" to Another Already Available Medicine "NovoRapid"/"NovoLog" in People With Type 2 Diabetes

Inclusion Criteria: - Male or female, age equal to or above 18 years at the time of signing informed consent. - Diagnosed with type 2 diabetes mellitus for 10 years or longer prior to screening (Visit 1). - Treated with a basal-bolus insulin regimen for 1 year or longer prior to the day of screening (Visit 1). A basal-bolus insulin regimen is defined as basal insulin once or twice daily and bolus insulin analogue taken with meals at least 3 times daily. Treatment with premixed insulin or soluble insulin combination is not considered a basal-bolus regimen. - Treated with or without oral antidiabetic drugs including extended release formulations. - HbA1c 7.0-10.0% (both inclusive) as assessed by central laboratory at screening (Visit 1). Exclusion Criteria: - Any of the following: myocardial infarction, stroke, hospitalization for unstable angina or transient ischaemic attack within the past 180 days prior to the day of screening (Visit 1). - Subjects presently classified as being in New York Heart Association (NYHA) Class IV. - Planned coronary, carotid or peripheral artery revascularisation known on the day of screening (Visit 1). - Treatment with injectable GLP-1 receptor agonists in a period of 90 days prior to screening (Visit 1). - Anticipated initiation or change in concomitant medications (for more than 14 consecutive days) known to affect weight or glucose metabolism (e.g. treatment with orlistat, thyroid hormones, or corticosteroids).