DISEASE CHARACTERISTICS: Relapsed or refractory chronic lymphocytic leukemia (CLL) Previously treated with alkylating agent Refractory or intolerant to fludarabine as defined by: Progressive disease during treatment with fludarabine Stable disease (no partial or complete response) after at least 2 courses of fludarabine Relapse or progressive disease within 6 months of treatment with fludarabine Autoimmune hemolytic anemia or idiopathic thrombocytopenia concurrent with or within 1 month after completion of fludarabine Grade 2 pulmonary toxicity or neurotoxicity that would preclude further treatment with fludarabine OR Progressive B-cell CLL as defined by at least 1 of the following: Hemoglobin less than 11 g/dL, or progressive decline Platelet count no greater than 100,000/mm3, or progressive decline Massive (greater than 6 cm below costal margin) or progressive splenomegaly Massive lymph nodes or clusters or progressive lymphadenopathy At least 10% weight loss in past 6 months Fatigue grade 2-3 Fever (greater than 100.5 F) or night sweats for greater than 2 weeks without evidence of infection Progressive lymphocytosis greater than 50% over 2 month period, or anticipated doubling time less than 6 months Lymphocyte count greater than 100,000/mm3 No uncontrolled autoimmune hemolytic anemia or idiopathic thrombocytopenia No other uncontrolled immune phenomena related to CLL No CNS metastases