A Phase 2 Study to Assess the Safety of EI-1071 and the Effects of EI-1071 on Neuroinflammation in Alzheimer's Disease Patients

Inclusion Criteria:

1. Must meet all the clinical criteria for mild to severe AD (i.e., probable orpossible AD dementia by NIA-AA criteria; must have objective evidence of cognitiveimpairment at Screening

2. Clinical Dementia Rating Scale (CDR)≧0.5

3. If using drugs to treat symptoms related to AD, doses must be stable for at least 8weeks prior to screening.

4. Adequate hematologic, hepatic, and renal function at the screening visit defined bythe following criteria:

• Absolute neutrophil count (ANC) ≥ 1.5 × 10⁹/L

• Hemoglobin [Hgb] > 10 g/dL

• Platelet count ≥ 100 × 10⁹/L

• Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 1 × upperlimit of normal (ULN)

• Total bilirubin and direct bilirubin ≤ 1.0 × ULN

• Alkaline phosphatase (ALP) ≤ 1.0 × ULN

• Creatinine clearance (CCr) ≥ 60 mL/min

5. Female subject with childbearing potential must have a negative serum pregnancy testat the screening visit (female subjects must be surgically confirmed sterile, i.e.,had hysterectomy, bilateral oophorectomy, or tubal ligation procedures),post-menopausal for at least 1 year (documented in the medical history), or mustcommit to use two contraceptive methods during the study.

6. Female subject with childbearing potential must be willing to implement adequate,highly effective contraceptive measure during the study period. Effective birthcontrol includes:

• Intrauterine device plus one barrier method

• Oral, implantable, or injectable contraceptives plus one barrier method; or

• Two barrier methods

• Effective barrier methods are male or female condoms, diaphragms, orspermicides (creams or gels that contain a chemical to kill sperm). Womenof childbearing potential are those who have not been surgicallysterilized or have not been free from menses for ≥ 1 year.

7. Male subject who agrees to use an adequate method of contraception during the studyperiod [e.g., barrier contraceptives (male condom)].

8. Subjects or his/her legal representative or guardian are willing to sign writteninformed consent and willing to comply with study requirements.

Exclusion Criteria:

1. Body weight ≥ 150 kg or body mass index (BMI) ≥ 35 kg/m² at the screening visit.

2. Prior use of pexidartinib (Turalio), other chemical entities, or any biologictreatment targeting colony stimulating factor 1 (CSF-1) or the CSF-1 receptor within 3-month of the first dose with EI-1071; previous uses of oral tyrosine kinaseinhibitors are allowed (e.g., imatinib or nilotinib).

3. AD patients with low binding affinity for tracer TSPO rs6971 SNP polymorphism atscreening

4. Pregnant, breast feeding or plan to be pregnant women during the study period

5. Active tuberculosis (TB), active or chronic infection with hepatitis B virus (HBV)or hepatitis C virus (HCV) or known active or chronic infection with humanimmunodeficiency virus (HIV) at screening or in the medical history.

6. Any medical or neurological/neurodegenerative condition (including mental deficit,intracranial tumor, glioma or meningioma; head trauma, Lewy body dementia; otherdisease than AD) that, in the opinion of the Investigator, might be a contributingcause to the participant's cognitive impairment or could lead to discontinuation,lack of compliance, interference with study assessments, or safety concerns

7. Clinically significant, unstable psychiatric illness or have contraindications tobrain magnetic resonance imaging (MRI) or PET scans

8. Have had a stroke or Transient Ischemic Attack (TIA), unexplained loss ofconsciousness or relevant brain hemorrhage, bleeding disorder and cerebrovascularabnormalities in the past year based on medical history (with MRI imaging results asconfirmation in the medical history) at screening. Subjects with clinically relevantcerebrovascular abnormalities in MRI will be excluded per PI's discretion.

9. Evidence of clinically significant gastrointestinal, cardiovascular, hepatic, renal,hematological, neoplastic, endocrine (including poor-controlled T2DM), neurological,immunodeficiency, pulmonary, or other disorder or disease at the screening visit (such as neurological or cognitive impairment/decline due to substance abuse,vitamin B12 deficiency, abnormal thyroid function, or other underlying conditionmight contribute to cognitive, functional or behavioral impairment will be excluded)by investigator's judgment at screening; subjects who have to be fed by enteral tubewill be excluded.

10. History of or ongoing malignancy or carcinoma (either concurrent or within the lastyear of starting study treatment) that requires therapy (e.g., surgical,chemotherapy, or radiation therapy), except for adequately treated basal or squamouscell carcinoma of the skin, melanoma in-situ, carcinoma in-situ of the cervix orbreast

11. Currently participating in any other clinical study or have participated in clinicaltrial within the last 60 days prior to screening; had donated blood (≥ 250 mL)within 30 days at screening.

12. Known allergy to EI-1071 or hypersensitivity to any component of the formulation (e.g., hydroxypropyl methylcellulose acetate succinate) or hypersensitivity to anyradiochemical tracer or [¹⁸F]FEPPA radiochemical tracer

13. Required to use strong inhibitors or inducers of cytochrome P450 3A4 (CYP3A4) and isanticipated to use these inhibitors or inducers during the study period