This study will look if CagriSema can lower kidney damage in people with chronic kidney disease (CKD), type 2 diabetes (T2D) and overweight or obesity. CagriSema is a new investigational medicine. CagriSema cannot yet be prescribed by doctors. The study will compare CagriSema to the 2 medicines semaglutide and cagrilintide, when they are taken alone. It will also compare CagriSema to a "dummy" medicine (also called placebo) without any active ingredient. Participant will either get CagriSema, semaglutide, cagrilintide or placebo. Which treatment participant will get is decided by chance (like flipping a coin). Study doctor will not know which of the study medicines participant will get. For each participant, the study will last for about 35 weeks.

Inclusion Criteria:

• Male or female.
• Age 18 years or above at the time of signing the informed consent.
• Diagnosed with type 2 diabetes mellitus ≥ 180 days before screening.
• Body mass index (BMI) ≥ 27.0 kilograms per meter square (kg/m^2) at screening. BMI will be calculated in the eCRF (electronic case report form) based on height and body weight at screening.
• HbA1c less than or equal to (≤) 10.5% (91 millimoles per mole [mmol/mol]) as assessed by central laboratory at screening.
• Kidney impairment defined by serum creatinine and cystatin C-based eGFR ≥ 15 and < 90 milliliters per minutes per 1.73^m^2 (mL/min/1.73 m^2) (CKD-EPI 2021) as assessed by central laboratory at screening.
• Albuminuria defined by UACR ≥ 100 and < 5000 milligram per gram (mg/g) as assessed by central laboratory at screening.
• Treatment with maximum labelled or tolerated dose of an angiotensin converting enzyme (ACE) inhibitor or an angiotensin II receptor blocker (ARB), unless such treatment is contraindicated or not tolerated, in the opinion of the investigator. Treatment dose must be stable for at least 30 days prior to screening.

Exclusion Criteria:

• Female who is pregnant, breast-feeding or intends to become pregnant or is of childbearing potential and not using a highly effective contraceptive method.
• Congenital or hereditary kidney diseases including polycystic kidney disease, autoimmune kidney diseases including glomerulonephritis or congenital urinary tract malformations.
• Use of any glucagon-like peptide-1 receptor agonist (GLP-1RA) (including medication with GLP-1RA activity, e.g., GIP/GLP-1RA) or amylin analogue within 60 days prior to screening.
• Myocardial infarction, stroke, transient ischaemic attack, or hospitalization for unstable angina pectoris within 60 days before screening.
• Chronic or intermittent haemodialysis or peritoneal dialysis within 90 days before screening.
• Uncontrolled and potentially unstable diabetic retinopathy or maculopathy. Verified by an eye examination performed within 90 days before screening or in the period between screening and randomisation. Pharmacological pupil-dilation is a requirement unless using a digital fundus photography camera specified for non-dilated examination.
• Presence or history of malignant neoplasms or in situ carcinomas (other than basal or squamous cell skin cancer, low-risk prostate cancer, or in-situ carcinomas of the cervix or carcinoma in situ/high grade prostatic intraepithelial neoplasia (PIN) within 5 years before screening.

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