DISEASE CHARACTERISTICS: Diagnosis of refractory chronic lymphocytic leukemia Evidence of active disease after fludarabine or alkylator therapy Must meet one or more of the following criteria for active disease: Minimum of one of the following disease-related symptoms: Weight loss of 10% or more within the previous 6 months Extreme fatigue (e.g., unable to work or perform usual activities) Fevers greater than 100.5 degrees F for 2 weeks or more without evidence of infection Night sweats without evidence of infection Evidence of progressive marrow failure manifested by the development or worsening of autoimmune anemia and/or thrombocytopenia that is poorly responsive to corticosteroid therapy Massive (e.g., greater than 6 cm below the left costal margin) or progressive splenomegaly Massive nodes or clusters (e.g., greater than 10 cm in longest diameter) or progressive lymphadenopathy Progressive lymphocytosis with an increase of more than 50% over a 2-month period or an anticipated doubling time of less than 6 months Ineligible if marked hypogammaglobulinemia or development of monoclonal protein in the absence of the above criteria for active disease Must have one of the following resulting from prior fludarabine or alkylator-containing therapy: Disease progression during therapy Failure to respond or obtained less than a partial response to therapy Disease progression within 6 months of the last course of therapy after an initial response Failure to respond or disease progression allowed at any time after the final dose if alkylator agent was not the most recent therapy