Pentostatin, Alemtuzumab, and Rituximab in Treating Patients With Relapsed or Refractory Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) meeting the following criteria:
• Minimum threshold peripheral blood lymphocyte count of 5 x 10^9/L (CLL variant) OR adenopathy > 1 cm or palpable splenomegaly (SLL variant)
• Immunophenotypic demonstrations of a population of B lymphocytes (as defined by CD19+) that are monoclonal (by light chain exclusion) AND have ≥ 3 of the following characteristics:
• CD5+
• CD23+
• Dim surface light chain expression
• Dim surface CD20 expression
• FISH analysis is negative for IGH/CCND1 and/or immunostaining is negative for cyclin D1 expression
• Must have progressive disease as indicated by any of the following characteristics (based on standard criteria for treatment):
• Symptomatic CLL characterized by any of the following:
• Weight loss > 10% within the past 6 months
• Extreme fatigue
• Fevers > 38.5° C (not due to infection)
• Drenching night sweats without evidence of infection
• Evidence of progressive bone marrow failure with hemoglobin 6 cm below left costal margin)
• Massive (> 10 cm) or rapidly progressive lymphadenopathy

PATIENT CHARACTERISTICS:

• ECOG performance status 0-3
• Creatinine ≤ 2 times upper limit of normal (ULN)
• Total bilirubin ≤ 3.0 times ULN OR direct bilirubin ≤ 1.5 times ULN
• AST ≤ 3.0 times ULN (unless due to hemolysis or CLL)
• Willing to provide mandatory blood samples for research studies
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for up to 12 months after completion of study treatment
• No other active primary malignancy that requires treatment or limits survival to ≤ 2 years
• No active autoimmune hemolytic anemia, immune thrombocytopenia, or pure red blood cell aplasia
• No New York Heart Association class III or IV heart disease
• No myocardial infarction within the past month
• No uncontrolled infection
• No HIV infection or AIDS
• No active hepatitis B infection (i.e., HBsAg or HBeAg positivity) or hepatitis C infection by serology
• No other comorbid condition

PRIOR CONCURRENT THERAPY:

• No more than 3 prior treatment regimens for CLL that included purine analogue drugs (e.g., fludarabine, pentostatin, or cladribine) OR previously untreated CLL in patients with high-risk disease due to 17p13 deletion on FISH analysis
• More than 4 weeks since prior major surgery
• More than 2 months since prior alemtuzumab
• Prior corticosteroids allowed
• No concurrent continuous systemic corticosteroids