Efficacy and Safety of Semaglutide Once-weekly Versus Sitagliptin Once-daily as add-on to Metformin and/or TZD in Subjects With Type 2 Diabetes

Inclusion Criteria: - Japan: Age minimum 20 years - Subjects diagnosed with type 2 diabetes and on stable treatment in a period of 90 days prior to screening with either metformin above or equal to 1500 mg (or maximum tolerated dose), pioglitazone above or equal to 30 mg (or maximum tolerated dose), rosiglitazone above or equal to 4 mg (or maximum tolerated dose) or a combination of either metformin/pioglitazone or metformin/rosiglitazone (doses as for individual therapies). Stable is defined as unchanged medication and unchanged dose - HbA1c 7.0 - 10.5 % (53 - 91 mmol/mol) (both inclusive) Exclusion Criteria: - Females of childbearing potential who are pregnant, breast-feeding or intend to become pregnant or are not using an adequate contraceptive method throughout the trial including the 5 weeks follow-up period (adequate contraceptive measures as required by local law or practice) - Any chronic disorder or severe disease which, in the opinion of the investigator, might jeopardise subject's safety or compliance with the protocol - Treatment with glucose lowering agent(s) other than stated in the inclusion criteria in a period of 90 days before screening. An exception is short-term treatment (below or equal to 7 days in total) with insulin in connection with inter-current illness - History of chronic or idiopathic acute pancreatitis - Screening calcitonin value above or equal to 50 ng/L (pg/mL) - Personal or family history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia syndrome type 2 (MEN 2) - Impaired renal function defined as estimated glomerular filtration rate (eGFR) below 60 ml/min/1.73 m2 per modification of diet in renal disease (MDRD) formula (4 variable version) - Acute coronary or cerebrovascular event within 90 days before randomisation - Heart failure, New York Heart Association (NYHA) class IV