Inclusion Criteria:

- Diagnosis of lymphoblastic lymphoma or acute lymphoblastic leukemia with ≥ 5% blasts
in the bone marrow (M2/M3) (with or without extramedullary disease) that meets 1 of
the following criteria:

- Refractory disease/induction failure (failure to achieve initial remission after
2 lines of induction therapy)

- Relapsed disease (in first relapse or higher)

- Central nervous system (CNS)-positive disease allowed

- Karnofsky performance status (PS) 50-100% (for patients ≥ 16 years of age) OR Lansky
PS 50-100% (for patients < 16 years of age)

- Life expectancy ≥ 8 weeks

- Creatinine clearance ≥ 70 mL/min OR maximum serum creatinine based on age/gender as
follows:

- 0.4 mg/dL (for patients 1 to 5 months of age)

- 0.5 mg/dL (for patients 6 to 11 months of age)

- 0.6 mg/dL (for patients 1 year of age)

- 0.8 mg/dL (for patients 2 to 5 years of age)

- 1.0 mg/dL (for patients 6 to 9 years of age)

- 1.2 mg/dL (for patients 10 to 12 years of age)

- 1.5 mg/dL (males) or 1.4 mg/dL (females) (for patients 13 to 15 years of age)

- 1.7 mg/dL (males) or 1.4 mg/dL (females) (for patients ≥ 16 years of age)

- ALT < 5 times upper limit of normal (ULN)

- Total bilirubin ≤ 1.5 times ULN for age

- LVEF ≥ 40% by ECHO/MUGA scan

- Shortening fraction > 29% by ECHO/MUGA scan

- Able to swallow capsules

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception during and for 2 months after
completion of study treatment

- No untreated positive blood cultures or progressive infections as assessed by
radiographic studies

- No known allergy to any of the agents or their ingredients used in this study

- Patients with clinically significant prior allergies to pegaspargase may be
treated with asparaginase-Erwinia, if available

- Patients who cannot receive asparaginase on this study (e.g., due to prior
pancreatitis, stroke, or other toxicity) are eligible provided they meet all other
inclusion/exclusion criteria

- Recovered from prior therapy (defined as CTCAE v3.0 toxicity ≤ grade 1)

- More than 3 weeks since prior chemotherapy for cancer other than hydroxyurea for
patients with WBC > 10,000/mm³

- At least 7 days since prior hematopoietic growth factors (14 days for pegfilgrastim)

- At least 1 month since prior biologic therapy, such as monoclonal antibodies

- At least 3 months since prior hematopoietic stem cell transplantation

Exclusion Criteria:

- Evidence of graft-versus-host disease

- Concurrent valproic acid

- Concurrent coumadin/warfarin other than a short course administered in a prophylactic
setting