A Research Study Looking at the Effect of Semaglutide on the Immune System and Other Biological Processes in People With Alzheimer's Disease

Inclusion Criteria:

• Male or female, aged 55-75 years (both inclusive) at the time of signing theinformed consent

• Mild cognitive impairment (MCI) or mild dementia of the Alzheimer's type accordingto the National Institute on Aging- Alzheimer's Association (NIA-AA) 2018 criteria

• Clinical dementia rating (CDR) global score of 0.5 or 1 at screening (visit 1)

• Amyloid positivity established with either historical amyloid positron emissiontomography (PET) or historical cerebrospinal fluid (CSF) Aβ1-42 or historical CSFAβ1-42/Aβ1-40 (historical data within the last 5 years) or blood sample for amyloidbiomarker (Aβ42/Aβ40 ratio and p-tau217/np-tau217 ratio) at screening (visit 1)

• Treated with acetylcholinesterase inhibitors (approved for the treatment ofAlzheimer's disease) and on stable dose for greater than 90 days before screening (visit 1)

Exclusion Criteria:

• Brain magnetic resonance imaging (MRI) scan suggestive of clinically significantstructural central nervous system (CNS) disease confirmed by local read (examplecerebral large-vessel disease [large vessel (cortical) infarcts greater than 10millimeter (mm) in diameter], prior macro-haemorrhage [greater than 1centimeter cube (cm^3)], cerebral vascular malformations, cortical hemosiderosis, intracranialaneurism(s), intracranial tumours, changes suggestive of normal pressurehydrocephalus)

• Brain MRI scan suggestive of significant small vessel pathology confirmed by localread and defined as greater than 1 lacunar infarct and/or white matterhyperintensity (WMH) Fazekas13 scale greater than 2, (white matter [WM] greater than 20 mm) in the deep white matter and periventricular regions

• History or evidence of autoimmune diseases such as inflammatory bowel disease,rheumatoid arthritis, lupus, glomerulonephritis, psoriasis (but not limited to): Anyother medical condition that would require use of systemic corticosteroids orimmunosuppressants or immunostimulants in the 12 months prior to screening (visit 1)

• Received a vaccine product (including booster) 4 weeks prior to screening (visit 1)or expected to receive a vaccine product (including booster) before visit 5

• Use of any systemic immunomodulating drugs (small molecules and/or biologics) in thelast 12 months prior to screening (visit 1) or anticipated use of such drugs duringstudy intervention period 1 (i.e., during the first 12 weeks of treatment untilvisit 5), such as corticosteroids for systemic use, immunostimulants andimmunosuppressants