Inclusion Criteria:
MCI due to AD:
1. Male or female, aged 55-85 years (both inclusive) at the time of signing informed consent.
2. Participant must have a subjective memory concern as reported by participant, study partner, or clinician.
3. Mini-Mental State Exam31 score between 24 and 30, inclusive
4. Clinical Dementia Rating (CDR)32 Global = 0.5. Memory Box score must be at least 0.5
Mild AD:
1. Male or female, aged 55-85 years (both inclusive) at the time of signing informed consent.
2. MCI or Mild dementia of the Alzheimer's type according to the NIA-AA 2018 criteria.
3. CDR global score of 0.5 and CDR domain score of 0.5 or more in at least one of the three instrumental activities of daily living categories (personal care, home \& hobbies, community affairs) Or CDR global score of 1.0
4. MMSE ≥20
Additional Inclusion Criteria for Both Diagnoses:
1. Age 55-85 (inclusive)
2. Abnormal memory function documented by scoring within the education adjusted ranges on the Logical Memory II subscale (Delayed Paragraph Recall) from the Wechsler
Memory Scale - Revised:
* Less than or equal to 11 for 16 or more years of education
* Less than or equal to 9 for 8 - 15 years of education
* Less than or equal to 6 for 0 - 7 years of education
3. Amyloid positivity established using the C2N Precivity2 Plasma test (Aβ42/40 plus p tau217/np-tau217. (This test uses a statistical algorithm to integrate a patient's Aβ42/40 Ratio and p-Tau217 Ratio to calculate the Amyloid Probability Score 2 (APS2) and determines whether a patient is positive or negative for brain amyloid deposition based on a binary cutoff value).
4. Stable permitted medications for 4 weeks or longer as specified in Section 4.6.3, including:
a. Memantine and cholinesterase inhibitors are allowable if stable for 12 weeks prior to screen.
5. Geriatric Depression Scale33 score of less than or equal to 14.
6. Study Partner is available who has frequent contact with the participant (e.g., an average of 10 hours per week or more) and can accompany the participant to most visits to answer questions about the participant.
7. Adequate visual and auditory acuity to allow neuropsychological testing.
8. Good general health with no additional diseases/disorders expected to interfere with the study.
9. For women: participant is not pregnant, lactating, or of childbearing potential (i.e., women must be two years post-menopausal or surgically sterile).
10. For men: male participants with female partners of childbearing potential must use an effective method of contraception from dosing on Day 1 until 1 month after the lastadministration of study medication and agreed not to donate sperm until 1 month after the last administration of study medication.
11. Completed six grades of education or has a good work history.
12. Must speak English fluently.
13. Provide written informed consent. Participants must have the capacity to consent.
Exclusion Criteria:
Any other significant neurologic disease including Parkinson's disease, multi-infarct dementia, Huntington's disease, normal pressure hydrocephalus, brain tumor, progressive supranuclear palsy, seizure disorder, subdural hematoma, multiple sclerosis, or history of significant head trauma followed by persistent neurologic deficits or known structural brain abnormalities. 2. Major depression, bipolar disorder as described in DSM-V within the past 1 year or psychotic features, agitation, or behavioral problems within 3 months, which could lead to difficulty complying with the protocol. 3. History of schizophrenia (DSM V criteria). 4. History of alcohol or substance abuse or dependence within the past 2 years (DSM V criteria). 5. Clinically significant or unstable medical condition, including uncontrolled hypertension, uncontrolled diabetes, or significant cardiac, pulmonary, renal (defined by eGFR score \<60 mL/min/1.73 m²), hepatic impairment, endocrine, or other systemic disease that, in the opinion of the Investigator, may put the participant at risk because of participation in the study, influence the results, or affect the participant's ability to participate in the study.
Participants with moderate or severe hepatic impairment, defined as Child-Pugh Class B or C, are excluded. 6. Has had a history within the last 5 years of a primary or recurrent malignant disease with the exception of non-melanoma skin cancers, resected cutaneous squamous cell carcinoma in situ, basal cell carcinoma, cervical carcinoma in situ, or in situ prostate cancer with normal prostate-specific antigen post-treatment. 7. Clinically significant abnormalities in B12 or TFTs that might interfere with the study.
8\. Clinically significant abnormalities in screening laboratories or ECG. 9. Residence in a skilled nursing facility. 10. Use of any excluded medication as described in Section 4.6.2, including:
* Use centrally acting anti-cholinergic drugs.
* Use of any investigational drugs within 4 weeks or 5 half-lives, whichever is longer, prior to screening. 11. A current blood clotting or bleeding disorder, or significantly abnormal PT or PTT at screening. 12. Contraindications for MRI studies, including claustrophobia, the presence of metal (ferromagnetic) implants, or cardiac pacemaker. 13. Participants whom the Site PI deems to be otherwise ineligible. 14. Current use of monoamine oxidase inhibitors (MAOIs) or use within 14 days (or 5 half-lives, whichever is longer) prior to screening, This includes non-selective MAOIs (phenelzine, tranylcypromine, isocarboxazid), MAO-B inhibitors (selegiline, rasagiline, safinamide), reversible MAO-A inhibitors (moclobemide), and other agents with MAOI A inhibitory activity (linezolid, methylene blue at doses \>1 mg/kg). This exclusion is required because 2-HOBA has demonstrated MAO-A inhibitory activity in vitro.
