DISEASE CHARACTERISTICS:

• Histologically confirmed recurrent or refractory B-cell non-Hodgkin's lymphoma

  • CD20 positive
• Bidimensionally measurable or evaluable disease
• No myelodysplastic syndrome or chronic myeloid leukemia

PATIENT CHARACTERISTICS:

Age:

• 19 and over

Performance status:

• ECOG 0-2 OR
• Karnofsky 70-100%

Life expectancy:

• At least 3 months

Hematopoietic:

• WBC at least 3,000/mm3
• Granulocyte count at least 1,000/mm3
• Platelet count at least 100,000/mm3

Hepatic:

• Bilirubin no greater than 1.5 times upper limit of normal (ULN)
• AST or ALT no greater than 2.5 times ULN

Renal:

• Creatinine no greater than 1.5 mg/dL

Other:

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No other prior malignancy except curatively treated basal cell carcinoma, squamous cell carcinoma, or carcinoma in situ of the cervix
• No active serious infection
• No other concurrent serious medical condition that would preclude study

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• No prior bone marrow or peripheral blood stem cell transplantation for non-Hodgkin's lymphoma

Chemotherapy:

• No other concurrent chemotherapy

Endocrine therapy:

• No concurrent corticosteroids except transient administration as antiemetic
• Concurrent non-steroidal hormonal therapy allowed for non-disease related conditions (e.g., insulin for diabetes)

Radiotherapy:

• No concurrent radiotherapy

Surgery:

• Not specified

Other:

• No other concurrent investigational therapy
• No other concurrent antitumor agents