Erwinaze will be administered intravenously at a dose of 25,000 IU/m2 (dose cohort 0) for 6 doses MWF over a period of 2 weeks to 9 patients (as described below and in the following schema). Blood counts, chemistries including bilirubin, amylase and lipase, and coagulation studies including fibrinogen will be measured and reviewed before each asparaginase dose. Fibrinogen (<100 mg/dL) can be replaced with cryoprecipitate before each dose at the discretion of treating physician. Treatment will be stopped for elevation of amylase, lipase or direct bilirubin above normal range.

For safety:

Erwinaze has been already used in clinical practice for treatment of patients with acute leukemia with known side effect profile. For this reason, in this protocol, we use the "3+3+3" design for evaluation of safety based on pre-determined dose-limiting toxicities (DLT). In the "3+3+3" design, the dose escalation rules proceed by adjusting the dose in cohorts of 3 to 9 patients per three dose levels:20,000 IU/m2 (dose cohort -1), 25,000 IU/m2 (dose cohort 0), 30,000 IU/m2 (dose cohort +1). The goal is to determine the Recommended Phase 2 Dose (RP2D)

For anti-leukemic activity:

To evaluate the activity of Erwinaze to reduce the serum glutamine to the desired level, the dose will be adjusted according to a pre-defined algorithm based on 48-hour trough serum glutamine level (biochemical response) prior to dose 6 of each patient. If the safety profile is acceptable, we will enroll up to a total of 15 patients at that dose level to better study and analyze the glutamine-reducing effect of Erwinaze at the defined dose.

In summary, if 9 patients are treated at a certain dose and at least 7 out of 9 individuals respond to treatment (per serum glutamine levels) and < 3 develop DLT, this dose level will be declared the Recommended Phase 2 Dose (RP2D). Six additional patients (total of 15 to 18 patients) will be enrolled at the RP2D level to better assess toxicity and to document responses.

There will be no intra-patient dose escalation or reduction.

Inclusion Criteria:

• Histologically or cytologically confirmed AML
• 18 years and older
• AML has relapsed after, or is refractory to, first-line therapy, with or without subsequent additional therapy
• Have received or are ineligible for immediate established curative regimens
• ASCT patients are eligible provided that they are >= 4 weeks from stem cell infusion
• alloSCT patients are eligible if they are >= 60 days post stem cell infusion, have no evidence of graft versus host disease (GVHD) > Grade 1, and are >= 2 weeks off all immunosuppressive therapy
• Previous cytotoxic chemotherapy completed at least 3 weeks and radiotherapy at least 2 weeks prior to day 1 of study treatment
• Biologic agents stopped at least 1 week prior to day 1 of study treatment
• DNA methyltransferase inhibitors stopped at least 3 weeks prior to day 1 of study treatment
• ECOG performance status ≤2
• Patients must have normal organ function
• Female patients of childbearing potential must have a negative pregnancy test.
• Ability to understand and willingness to sign a written informed consent document.

Exclusion Criteria:

• Patients receiving any other investigational agents, or concurrent chemotherapy, radiation therapy, or immunotherapy
• Patients with acute promyelocytic leukemia
• Patients with active central nervous system leukemia
• Prior treatment with Erwinaze
• Hyperleukocytosis with > 50,000 blasts/μL
• History of a major thrombotic event
• History of pancreatitis
• Active, uncontrolled infection
• Uncontrolled intercurrent illness
• Pregnant women
• Uncontrolled active seizure disorder or a history of seizure