Efficacy and Safety of 26-Week Treatment of AR1001 in Patients With Mild to Moderate Alzheimer's Disease

Alzheimer's Disease (AD) is the most prevalent neurodegenerative disorder in The United
States affecting approximately 5.4 million Americans. AD is characterized by progressive loss
in memory and as well as a decline in the ability to learn that is associated with neuronal
death. Well known hallmarks of AD are neuritic plaques and neurofibrillary tangles and
extensive inflammation. Currently, no treatment has been developed to fully cure or prevent
the progression of dementia that is associated with AD.

AR1001 is being developed as a treatment for AD and shows great potential with favorable
attributes for a central nervous system (CNS) drug (i.e., high specificity and potency, as
well as good pharmacokinetic, bioavailability, CNS penetration, and ensured safety).

The clinical study of AR1001 aims to evaluate the efficacy and safety of AR1001 as a
potential treatment for AD. Based on the preclinical results, AR1001 could be an effective
treatment option with a mechanism of action that has not been explored for AD indication.

Inclusion Criteria:

1. Male or female subjects aged 55-75 years at the time of signing the Informed Consent
form.

2. Subjects (or subject's legally acceptable representative) and caregivers who can sign
an Informed Consent to participate in the study.

3. Subjects who have a diagnosis of probable mild-to-moderate Alzheimer's disease
according to the NINCDS-ADRDA (National Institute of Neurological and Communicative
Disorders and Stroke; Alzheimer's Disease and Related Disorders Association) criteria
at the screening and baseline visits.

4. Subjects who have an MMSE Score of 16-26 at the screening and baseline visits.

5. Subjects who have an MRI or CT scan performed within 12 months prior to screening with
findings consistent with the diagnosis of dementia due to Alzheimer's disease without
any other clinically significant comorbid pathologies.

6. Subjects who have one (or more) identified adult study partner(s) who, in the opinion
of the investigator, has sufficient contact with and knowledge about the subject as to
be able to report knowledgably about the subject's safety, compliance and adherence,
cognition, function, and behavior.

Exclusion Criteria:

1. Subjects who are female who are pregnant, nursing, or of childbearing potential and
not practicing effective contraception.

2. Subjects who have signs of delirium.

3. Subjects who have had cortical stroke within the preceding 2 years.

4. Subjects who have any diagnosis of dementia other than that related to Alzheimer's
Disease, including concomitant vascular dementia.

5. Subjects who have uncontrolled cardiac disease or hypertension.

6. Subjects who have clinically significant renal or hepatic impairment.

7. Subjects who have cancer or a malignant tumor, untreated thyroid disorder, or a
history of seizure disorder.

8. Subjects who are being treated, or likely to require treatment during the study, with
any medications prohibited by the study protocol.

9. Subjects who have received any investigational drug within the previous 30 days.

10. Subjects who have a clinically significant abnormal result in laboratory tests, as
determined by the Investigator.

11. Subjects with any current psychiatric diagnosis other than AD if, in the judgment of
the investigator, the psychiatric disorder or symptom is likely to confound
interpretation of drug effect, affect cognitive assessments, or affect the subject´s
ability to complete the study.

12. Subjects who have not been on a stable dose of anti-dementia therapy for at least 60
days prior to dosing, or intend to start anti-dementia therapy during the double-blind
portion of the study.

13. Subjects who currently take an alpha-1 blocker (e.g., tamsulosin).

14. Subjects who currently take any other phosphodiesterase type 5 (PDE-5) inhibitors.

15. Subjects who have known history, or suspected hypersensitivity to any excipients used
in the study.

16. Subjects with current use of nitrate agents.

17. Subjects who are currently receiving (or unable to stop use for at least 21 days [3
weeks] prior to receiving the first dose of the AR1001 and throughout the study)
prescription or non prescription medications or other products known to be moderate or
potent inhibitors/inducers of CYP3A4.

18. Subjects who have had any intake of grapefruit, grapefruit juice, Seville oranges,
Seville orange marmalade, or other products containing grapefruit or Seville oranges
within 7 days of the first administration of the AR1001 and throughout the study.

19. Subjects, in the opinion of the Investigator, who are unsuitable to participate in the
study.