Inclusion Criteria

DISEASE CHARACTERISTICS:

- Morphologically proven acute lymphoblastic leukemia (ALL)

- Subtypes L1, L2, or L3

- Bone marrow morphology with greater than 25% lymphoblasts

- ALL morphology and cytochemistry with myeloid markers eligible

- Refractory to induction therapy or relapsed following chemotherapy or autologous
blood or bone marrow transplantation

- Any number of prior relapses allowed

- No relapse following allogeneic transplantation

- Prior CNS leukemia allowed if treated and currently disease-free

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- ECOG 0-2

Life expectancy:

- At least 6 months

Hematopoietic:

- Not specified

Hepatic:

- Bilirubin no greater than 2.0 mg/dL

- SGOT/SGPT no greater than 2 times upper limit of normal (ULN)

- Alkaline phosphatase no greater than 2 times ULN

Renal:

- Creatinine no greater than 2 mg/dL

Other:

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- No significant active infection

- No other medical conditions that would likely decrease life expectancy

- No other prior malignancy within the past 5 years except cured basal or squamous cell
skin cancer or carcinoma in situ of the cervix

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- See Disease Characteristics

Chemotherapy:

- See Disease Characteristics

Endocrine therapy:

- At least 2 weeks since prior systemic corticosteroids

Radiotherapy:

- Not specified

Surgery:

- Not specified

Other:

- No concurrent antibiotics for active or resolving infection