Inclusion Criteria:

- 18 years of age

- Histologically or cytologically documented relapsed or refractory acute leukemia

- Unlikely to benefit from standard therapy in the opinion of the investigator or
refuse standard therapy

- ECOG performance status 0-2

- Adequate renal and hepatic function

- No hematologic criteria for WBC, Hbg or platelets

- Negative virology screen for HIV, hepatitis B surface antigen & hepatitis C

- Female patients of childbearing potential must have a negative serum pregnancy test

- Male & female patients must agree to use a medically acceptable barrier and/or
chemical contraceptive method during the study and for a minimum of 3 months afte the
last dose of study treatment.

- Patients post blood or marrow transplant should demonstrate a circulating CD8 count
of at lest 200 cells/ul

Exclusion Criteria:

- Active CNS leukemia

- Current concomitant chemotherapy, radiation therapy or immunotherapy

- Receipt of any investigational agent within 28 days of first dose of JVRS-100

- Persistent clinically significant toxicity from prior anticancer therapy that is >
Grade 2 (NCI CTCAE v3.0)

- Bone marrow or stem cell transplant within 3 months prior to first dose of JVRS-100

- Chronic administration of immunosuppressive agents within 14 days of first dose of
JVRS-100. Use of inhaled steroids, nasal sprays, eye drops, and topical creams for
small body areas is allowed.

- Pregnant or lactating

- History of prior malignancy other than leukemia within the past 5 years, excluding
basal or squamous cell carcinoma of the skin or carcinoma in situ of the cervix

- Patients with a systemic fungal, bacterial, viral, or other infection not controlled

- Any condition which, in the opinion of the investigator, would compromise patient
safety or compliance, interfere with consent, study participation, follow up, or
interpretation of study results