Study to Assess the Safety and Biological Activity of AMX0035 for the Treatment of Alzheimer's Disease

Phase II Study to Assess the Safety, Tolerability, and Target Engagement of AMX0035, a Fixed Combination of Sodium Phenylbutyrate and Tauroursodeoxycholic Acid for the Treatment of Alzheimer's Disease

The study is a 24-week, randomized, double-blind, multi-site, placebo-controlled study in participants with mild cognitive impairment (MCI) or early dementia due to Alzheimer's disease (AD).

The study is a 24-week, randomized, double-blind, multi-site, placebo-controlled study in participants with mild cognitive impairment (MCI) or early dementia due to Alzheimer's disease (AD). The study is designed to evaluate the safety, tolerability, drug target engagement and neurobiological effects of treatment with AMX0035 over 24 weeks. The study is designed to yield deep phenotyping insight for the purposes of demonstrating the effects of AMX0035 on mechanistic targets of engagement and disease biology. The study will evaluate diverse disease-relevant markers and produce an informative dataset that will allow for evaluation and correlation of imaging-based markers, neurobiological changes, functional measures, and cognitive outcomes. Participants receive orally administered study drug twice daily for a treatment duration of approximately 24 weeks and attend clinic visits at Screening, Baseline, Week 6, Week 12, Week 18, and Week 24.

Inclusion Criteria:

1. Ages 55-89, inclusive, male or female
2. Diagnosis of "Probable Alzheimer's Disease" or Mild Cognitive Impairment (amnestic or amnestic plus other) with biomarkers that suggest intermediate or high likelihood that the syndrome is due to AD, according to 2011 NIA-AA Workgroup criteria
3. MoCA score >/=8
4. Able to read and write in English sufficiently to complete all study procedures
5. Geriatric Depression Scale <7
6. Willing and able to complete all assessments and study procedures
7. Not pregnant, lactating or of child-bearing potential (women must be >2 years post-menopausal or surgically sterile)
8. Study partner with at least two days per week with contact with patient willing to accompany patient to visits and complete partner study forms
9. No known hypersensitivity to TURSO or Phenylbutyrate
10. If on cholinesterase inhibitor and/or memantine, treatment must have started for no less than 3 months (84 days) prior to baseline and the dosing regimen must have remained stable for 6 weeks (42 days) prior to baseline. The Investigator anticipated that the dosing regimen at baseline would remain unchanged throughout participation in the study.

Exclusion Criteria:

1. Any CNS disease other than suspected AD, such as clinical stroke, brain tumor, normal pressure hydrocephalus, multiple sclerosis, significant head trauma with persistent neurological cognitive deficits or complaints, Parkinson's disease, frontotemporal dementia, or other neurodegenerative diseases

2. Abnormal liver function defined as AST and/or ALT > 3 times the upper limit of normal

3. Renal insufficiency as defined by a serum creatinine > 1.5 times the upper limit of normal

4. Recent (less than 1 year) cholecystectomy or the presence of post-cholecystectomy syndrome or biliary obstruction

5. Clinically significant unstable medical condition (other than AD) that in the Site Investigator opinion would pose a risk to the participant if they were to participate in the study

6. Any contraindication to undergo MRI studies such as:

   1. History of a cardiac pacemaker or pacemaker wires
   2. Metallic particles in the body
   3. Vascular clips in the head
   4. Prosthetic heart valves
   5. Severe claustrophobia impeding ability to participate in an imaging study, or

   MRI findings that show one or more of the following:

   1. More than 4 incidental microhemorrhages
   2. Incidental lacunar infarct with attributable signs or symptoms and with history of stroke
   3. Incidental meningiomas with attributable signs or symptoms
   4. Newly recognized meningioma

7. Major active or chronic psychiatric illness (e.g. depression, bipolar disorder, obsessive compulsive disorder, schizophrenia) that is not stable or well controlled within the previous year prior to baseline

8. Any significant neurodevelopmental disability

9. Current suicidal ideation or history of suicide attempt within 5 years of baseline or significant change from the screening and baseline C-SSRS at the discretion of the Site Investigator

10. History of alcohol or other substance abuse or dependence within the past 2 years

11. Any significant systemic illness or medical condition that could affect safety or compliance with study at the discretion of the Site Investigator

12. Laboratory abnormalities in B12, TSH, or other common laboratory parameters that might contribute to cognitive dysfunction

13. Current use of medications with psychoactive properties that may deleteriously affect cognition (e.g., anticholinergics, centrally-acting antihistamines, antipsychotics, sedative hypnotics, anxiolytics)

14. Use of any investigational therapy being used or evaluated for the treatment of AD is prohibited beginning 3 months (90 days) prior to the Baseline Visit and throughout the study.

15. Use of other investigational agents 1 month (28 days) prior to the Baseline Visit and for the duration of the trial.