Inclusion Criteria

DISEASE CHARACTERISTICS:

- One of the following histologically or cytologically confirmed diseases:

- Indolent B-cell non-Hodgkin's lymphoma (NHL)

- Stage II-IV disease

- Chronic lymphocytic leukemia (CLL) meeting 1 of the following risk criteria:

- Intermediate-risk with progressive disease

- High-risk, modified Rai stage disease

- CD20-positive by flow cytometry or immunohistochemistry

- Measurable disease

- Rituximab-refractory disease, defined as failure to achieve a response to the last
course of prior treatment with rituximab alone or in combination with other
therapeutic modalities

- No known neoplastic leptomeningeal involvement and/or brain metastases

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- ECOG 0-2 OR

- Karnofsky 60-100%

Life expectancy

- More than 3 months

Hematopoietic

- Absolute neutrophil count ≥ 1,500/mm^3

- Platelet count ≥ 50,000/mm^3

- WBC ≥ 3,000/mm^3

Hepatic

- AST and ALT ≤ 2.5 times upper limit of normal

- Bilirubin normal (unless due to Gilbert's disease or organ involvement by NHL or CLL)

Renal

- Creatinine normal OR

- Creatinine clearance ≥ 60 mL/min

Cardiovascular

- No symptomatic congestive heart failure

- No unstable angina pectoris

- No cardiac arrhythmia

Other

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- HIV negative

- No history of anaphylaxis or immunoglobulin (Ig) E-mediated hypersensitivity to
murine protein

- Prior infusion reactions to rituximab without an IgE component allowed

- No active or ongoing infection

- No psychiatric illness or social situation that would preclude study compliance

- No other uncontrolled illness

PRIOR CONCURRENT THERAPY:

Biologic therapy

- See Disease Characteristics

- See Radiotherapy

- At least 12 weeks since prior rituximab

- More than 4 weeks since prior immunotherapy and recovered

Chemotherapy

- No more than 3 prior chemotherapy regimens

- More than 4 weeks since prior chemotherapy and recovered

Endocrine therapy

- No concurrent glucocorticoids

Radiotherapy

- At least 12 weeks since prior radioimmunotherapy

- More than 4 weeks since prior radiotherapy and recovered

Surgery

- Not specified

Other

- At least 4 weeks since prior therapy for the malignancy

- No other concurrent anticancer therapy

- No other concurrent investigational agents