Study Evaluating Safety, Tolerability, and PK of Multiple Ascending Doses of GC021109 in Subjects With Mild to Moderate Alzheimer's Disease

Inclusion Criteria:

1. Male or female subjects aged 55-85 years, inclusive, at the time of informed consent.

2. Subjects diagnosed with mild to moderate AD as determined by the following:

1. Diagnosis of probable AD according to the 2011 NIA-AA criteria

2. MMSE (using serial 7's) score of 12-26 at screening (Mild defined as 20-26 and
Moderate defined as 12-19)

3. Documentation in the clinic notes of mild/moderate AD

3. If on AD therapy, stable dose for at least 3 months prior to screening.

4. All male subjects must practice effective contraception during the study. Females of
childbearing potential must use a medically accepted form of birth control, unless
postmenopausal for > 1 year (as documented by elevated follicle-stimulating hormone
[FSH]) or surgically sterile. All females of childbearing potential must have a
negative serum pregnancy test (human chorionic gonadotropin beta [hCGβ]) at screening
and a negative urine pregnancy test on Day 1 pre-dose.

5. Body mass index (BMI) between 18 and 35 kg/m2, inclusive, at screening.

6. Must have an eligible caregiver (who spends a minimum of 10 hours per week with the
subject) who will be available for the duration of the study to serve as the
subject's designee. Caregiver must be willing to comply with study procedures.

7. Caregiver must sign a caregiver ICF after the nature and risks of study participation
have been fully explained to them.

8. Patients who are capable, according to the Investigator, or patient's legally
authorized representative, must sign a patient ICF after the nature and risks of
study participation have been fully explained to them.

9. Patients who are capable of providing assent but not capable of signing the ICF,
according to the Investigator, should provide assent for study participation.

1. Patients who sign the ICF are not required to provide a separate assent.

2. Patients who are not capable of providing assent are still allowed to
participate provided the patient's legally authorized representative agrees to
participation.

Investigators must document the reasons for any patient that is unable to provide
assent and maintain this documentation with the consent/assent documents.

10. Must be able to comply with all study requirements and restrictions for the duration
of the study.

11. Non-smoker and non-tobacco user for a minimum of 3 months prior to screening and for
the duration of the study.

12. Ability to swallow capsules.

Exclusion Criteria:

1. MRI findings inconsistent with AD within the previous 12 months. All subjects must
have had a MRI within the previous 12 months to be eligible.

2. History or current evidence of any clinically significant cardiac, endocrinologic,
hematologic, hepatobiliary, immunologic, metabolic, urologic, pulmonary, neurologic,
dermatologic, psychiatric, renal, or other major disease, as determined by the
Investigator.

3. History of cancer within the past five years (excluding non-melanoma skin cancer).

4. Active suicidal ideation reported on the Columbia - Suicide Severity Rating Scale (C
SSRS) at screening.

5. Clinically significant abnormal laboratory test values at screening (as determined by
the Investigator), including:

1. any values for alanine aminotransferase (ALT) or aspartate aminotransferase
(AST) that are 1.5 times above the upper limit of the reference range

2. any values for total or direct bilirubin that are 1.5 times above the upper
limit of the reference range

3. estimated glomerular filtration rate <85ml/min/1.73m2.

6. Subjects with a QTc of ≥450 msec for males and ≥470 msec for females at screening.

7. Participation in another clinical trial or treatment with an investigational agent
within 30 days or 5 half-lives, whichever is longer, prior to Day 1.

8. Subjects with a body weight > 120 kg at screening.

9. History of alcohol or drug abuse or dependence within 12 months of screening as
determined by the Investigator.

10. Clinically significant infection within 3 months of screening as determined by the
Investigator.

11. Any conditions that, in the opinion of the Investigator, would make the subject
unsuitable for enrollment or could interfere with the subject's participation in or
completion of the study.

12. Positive urine screen for prohibited drugs (cocaine, cannabinoids, nicotine [urine
cotinine is the detection mechanism for nicotine], opiates, barbiturates,
amphetamines, and benzodiazepines) or positive alcohol Breathalyzer on Day 1.

13. Positive blood screen for human immunodeficiency virus (HIV), hepatitis B surface
antigen (HBsAg), or hepatitis C virus antibody (HCVAb) at screening.

14. Known or suspected hypersensitivity or idiosyncratic reaction to study medication or
any components thereof.

15. Has donated blood within 3 months of screening or plans to donate blood within 3
months of study completion.