LHP588 for Mild to Moderate Alzheimer's Disease

Inclusion Criteria: * AD according to the National Institute on Aging-Alzheimer's Association criteria. * MMSE scores corresponding to mild and moderate AD. * Saliva rinse sample positive for P. gingivalis. * Plasma pTau217 above cutoff. * Subject and caregiver have provided full written informed consent. * Background symptomatic therapy with acetylcholinesterase inhibitors, and/or memantine, are allowed if the dose has been stable for 90 days and no changes are planned during the study. * Modified Hachinski score ≤4 at screening. Exclusion Criteria: * History of cancer requiring systemic therapy in last 5 years. * Evidence of a clinically significant, unstable cardiovascular, pulmonary, renal, hepatic, gastrointestinal, neurologic, or metabolic disease within 6 months prior to screening. * Unstable angina, uncompensated and/or symptomatic congestive heart failure (Grade 2 or higher on the New York Heart Association scale) or myocardial infarction within 6 months. * Acute or poorly controlled blood pressure \>180 mmHg systolic or \>100 mmHg diastolic at screening visit. * History or current evidence of major neurological or psychiatric illness such as schizophrenia, bipolar disorder, Parkinson's Disease, other. * Currently being treated with anti-amyloid beta antibodies or other disease-modifying treatments for dementia. * Other criteria in the Investigator's judgement that may interfere with the ability to participate in the study.