RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die.

PURPOSE: Phase II trial to study the effectiveness of 506U78 in treating patients with recurrent or refractory hematologic cancer.

OBJECTIVES:

• Determine the response rate to compound 506U78 (2-amino-9-b-D-arabinofuranosyl-6-methoxy-9H-purine) administered as a 1 hour infusion daily for 5 days in patients with recurrent T-cell malignancies.
• Determine the toxicities of compound 506U78 in this group of patients.
• Correlate the biochemical pharmacology of compound 506U78 (e.g., ara-G nucleotides in leukemic blasts and CSF concentrations) with clinical response.
• Determine the impact of compound 506U78 therapy on survival and duration of response of patients with recurrent T-cell malignancies.

OUTLINE: Patients are stratified according to disease characteristics:

• Group 1: T-cell ALL or NHL in first relapse (greater than 25% bone marrow blasts, with or without concomitant extramedullary relapse other than CNS)
• Group 2: T-cell ALL or NHL in second or later relapse (greater than 25% bone marrow blasts, with or without concomitant extramedullary relapse other than CNS)
• Group 3: T-cell ALL or NHL with positive bone marrow and CSF (greater than 5% bone marrow blasts and CNS 2 or 3 involvement)
• Group 4: Extramedullary relapse and less than 25% blasts in the bone marrow (excluding isolated CNS relapse)

Group 1

• Patients receive a 1 hour infusion of compound 506U78 daily for 5 days in the absence of neurologic toxicity. The course repeats every 21 days. If a first relapse T-cell ALL study of higher priority is not open, then the patient may continue to receive the drug every 21 days for a maximum of 2 years provided that the patient has achieved a second complete response.

Groups 2 and 4

• Patients receive compound 506U78 every 21 days for a maximum of 2 years, in the absence of disease progression. After 3 courses a patient may be given CNS prophylaxis with triple intrathecal therapy (TIT), consisting of methotrexate, cytarabine and hydrocortisone after consultation with study coordinator. TIT should be given every 12 weeks.

Group 3

• Patients receive compound 506U78 every 21 days for a maximum of 2 years, in the absence of disease progression. TIT will be given on day 1 of weeks 1-4, 6, 9 and every 6 weeks for 12 weeks, and then every 9 weeks thereafter. This stratum is open.

PROJECTED ACCRUAL: A maximum of 148 patients (37 patients per stratum) will be accrued for this study.

DISEASE CHARACTERISTICS:

• Refractory or recurrent acute lymphocytic leukemia (ALL) or non-Hodgkin's lymphoma (NHL) with bone marrow involvement (T-cell disease only)
• Isolated CNS relapse not eligible

PATIENT CHARACTERISTICS:

Age:

• 21 and under

Performance status:

• Karnofsky 50-100%

Life expectancy:

• At least 8 weeks

Hematopoietic:

• Not specified

Hepatic:

• Bilirubin no greater than 1.5 mg/dL
• SGPT less than 5 times normal

Renal:

• Creatinine normal for age
• Creatinine clearance or GFR at least 60 mL/min/1.73m2

Other:

• No severe uncontrolled infection

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No concurrent biologic therapy

Chemotherapy:

• Recovered from toxic effects
• At least 6 weeks from administration of nitrosoureas

Endocrine therapy:

• No concurrent endocrine therapy

Radiotherapy:

• At least 6 weeks from administration of craniospinal or hemipelvic radiotherapy

Surgery:

• Not specified