An Evaluation of Treatments for Sustained Clinical Response (18 Months) in Symptomatic Alzheimer's Disease

A multicentre, interventional, multi-arm, multi-stage Phase 3 trial including randomisation, double blinding, placebo control evaluation of treatments for sustained clinical response (18 months) in symptomatic Alzheimer's Disease in a population representative of people with Alzheimer's disease in the UK.

Inclusion Criteria * Patient meets all inclusion criteria: 1\. Adults aged ≥55 years on the day of screening, no upper age limit 2. Either: 1. Confirmed clinical diagnosis of Alzheimer's Disease (AD) 2. Confirmed clinical diagnosis of Mixed Dementia consisting of Alzheimer's Disease and Vascular Dementia 3. Mini Mental State Examination score of ≥17 4. Confirmatory blood biomarker testing (pTau-217) (positive or intermediate via validated assays) ≤ 365 days prior to screening or between screening and randomisation or a positive amyloid PET scan (if available) or a positive amyloid CSF test (if available) 5. Randomisation should ideally take place within 4 weeks of the screening visit but no later than 8 weeks after the screening visit 6. Must be able and willing to comply with the treatment and assessment schedule and requirements including being able to start trial treatment ≤ 2 weeks after randomisation 7. Willing and able to have MRI scans in accordance with the assessment schedule unless participant is clinically contraindicated due to: 1. Pacemakers or defibrillators (unless MRI-conditional models) 2. Aneurysm clips, stents or metal implants (unless MRI safe) 3. Cochlear implants (unless MRI-conditional models) 4. Metal fragments in the body 5. Severe claustrophobia 8. Negative pregnancy test ≤4 weeks prior to randomisation for women of child-bearing potential 9. Normal liver function at screening consisting of all the following: 1. Total serum bilirubin \