A Phase II Study Of Anti-CD20 Monoclonal Antibody (Rituximab) Therapy For Patients With Refractory Or Relapsed Primary CNS Lymphoma (PCNSL)

Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed primary CNS lymphoma based on 1 of the following:

- Histologically confirmed non-Hodgkin's B-cell lymphoma by brain biopsy or
resection

- Positive cerebrospinal fluid (CSF) cytology or immunohistochemical diagnosis of
CSF monoclonality with or without measurable intracranial disease

- Histologically confirmed vitreal lymphoma with measurable intracranial tumor

- CD20 positive by brain biopsy

- Measurable (greater than 1 cm in diameter) tumor by CT scan or MRI

- Progressed during first-line chemotherapy and/or radiotherapy OR relapsed after
initial successful treatment

- No systemic lymphoma by CT scan of the chest, abdomen, and pelvis with contrast

- No leptomeningeal lymphoma by lumbar puncture for CNS cytology/flow cytometry

- No ocular lymphoma by slit lamp examination

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- Karnofsky 60-100%

Life expectancy

- Not specified

Hematopoietic

- Absolute neutrophil count at least 1,500/mm^3

- Platelet count at least 100,000/mm^3

- Hemoglobin at least 9.0 g/dL

Hepatic

- Bilirubin less than 1.5 mg/dL

- Transaminases less than 4 times upper limit of normal

Renal

- Creatinine less than 1.5 mg/dL

Other

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception during and for 1 year after study
participation

- HIV negative

- Mini mental status examination score at least 15

- No concurrent serious infection

- No other medical illness that would preclude study treatment

- No other malignancy within the past 5 years except curatively treated basal cell or
squamous cell skin cancer or carcinoma in situ

PRIOR CONCURRENT THERAPY:

Biologic therapy

- More than 90 days since prior biologic therapy

- No prior rituximab

- No concurrent prophylactic growth factors (e.g., filgrastim [G-CSF] or sargramostim
[GM-CSF])

Chemotherapy

- See Disease Characteristics

- At least 3 weeks since prior chemotherapy (6 weeks for nitrosoureas)

Endocrine therapy

- Not specified

Radiotherapy

- See Disease Characteristics

- At least 3 months since prior radiotherapy

Surgery

- Not specified

Other

- Recovered from prior therapy

- More than 90 days since prior investigational drugs

- More than 90 days since prior use of a therapeutic device