Study of QUAIL-100 in Patients With High Risk Acute Leukemia and Myelodysplastic Syndrome Who Have Received Hematopoietic Stem Cell Transplant

Inclusion Criteria:

• Weight >/= 10 kg
• Have received HLA-partially matched related or unrelated donor ab-depleted hematopoietic stem cell transplant (HSCT) for high-risk malignant disease and has achieved myeloid and platelet engraftment
• Lanksy/Karnofsky score > 60
• Participants of childbearing potential must agree to use contraception to prevent pregnancy

Exclusion Criteria:

• Active Grade II acute graft versus host disease (aGVHD) requiring > 0.5 mg/kg methylprednisolone or any diagnosis of Grade III/IV aGVHD
• Significant cardiac, pulmonary, renal, hepatic, GI, neurological or immunological disease that could compromise safe participation
• Known allergies, hypersensitivity or intolerance to both amoxicillin and gentamycin
• Implanted medical devices with high potential for bacterial seeding, including pacemakers, artificial cardiac valves, prosthetic joints, orthopedic plates or screws, atrial appendage or inferior vena cava devices for thrombosis prevention
• Planned anti-leukemic therapy within 21 days of planned dosing
• Use of tumor necrosis factor (TNF) a or phosphatidylinositol 3-kinase (PI3K) inhibitors within 60 days of screening
• Any prior investigational Listeria product including QUAIL-100
• Live, attenuated vaccine within 4 weeks of first dose