RATIONALE: Drugs used in chemotherapy 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 block the ability of cancer cells to grow and spread. Others find cancer cells and help kill them or carry cancer-killing substances to them. Giving more than one drug (combination chemotherapy) together with rituximab may kill more cancer cells.

PURPOSE: This phase II trial is studying how well giving combination chemotherapy together with rituximab works in treating patients with chronic lymphocytic leukemia (CLL) that has not responded to fludarabine (closed to entry as of 10/2006), CLL with autoimmune hemolytic anemia, or Richter transformation.

OBJECTIVES:

Primary

• Determine the efficacy, in terms of the rate and quality of remission, of chemotherapy comprising cyclophosphamide, doxorubicin hydrochloride, vincristine, prednisone, and rituximab (CHOP-R) in patients with fludarabine-refractory chronic lymphocytic leukemia (CLL) (closed to accrual as of 10/2006), CLL with autoimmune hemolytic anemia, or Richter transformation.
• Determine the incidence of infection in patients on CHOP-R regimen.

Secondary

• Determine the toxicity of this regimen in these patients
• Determine the progression-free and overall survival of patients treated with this regimen.

OUTLINE: This is a prospective, multicenter study. Patients are stratified according to disease (chronic lymphocytic leukemia (CLL) (closed to accrual as of 10/2006) vs CLL with autoimmune hemolytic anemia vs Richter transformation).

Patients receive cyclophosphamide IV, doxorubicin hydrochloride IV, and vincristine IV on day 1 and oral prednisone on days 1-5. Patients also receive rituximab IV on day 1 of the second course and each subsequent course. Treatment repeats every 21 days for up to 6 (for patients with CLL) or 8 (for patients with Richter's transformation) courses in the absence of disease progression or unacceptable toxicity.

PROJECTED ACCRUAL: A total of 75 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Confirmed diagnosis of previously treated chronic lymphocytic leukemia (CLL) meeting the following criteria:

  • Binet stage B (Rai stages I and II) or Binet stage C (Rai stages III and IV) disease
  • Rapid disease progression, symptomatic enlarged lymph nodes, or severe B-cell symptoms

• CLL with autoimmune hemolytic anemia allowed

• Richter transformation allowed

PATIENT CHARACTERISTICS:

• Life expectancy > 3 months
• ECOG performance status 0-3
• No severe organ dysfunction
• No other prior or concurrent neoplasms

PRIOR CONCURRENT THERAPY:

• No more than 4 prior chemotherapy regimens