Abbreviated List of Eligibility Criteria

Inclusion Criteria:

- Patients must have relapsed or refractory acute lymphoblastic leukemia with a M3
marrow (marrow blasts >25%) who have had no more than two prior therapeutic attempts.

- Patients must have a history of prior systemic allergic reaction to E. coli
asparaginase (native or pegylated), such as urticaria, wheezing, or anaphylaxis.

- Patients may be in first or second relapse and should not have received more than 2
induction attempts.

- Patients must have less than 350mg/m2 lifetime exposure of anthracycline
chemotherapy.

- Patients should not have received previous therapy using Erwinase.

Exclusion Criteria:

- Patients with prior history of Grade 2 or greater asparaginase-induced symptomatic
pancreatitis will be excluded.

- Patients with a prior history of asparaginase associated stroke are excluded.

- Patients will be excluded if their shortening fraction by echocardiogram is less than
30%.

- Patients who are pregnant or nursing an infant.

LABS

- Direct bilirubin > 1.5x the institutional upper limit of normal for age. A total
bilirubin result that is less than 1.5 times the institutional upper limit of normal
for age may be used for eligibility if a direct bilirubin result is not available.

- SGPT (ALT) > 4 x institutional upper limit of normal

- Amylase or Lipase > 2 x institutional upper limit of normal

- Serum creatinine is > the upper limit of normal for age at the institution's
laboratory.