A Research Study to See How a New Weekly Insulin, Insulin Icodec When Given Along With Semaglutide Helps in Reducing the Blood Sugar Level in Patients With Type 2 Diabetes

Protocol Title: A Single Arm Study Investigating the Glycaemic Control and Safety of Adding Semaglutide to Insulin Icodec in Participants With Type 2 Diabetes Qualifying for Treatment Intensification Short Title: A Research Study to See How a New Weekly Insulin, Insulin Icodec When Given Along With Semaglutide Helps in Reducing the Blood Sugar Level in Patients With Type 2 Diabetes

This study looks at how a new medicine insulin icodec helps in reducing blood sugar levels when given along with semaglutide in patients with type 2 diabetes. Participants will get the medicine insulin icodec once a week in the first part of the study (run-in period-26 weeks). Participants will only enter the second part of the study if the blood sugar levels have not reduced to normal. If blood sugar levels are normal after the first 26 weeks, participants will continue in a 5-week follow up period. In the second part of the study (intensification period-26 weeks), participants will get both insulin icodec and semaglutide once weekly after which they will continue in a 5-week follow up period. Participants will have to inject the study medicines once a week on the same day of the week in a skin fold in the thigh, upper arm or stomach. The study will last for about 13 months. Participants will get a blood glucose meter to check blood sugar levels. In addition, participants will be asked to enter blood sugar levels in the study phone. In addition, Participants will be asked to enter selected few blood sugar values (three times during the study) in a paper diary that will be provided to participants. Women cannot take part if pregnant, breast-feeding or plan to get pregnant during the study period.

Inclusion Criteria:

• Diagnosed with type 2 diabetes (T2D) greater than or equal to (>=) 180 days prior to the day of screening
• HbA1c from 7.5%-10.5% (58-91 millimoles per mole [mmol/mol]) (both inclusive)
• Treated with once daily or twice daily basal insulin (minimum of 0.25 international units per kilograms per day (IU/kg/day) or 20 IU/day) without concomitant glucagon-like peptide-1 receptor agonists (GLP-1 RA) >= 90 days prior to the day of screening with or without any of the following antidiabetic drugs/regimens with stable doses >= 90 days prior to screening: metformin, sulfonylureas, meglitinides (glinides), dipeptidyl peptidase-4 (DPP-4) inhibitors, Sodium-glucose Cotransporter-2 (SGLT2) inhibitors, thiazolidinediones, alpha-glucosidase inhibitors. Oral combination products (for the allowed individual oral anti-diabetic drugs)

Exclusion Criteria:

• Presence or history of pancreatitis (acute or chronic) within 180 days before screening
• Myocardial infarction, stroke, hospitalisation for unstable angina pectoris or transient ischaemic attack within 180 days prior to the day of screening and between screening and initiation
• Chronic heart failure classified as being in New York Heart Association (NYHA) Class IV at screening
• Planned coronary, carotid or peripheral artery revascularization
• Uncontrolled and potentially unstable diabetic retinopathy or maculopathy. Verified by a fundus examination performed within the past 90 days prior to screening or in the period between screening and initiation. Pharmacological pupil-dilation is a requirement unless using a digital fundus photography camera specified for non-dilated examination