Efficacy and Safety of AD-35 in Treatment of Subjects With Mild to Moderate Alzheimer's Disease

Approximately 88 subjects are planned to be enrolled for the entire study. Initially,
approximately 30 subjects will be randomized via a centralized interactive response
technology (IRT) in a 1:2 ratio (ie, approximately 10 and 20 subjects) to receive placebo and
60 mg AD-35. The Data Safety Monitoring Board (DSMB) will review safety information after the
first 30 subjects have completed the Day 30 Visit to confirm appropriateness of
protocol-defined dosage modification.

If the average post-dose heart rate corrected QT interval using Fridericia's formula (QTcF)
change from baseline is <15 msec for Day 15 and Day 30, and no more than 2 subjects have a
QTcF change from baseline >30 msec, then, based on DSMB review, future subjects will be
enrolled and will be randomized in a 1:1:3 ratio to receive placebo, 60 mg AD-35, and 90 mg
AD-35, respectively.After the first 6 months of double-blind treatment, subjects on active
study drug will remain on the current dose, and subjects assigned to placebo will receive 60
mg and 90 mg AD-35 in a 1:2 ratio, respectively, for an additional 6 months of open-label
treatment.

Inclusion Criteria:

1. Subjects must be diagnosed with probable AD in accordance with the National Institute
on Aging and Alzheimer's Association (NIA-AA) (2011) criteria.

2. Subjects must have a Mini-Mental State Examination (MMSE) score of ≥15 and ≤26 at
screening and baseline.

3. Subjects must have a brain magnetic resonance imaging (MRI) scan that is consistent
with a clinical diagnosis of probable AD.

4. Subjects should not have received Aβ-based or tau-based treatment for AD.

5. Subjects who were previously treated with Acetyl cholinesterase inhibitor (AChEI) or
memantine, must have been off of the therapy for at least 3 months prior to baseline
assessments. Subjects who have been taking AChEI or memantine for ≤7 days may be
considered for enrollment in this study.

6. For subjects who are currently receiving other non-excluded prescription or
over-the-counter medications that might affect cognitive function (eg,
non-anticholinergic antidepressants, atypical antipsychotics, non-benzodiazepine
anxiolytics, soporifics, centrally acting anticholinergic antihistamines, centrally
acting anticholinergic antispasmodics):

- Treatment must be at a stable dose for ≥1 month prior to randomization and
throughout the duration of the study.

- Treatment given intermittently and on a short-term basis must not be administered
within 5 half-lives prior to the screening of neurocognitive assessments.

7. Subjects must be male or female between 50 years to 85 years of age (inclusive), at
screening.

8. Female subjects must be post-menopausal for at least 2 consecutive years or surgically
sterile (bilateral tubal ligation, hysterectomy, or bilateral oophorectomy) for at
least 6 months prior to screening.

9. Male subjects with partners of reproductive potential must agree to use a reliable
means of contraception (eg, minimum condom + spermicide) during the study and 30 days
after discontinuing the study drug.

10. Subjects must have a reliable caregiver with contact at least 3 times per week
(combination of face to face visits and telephone contact acceptable). The caregiver
must be able to oversee the subject's compliance with study drug and participate in
the subject's clinical assessment, to provide meaningful input into the NPI, ADCS-ADL,
and CIBIC+.

11. Subjects (or subject's legally authorized representatives and their caregivers) must
be able to provide informed consent.

12. Subjects (and their caregivers) must be able to read, write, speak, and understand
English to ensure compliance with cognitive testing and study visit procedures.

13. Subjects (and their caregivers) must be willing and able to comply with the protocol's
requirements.

14. Subjects must weigh between 45 kg and 90 kg (inclusive), at screening.

15. Subjects must be in general good health in the opinion of the Investigator, based on
medical history, physical examination, vital signs, 12-lead electrocardiogram (ECG) in
triplicate, and clinical laboratory values.

Exclusion Criteria:

1. Lack of peripheral venous access.

2. Uncorrected impairment of vision or hearing that would preclude the subject from
taking tests, or subjects lacking the ability to communicate.

3. Inability to tolerate MRI procedures or contraindication to MRI, including but not
limited to MRI incompatible pacemakers; implantable cardioverter defibrillators;
cochlear implants; cerebral aneurysm clips; implanted infusion pumps; implanted nerve
stimulators; metallic splinters in the eye; other magnetic, electronic, or mechanical
implants; or any other clinical history or examination finding that, in the judgment
of the Investigator, would pose a potential hazard in combination with MRI.

4. Severe or unstable medical condition that, in the opinion of the Investigator or
Sponsor, would interfere with the subject's ability to complete the study assessments.

5. History or presence of clinically evident vascular disease potentially affecting the
brain (eg, stroke, clinically significant carotid or vertebral stenosis or plaque,
aortic aneurysm, intracranial aneurysm, cerebral hemorrhage, arteriovenous
malformation).

6. History of severe, clinically significant (persistent neurologic deficit or structural
brain damage) central nervous system trauma (eg, cerebral contusion).

7. History or presence of intracranial tumor (eg, meningioma, glioma).

8. Presence of infections that affect the brain function or history of infections that
resulted in neurologic sequelae (eg, syphilis, neuroborreliosis, viral or bacterial
meningitis/encephalitis,human immunodeficiency virus encephalopathy).

9. History or presence of systemic autoimmune disorders potentially causing progressive
neurologic disease (eg, multiple sclerosis, lupus erythematosus, anti-phospholipid
antibody syndrome, Behçet disease).

10. History or presence of psychiatric disease other than AD that may affect cognition or
prevent completion of study procedures, including but not limited to clinically
significant major psychiatric disorder according to the criteria of the Diagnostic and
Statistical Manual of Mental Disorders-V (DSM-V) (eg, major depression, schizophrenia,
bipolar disorder).

• A history of major depression is acceptable if no episode has been reported within
the previous 5 years.

11. History or presence of a neurologic disease other than AD that may affect cognition,
including but not limited to Parkinson's disease, corticobasal degeneration, dementia
with Lewy bodies, Creutzfeldt-Jakob disease, progressive supranuclear palsy,
frontotemporal degeneration, Huntington's disease, normal pressure hydrocephalus, and
hypoxia.

12. History of seizures with the exception of childhood febrile seizures.

13. Known or suspected history of alcohol or drug abuse within the previous 5 years (DSM-V
criteria).

14. Evidence of malignancies, acute infections, renal failure that requires dialysis, or
other unstable medical disease not related to AD that in the Investigator's opinion
would preclude subject participation.

• This does not include any cancer (except adequately treated basal or squamous cell
skin cancer) that is not being actively treated with anti-cancer drugs or radiotherapy
as well as cancers that are considered to have low probability of recurrence (with
supporting documentation of this from the treating oncologist, if possible).

15. History or presence of atrial fibrillation that poses a risk for future stroke in the
Investigator's judgment.

16. Severe heart disease (history of myocardial infarction, congestive heart disease,
history of unstable angina pectoris, clinically significant ECG abnormality) within 6
months prior to screening. Subjects with peripheral arterial disease will not be
excluded if they are stable for at least 6 months prior to screening.

17. Clinically significant vital signs, laboratory, or ECG abnormalities (eg, abnormally
prolonged or shortened heart rate, clinical significant arrhythmias, corrected QT
interval [QTcF] >450 ms) in the Investigator's judgement. ECG abnormalities should be
confirmed by Investigator based on the central read results provided by the ECG core
laboratory (Medpace Cardiovascular Core Laboratory [MCCL]).

18. Subjects must not have an estimated glomerular filtration rate of <30 mL/min/1.73 m2,
at screening.

19. Impaired hepatic function, as indicated by transaminases >2 times the upper limit of
normal or abnormalities in synthetic function tests judged by the Investigator to be
clinically significant.

20. Evidence of poorly-controlled diabetes (glycosylated hemoglobin >8.0%).

21. Presence of superficial siderosis of central nervous system, or >4 cerebral
microhemorrhages, or evidence of a prior cerebral macrohemorrhage as assessed by
T2*-weighted gradient-recalled-echo (GRE) MRI.

22. Presence of significant cerebral vascular pathology as assessed by MRI.

23. Treatment with any investigational agent within 5 half-lives or 4 weeks prior to
screening, whichever is longer.

24. Cognitive dysfunction that might be due to past or current medication (eg,
chemotherapy, steroids).

25. Treatment with any biologic therapy within 5 half-lives or 3 months prior to
screening, whichever is longer, or any subject who has been in an Alzheimer Aβ or tau
vaccination trial unless known to have received only placebo.

26. Treatment with anticholinergic antidepressants, typical antipsychotics, or
barbiturates.

27. Chronic use of opiates, opioids, or benzodiazepines:

• Intermittent short-term use is allowed except within 5 half-lives prior to any
neurocognitive assessment.

28. Use or intention to use any medications/products that are cytochrome P450 (CYP)3A4
substrates with narrow therapeutic indexes.

29. Use or intention to use any medications/products that are known to be strong
inducers/inhibitors of CYP3A4 within 7 days prior to the first dose and throughout the
period of study drug administration.

30. Consumption of grapefruit juice or grapefruit-containing products within 7 days prior
to the first dose and throughout the period of study drug administration.