Rituximab in Treating Patients With Refractory or Relapsed Primary CNS Lymphoma

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

PURPOSE: Phase II trial to study the effectiveness of rituximab in treating patients who have refractory or relapsed primary CNS lymphoma.

OBJECTIVES:

Primary

* Determine the radiographic response proportion in patients with refractory or recurrent primary CNS lymphoma treated with rituximab.

Secondary

* Determine the progression-free and overall survival of patients treated with this drug.
* Determine the toxicity profile of this drug in these patients.

OUTLINE: This is a multicenter study.

Patients receive rituximab IV on days 1, 8, 15, and 22. Treatment repeats every 28 days for 2 courses in the absence of disease progression or unacceptable toxicity. Patients may receive additional courses of rituximab off study at the discretion of the treating physician.

Patients are followed every 2 months.

PROJECTED ACCRUAL: A total of 15-25 patients will be accrued for this study within 5-9 months.

Eligibility 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