Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed diffuse large B-cell non-Hodgkin's lymphoma (NHL)

- Relapsed or refractory after at least 1 regimen of standard therapy

- Prior therapy may include high-dose chemotherapy with autologous stem cell
transplantation (ASCT) or immunotherapy

- Bidimensionally measurable disease

- At least 1 lesion at least 1.5 cm by CT scan

- No primary or secondary CNS lymphoma

- No HIV-related lymphoma

- No known or suspected transformed lymphoma (prior or concurrent)

- No bulky disease (i.e., any single mass greater than 10.0 cm)

- No pleural effusion with positive cytology for lymphoma

- Most recent pathology specimen available for collection

- No rapid disease progression or symptoms that indicate disease progression requiring
rapid intervention within the past 2 weeks (e.g., severe shortness of breath, severe
pain, or gastrointestinal or genitourinary obstruction)

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- ECOG 0-2

Life expectancy

- At least 4 months

Hematopoietic

- Absolute neutrophil count at least 1,000/mm3

- Platelet count at least 50,000/mm3 (transfusion independent)

- Hemoglobin at least 9.0 g/dL

Hepatic

- Bilirubin no greater than 2 times upper limit of normal (ULN)

- AST and ALT less than 5 times ULN

- Hepatitis B surface antigen negative

- Hepatitis C negative

Renal

- Creatinine no greater than 2 times ULN

Other

- HIV negative

- No other primary malignancy within the past 3 years except squamous cell or basal
cell skin cancer, carcinoma in situ of the cervix, or stage I prostate cancer

- No other serious nonmalignant condition that would preclude study

- No serious infection

- No known human antichimeric antibodies or human antihuman antibody positivity

- No type 1 hypersensitivity or anaphylactic reactions to murine proteins

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception during and for at least 6 months
after study

PRIOR CONCURRENT THERAPY:

Biologic therapy

- See Disease Characteristics

- At least 4 weeks since prior immunotherapy (unless clearly progressing)

- At least 12 weeks since prior ASCT

Chemotherapy

- See Disease Characteristics

- At least 4 weeks since prior chemotherapy (unless clearly progressing)

Endocrine therapy

- Not specified

Radiotherapy

- No prior radioimmunotherapy

Surgery

- At least 4 weeks since prior major surgery (unless patient has fully recovered)

Other

- At least 30 days since prior enrollment in clinical trials involving investigational
devices or drugs

- No concurrent enrollment in other clinical trials involving investigational devices
or drugs

- No concurrent investigational agents for disease other than NHL