A Study of the Effects of CY6463 in Participants With Alzheimer's Disease With Vascular Pathology

Inclusion Criteria:

1. Provide written informed consent prior to the performance of any protocol-specifiedprocedure or, if unable to provide informed consent due to cognitive status,provides assent to participate, with a legally authorized representative (LAR)providing written informed consent on behalf of the participant.

2. 60 years of age or older

3. Meets core clinical criteria for probable AD dementia according to the 2011 NationalInstitute on Aging-Alzheimer's Associated guidelines. Can be based on medicalhistory.

4. Mini-Mental State Examination (MMSE) score of 20 to 26 (inclusive)

5. Confirmation of AD pathophysiology

6. At least 2 cardiovascular risk factors per protocol criteria

7. Magnetic resonance imaging (MRI) scan (existing MRI obtained ≤6 months beforeScreening is acceptable) findings of mild-to-moderate subcortical small-vesseldisease

8. If receiving concomitant or chronic medication(s), has had no change for ≥4 weeksbefore study drug initiation and has no plans to alter the regimen(s) during thestudy

9. If male, agrees to refrain from donating sperm from the Screening visit through 90days after taking the final study drug dose

10. If male, agrees to use protocol-specified, effective contraception methods from thesigning of the informed consent form (ICF) until ≥90 days after taking the finalstudy drug dose.

11. If female, is postmenopausal/not of reproductive potential defined per protocol

12. Agrees to the study procedures, including undergoing lumbar puncture forcerebrospinal fluid (CSF) samples

Exclusion Criteria:

1. Severe visual, auditory, social, or cognitive impairment

2. Dementia-related disorder other than AD or vascular dementia (eg, Parkinson'sdisease, Huntington's disease, frontotemporal dementia, schizophrenia, Lewy bodydementia)

3. Symptomatic large-vessel disease, symptomatic carotid artery disease, large vesselinfarcts, or strategic lacunar infarcts or infarcts>15 mm

4. History of significant central nervous system (CNS) trauma that has affected brainfunction

5. Low blood pressure (BP), defined as systolic BP ≤90 mmHg or diastolic BP ≤60 mmHg.

6. Orthostatic hypotension.

7. Unable to undergo MRI

8. Unable to undergo lumbar puncture procedure

9. Unable to participate in electroencephalography (EEG) protocol due to hearingimpairment or inability to tolerate EEG cap or headphones

10. Uncontrolled or unstable chronic disease

11. Kidney impairment requiring dialysis; history of renal transplant

12. Needs continuous direct medical care and nursing supervision.

13. Family history of short QT syndrome or long QT syndrome

14. Clinically significant cardiac involvement

15. History of cancer. Exceptions: localized cutaneous basal or squamous cell carcinomain the last 5 years, low-grade localized prostate/cervical cancers, or previouslocalized prostate/cervical cancers that have a low likelihood of recurrence

16. Is not suited for study participation in the clinical judgment of the investigator

Additional inclusion and exclusion criteria apply, per protocol.