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-specified procedure 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 National Institute on Aging-Alzheimer's Associated guidelines. Can be based on medical history. 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 before Screening is acceptable) findings of mild-to-moderate subcortical small-vessel disease 8. If receiving concomitant or chronic medication(s), has had no change for ≥4 weeks before study drug initiation and has no plans to alter the regimen(s) during the study 9. If male, agrees to refrain from donating sperm from the Screening visit through 90 days after taking the final study drug dose 10. If male, agrees to use protocol-specified, effective contraception methods from the signing of the informed consent form (ICF) until ≥90 days after taking the final study drug dose. 11. If female, is postmenopausal/not of reproductive potential defined per protocol 12. Agrees to the study procedures, including undergoing lumbar puncture for cerebrospinal 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's disease, Huntington's disease, frontotemporal dementia, schizophrenia, Lewy body dementia) 3. Symptomatic large-vessel disease, symptomatic carotid artery disease, large vessel infarcts, or strategic lacunar infarcts or infarcts\>15 mm 4. History of significant central nervous system (CNS) trauma that has affected brain function 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 hearing impairment 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 carcinoma in the last 5 years, low-grade localized prostate/cervical cancers, or previous localized 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.