RATIONALE: Drugs used in chemotherapy, such as fludarabine and cyclophosphamide, work in different ways to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. Monoclonal antibodies, such as rituximab, can block cancer growth in different ways. Some find cancer cells and kill them or carry cancer-killing substances to them. Others interfere with the ability of cancer cells to grow and spread. Giving fludarabine and cyclophosphamide together with rituximab may kill more cancer cells.

PURPOSE: This phase II trial is studying how well giving fludarabine and cyclophosphamide together with rituximab works in treating patients with B-cell prolymphocytic leukemia.

OBJECTIVES:

• Determine the overall and progression-free survival of patients with B-cell prolymphocytic leukemia treated with immunochemotherapy comprising fludarabine, cyclophosphamide, and rituximab.
• Determine the toxic effects of this regimen in these patients.

OUTLINE: This is a non-randomized, open-label, multicenter study.

Patients receive fludarabine IV and cyclophosphamide IV on days 1-3. Patients also receive rituximab IV on day 0 in course 1 and on day 1 in courses 2-6. Treatment repeats every 28 days for up to 6 courses.

PROJECTED ACCRUAL: A total of 21 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Diagnosis of B-cell prolymphocytic leukemia

  • Previously treated disease

• All Binet stages allowed

PATIENT CHARACTERISTICS:

• Life expectancy > 3 months
• ECOG/WHO performance status 0-3

PRIOR CONCURRENT THERAPY:

• No more than 3 prior treatment regimens