This study is looking at the way insulin icodec stays and moves over time in the blood after injections in Chinese people with type 2 diabetes.

Participants will get insulin icodec once a week for 6 weeks. The medicine will be injected under the skin of the thigh. There will also be a run-in period that will last between 1 week and 8 weeks with daily doses of insulin degludec before start on insulin icodec.

The study will last for about 15 to 22 weeks. Participants will have about 17 visits with the study doctor including phone contact during your run-in period.

Participants will have blood samples taken at the clinic visits. Several samples of participants blood will be taken for up to 48 hours after getting the first and the last dose of insulin icodec.

Participants must be a Chinese person diagnosed with type 2 diabetes for at least 6 months and be on basal insulin treatment for at least 2 months before participating in the study.

Women: Women cannot take part if pregnant, breast-feeding or plan to become pregnant during the study period

Inclusion Criteria:

• Chinese male or female
• Aged 18-64 years (both inclusive) at the time of signing informed consent
• Body mass index between 18 and 38 kg/m^2 (both inclusive)
• HbA1c (glycated haemoglobin) below or equal to 9% at screening
• Current daily basal insulin treatment greater than or equal to 0.2 (I)U/kg/day greater than or equal to 60 days prior to the day of screening with or without any of the following anti-diabetic drugs/regimens with stable doses greater than or equal to 60 days prior to the day of screening:
• Any metformin formulation
• Other oral antidiabetic drugs: DPP-4 (Dipeptidyl-peptidase-4) Inhibitors , SGLT2 (Sodium-glucose co-transporter-2) inhibitors, Oral combination products (for the allowed individual oral antidiabetic drugs)
• Oral or injectable GLP-1 (Glucagon Like Peptide 1) Receptor Agonists

Exclusion Criteria:

• Known or suspected hypersensitivity to trial product(s) or related products.
• Female who is pregnant, breast-feeding or intends to become pregnant or is of child-bearing potential and not using an adequate contraceptive method (adequate contraceptive measures as required by local regulation or practice).
• Uncontrolled and potentially unstable diabetic retinopathy or maculopathy. Verified by a fundus examination performed within 90 days prior to screening or in the period between screening and run-in. Pharmacological pupil-dilation is a requirement unless using a digital fundus photography camera specified for non-dilated examination.
• Recurrent severe hypoglycaemia (more than 1 severe hypoglycaemic event within the past 180 days) or hypoglycaemic unawareness as judged by the investigator or hospitalisation for diabetic ketoacidosis within the past 180 days prior to the day of screening

According to the Novo Nordisk disclosure commitment on novonordisk-trials.com