Research Study Comparing a New Medicine Semaglutide to Liraglutide in People With Type 2 Diabetes

Inclusion Criteria: - Male or female, age 18 years or older at the time of signing informed consent - Diagnosed with type 2 diabetes mellitus - HbA1c of 7.0-11.0 % (53 - 97 mmol/mol) (both inclusive) - Stable daily dose(s) including any of the following anti-diabetic drug(s) or combination regimens 90 days prior to the day of screening: a) Biguanides (metformin above or equal to 1500 mg or maximum tolerated dose documented in the subject's medical record). b) Sulphonylureas (above or equal to half of the maximum approved dose according to local label or maximum tolerated dose as documented in subject medical record). c) SGLT-2 inhibitors (above or equal to half of the maximum approved dose according to local label or maximum tolerated dose as documented in subject medical record) Exclusion Criteria: - Family or personal history of multiple endocrine neoplasia type 2 or medullary thyroid carcinoma. Family is defined as a first degree relative - History or presence of pancreatitis (acute or chronic) - History of diabetic ketoacidosis - 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 - 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 - Renal impairment measured as estimated Glomerular Filtration Rate (eGFR) value of below 30 ml/min/1.73 sqm as defined by KDIGO 2012 classification - Impaired liver function, defined as ALT above or equal to 2.5 times upper normal limit at screening - Proliferative retinopathy or maculopathy requiring acute treatment. Verified by fundus photography or dilated fundoscopy performed within the past 90 days prior to randomisation