NCT06847321 · Lighthouse Pharmaceuticals, Inc.
Study of LHP588 in Subjects With P. Gingivalis-Positive Alzheimer's Disease
What this study is about
This study is to test LHP588 in persons who have mild to moderate Alzheimer's disease (AD) who have shown progressive mental decline in the last year and who have P. gingivalis (Pg) infection. P. gingivalis infection has been linked to the development of dementia. LHP588 is designed to target the P.
View original scientific description
This study is to test LHP588 in persons who have mild to moderate Alzheimer's disease (AD) who have shown progressive mental decline in the last year and who have P. gingivalis (Pg) infection. P. gingivalis infection has been linked to the development of dementia. LHP588 is designed to target the P. gingivalis bacterium, to potentially help to halt or slow down the progression of AD and its symptoms. A saliva test will be done to determine P. gingivalis infection. Tests for AD include standard questionnaires such as MMSE and a blood test for pTau217. Treatment will be blinded, meaning the participant and the doctor will not know if the participant is receiving LHP588 or placebo. The total time for participation in the study may be up to 64 weeks. This includes a screening period (to ensure the participant is suitable for the study and the study is suitable for the participant) of up to 12 weeks, a treatment period of up to 48 weeks, and a safety follow-up period of 4 weeks after the last dose of the study drug to check the participant's overall health. Treatment is a once-a-day capsule. Caregiver participation is required. The study requires the participant to visit the study center (with the caregiver) at least 20 times within 64 weeks (this does not include any unplanned visits that may be recommended by the study doctor). In addition, the study doctor or clinic staff will contact the participant via phone at least 1 time.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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.
Where
- Phoenix, Arizona
- Scottsdale, Arizona
- Oakland, California
- Orange, California
- Riverside, California
- Sherman Oaks, California
- Englewood, Colorado
- Atlantis, Florida
- Delray Beach, Florida
- Fort Myers, Florida
- Orlando, Florida
- Pensacola, Florida
And 25 more locations — see the full list below.
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 24, 2026 · Source of record for eligibility and locations