Inclusion Criteria:

- Patients with any relapsed or refractory hematological malignancy, for which standard
curative or life prolonging treatment does not exist, or is no longer effective or
tolerable.

- For the following hematological malignancies, patients must have received at least:

- Low grade NHL:

- 3 prior lines of therapy and ALL,

- aggressive NHL and other hematological malignancies:

- 2 prior lines of therapy.

- Ages 18 to 50 years and

- ECOG performance status of 0, 1 or 2,

- ability to understand and to sign a written informed consent and

- have a life expectancy of greater than or equal to 90 days

Exclusion Criteria:

- Any active CNS disease,

- previous greater than or equal to grade 3 allergic reaction to Erwinase,

- patients who have experienced a greater than or equal to grade 3 allergic reaction to
E. coli L-asparaginase and who have never received E. chrysanthemi L-asparaginase
after the occurrence of this reaction,

- WBC count greater than 20 Gica/L, any of the following laboratory abnormalities if
not due to hematologic malignancy (calculated creatinine clearance less than 50
mL/min,

- serum SGOT/AST or SGPT?ALT greater than 2.5 x upper limit of normal,

- serum total bilirubin greater than 2.0 mg/dL, except in the case of hemolytic anemia.

- Patients cannot have a history of greater than or equal to grade 2 pancreatitis,

- any history of allogeneic transplant,

- receiving steroid therapy with a dose greater than 20 mg/day,

- known HIV positive serology,

- active hepatitis B or C,

- any serious active disease or comorbid medical condition or psychiatric illness that
would prevent the subject from signing the informed consent.

- Pregnant or lactating females or women of child bearing potential not willing to use
an adequate method of birth control for the duration of the study are not eligible.