Rituximab, Pentostatin, Cyclophosphamide, and Lenalidomide in Treating Patients With Previously Untreated B-Cell Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma

Cycle 1: 100 mg by IV on day 1, 375 mg/m\^2 by IV on day 2 Cycle 2-6: 375 mg/m\^2 by IV on day 1 (every 21 days)

600 mg/m\^2 by IV on day 1 of cycles 1-6 (every 21 days)

Cycle 7: 5 mg orally daily on days 1-28 Cycle 8: 10 mg orally daily on days 1-28 as tolerability permits Cycle 9 and beyond: 10 mg orally daily on days 1-28

2 mg/m\^2 by IV on day 1 of cycles 1-6 (every 21 days)