Safety and Efficacy of Allogeneic MSCs in Promoting T-regulatory Cells in Patients With Small Abdominal Aortic Aneurysms

This is a phase I, double blinded trial that will enroll 36 patients with Abdominal Aortic
Aneurysms (AAA) measuring 35-45 mm in maximal transverse diameter (MTD). This study will
assess the safety of MSCs in doses of 1 million MSCs/kg. or 3 million MSCs/kg. delivered
intra-venously. This trial test the hypothesis that MSCs, in a dose dependent fashion,
promote the frequency and immune suppressor function of CD4+CD25+ FoxP3+ T-regulatory cells
and decrease AAA inflammation as measured by 18-fluorodeoxyglucose positron emission
tomography/computed tomography (PET/CT). The primary safety endpoints will be incidence of
treatment related adverse events accrued over 24 months. Efficacy measures are changes in
frequency and immune suppressor function of Tregs, number and cytotoxic activity of CD4+/CD8+
CD28- T-cells, activated monocytes, and changes in aortic inflammation as measured by uptake
of 18-FDG PET/CT compared to baseline. Incidence of surgical intervention, aneurysm related
death, quality of life, and major adverse cardiac events will be recorded.

Inclusion Criteria:

- Be 40 and 85 years of age.

- Have diagnosis of non-inflammatory degenerative infrarenal abdominal aortic aneurysms
measuring 35-45 mm. in diameter by Computed Tomography (CT) scan.

- Females of childbearing potential must be willing to use one form of birth control for
the duration of the study. Female participants must undergo a blood or urine pregnancy
test at screening.

Exclusion Criteria:

- Inflammatory AAA defined by a thickened aortic wall and retroperitoneal fibrosis and
adhesions of peritoneal organs, and elevated erythrocyte sedimentation rate or in the
opinion of investigator.

- Mycotic AAA defined as saccular morphology, a positive blood culture, fever, or in the
opinion of the investigator.

- Symptomatic, Saccular, or any AAA associated with thoracic aorta dilatation >5.0 cm.

- Infra-renal AAA associated with Marfan's or Ehlers-Danlos Syndrome or other connective
tissue disorders.

- Common or external iliac artery aneurysm > 30 mm. in maximal transverse diameter.

- AAA due to dissection.

- Allergy to iodine contrast.

- History of cancer within the last 5 years, except basal cell skin carcinoma with clean
border pathology report.

- eGFR< 30mL/min.

- Any condition requiring immunosuppressant medications (e.g., for treatment of organ
transplants, psoriasis, Crohn's disease, alopecia areata, rheumatoid arthritis,
scleroderma, lupus).

- Acute coronary syndrome in the last 30 days prior to enrollment.*

- CHF hospitalization within the last 30 days prior to enrollment.*

- HIV or HCV positive, or active HBV.

- Contraindication to Computed Tomography or known allergy to contrast media.

- Any bleeding diathesis defined as an INR 2.0 (off anticoagulation therapy) or history
of platelet count less than 70,000 or hemophilia.

- Pregnant or breast feeding women.

- Significant hepatic dysfunction (ALT or AST greater than 2 times normal).

- Life expectancy less than two years.

- Inability to provide written informed consent due to cognitive or language barriers
(interpreter permitted).

- Presence of any clinical condition that in the opinion of the PI or the sponsor makes
the patient not suitable to participate in the trial.

- As defined by the standard definitions of CHF and ACS by the American Heart
Association.