RATIONALE: Monoclonal antibodies such as epratuzumab can locate tumor cells and either kill them or deliver tumor-killing substances to them without harming normal cells.

PURPOSE: Randomized phase II trial to study the effectiveness of epratuzumab in treating patients who have non-Hodgkin's lymphoma.

OBJECTIVES:

• Determine the response rate of patients with diffuse large B-cell non-Hodgkin's lymphoma treated with epratuzumab.
• Determine the toxicity of this drug in these patients.

OUTLINE: This is a randomized, multicenter study. Patients are randomized to 1 of 3 treatment arms.

• Arm I: Patients receive low-dose epratuzumab IV over 1 hour once weekly for 4 weeks.
• Arm II: Patients receive low-dose epratuzumab IV over 1 hour once weekly for 8 weeks.
• Arm III: Patients receive high-dose epratuzumab IV over 1 hour once weekly for 4 weeks.

Patients are followed every 3 months for 2 years and then every 6 months thereafter.

PROJECTED ACCRUAL: A total of 150 patients (50 per treatment arm) will be accrued for this study.

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