The purpose of this study is to evaluate safety and target engagement of XPro1595 in Alzheimer's patients with biomarkers of inflammation.

The study is designed as a multicentre, phase 1b open-label study. The objectives of this study are to determine the safety, tolerability, and efficacy of XPro1595 in patients with Alzheimer's disease and at least one of the following inflammatory biomarkers: high sensitivity c-reactive protein (hs-CRP), hemoglobin A1c, erythrocyte sedimentation rate (ESR), or one Apolipoprotein E4 allele.

XPro1595 is a second-generation inhibitor of tumor necrosis factor (TNF) that selectively neutralizes soluble TNF, an inflammatory factor implicated in Alzheimer's pathology.

A key element of this study is to identify Alzheimer's patients that are most likely to benefit from XPro1595 treatment. Enrollment is limited to patients with evidence of inflammation. For instance, hs-CRP is an inflammatory biomarker elevated in the blood of some Alzheimer's patients and elevated CRP has been shown to predict response to TNF inhibitors in multiple other diseases.

Alzheimer's patients with elevated inflammatory biomarkers will be enrolled in a 12-week study to determine the safety and the ability of XPro1595 to reduce neuroinflammation using a combination of invasive and non-invasive biomarkers of inflammation. The study will identify the dose of XPro1595 to be used in a larger Phase II disease modification study.

Inclusion Criteria:

1. Aged 18 years and above at screening;
2. Diagnosed with probable AD defined by the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria;
3. Has hsCRP levels ≥1.5mg/L,OR HbA1c ≥ 6DCCT %, OR Erythrocyte Sedimentation Rate (ESR) ≥10 mm/h, OR APOE4 positive (at least one APOE4 allele);
4. Female of childbearing potential (FCBP) must have confirmed negative urine pregnancy test at Screening;
5. All female of childbearing potential (FCBP) and male patients who are sexually active with a female of childbearing potential must agree to use a highly effective contraception during the treatment period and until 90 days after the last dose of treatment for sexually active males whose partners are FCBP or until 30 days after the last dose of treatment for FCBP.
6. Consents to having lumbar punctures;
7. Consents to apolipoprotein E (APOE) genotyping(if status unknown);
8. Provide written informed consent prior to any study procedures being performed;
9. Has a caregiver who either lives in the same household or interacts withthe patient at least 4 hours per day and at least 4 days per week, who is knowledgeable about the participant's daytime and night-time behaviours and who canbe available to attend all clinic visits in personat which caregiver assessments are performed.Patients with caregivers that do not meet this criterionbut are determined by the investigator as able to provide an adequate assessment of the patient may also participate with prior approval from the sponsor.

Exclusion Criteria:

1. Patients taking cholinesterase inhibitors, memantine, or antidepressant medication for less than 45 days from Day 1 (i.e. must be on stable dose for at least 45 days prior to Day 1);
2. Have taken within the last 45 days from Day 1; corticosteroids or other immunosuppressive drugs, thalidomide or other TNF active drugs, minocycline.
3. Enrolled in another clinical trial where patients receive treatment with investigational drug or device or have received treatment on another AD clinical trial within the last 60 days from Day 1;
4. Unable to tolerate lumbar puncture or taking medicine where lumber punctures are contraindicated (anti-coagulants besides daily 100mg of aspirin);
5. A prior organ or stem cell transplant;
6. A major adverse cardiac event within 6 months before screening;
7. Lymphoma, leukaemia, or any malignancy within the past 5 years with the exception of malignancies with negligible risk of metastasis or death, such as basal cell or squamous cell carcinomas of the skin or cervical carcinoma in situ that have been resected with no evidence of metastatic disease for 3 years;
8. Jaundice, active hepatitis, or known hepatobiliary disease (except asymptomatic cholelithiasis);
9. Positive screening assessment for viral hepatitis B surface antigen or hepatitis C virus (HCV) antibody and positive HCV ribonucleic acid or human immunodeficiency virus, or a history of illicit drug injecting;
10. Seated blood pressure of ≥ 165/105 mmHg at screening;
11. Unable to comply with the study procedures and assessments;12.Known hypersensitivity to investigational product or its excipients;