Bryostatin 1 Plus Cladribine in Treating Patients With Relapsed Chronic Lymphocytic Leukemia

DISEASE CHARACTERISTICS: * Diagnosis of relapsed chronic lymphocytic leukemia * Intermediate- or high-risk (stage I-IV) disease * Intermediate-risk patients must have active disease, defined by at least 1 of the following criteria: * Presence of any 1 of the following disease-related B symptoms: * 10% or more loss of body weight within the past 6 months * Extreme fatigue * Fever greater than 100 degrees Fahrenheit without evidence of infection * Night sweats * Massive (greater than 6 cm below left costal margin) or progressive splenomegaly * Massive (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 anticipated doubling time of less than 12 months * Progressive bone marrow failure as manifested by the development or worsening of anemia and/or thrombocytopenia * Autoimmune anemia and/or thrombocytopenia poorly responsive to corticosteroids * Failed 1-2 prior front-line regimens * Failed prior fludarabine * Ineligible for any known treatment of higher potential efficacy PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * Zubrod 0-2 Life expectancy: * At least 12 weeks Hematopoietic: * See Disease Characteristics * Absolute neutrophil count at least 1,000/mm\^3 * Platelet count at least 50,000/mm\^3 Hepatic: * Bilirubin less than 1.5 mg/dL * Transaminases less than 2.5 times normal Renal: * Creatinine less than 1.5 mg/dL OR * Creatinine clearance at least 60 mL/min Cardiovascular: * No history of severe coronary artery disease, cardiomyopathy, uncontrolled congestive heart failure, or arrhythmias Neurologic: * No prior drug-related neurotoxicity * No other neurologic disorder Other: * Not pregnant or nursing * Fertile patients must use effective barrier or non-hormonal contraception during and for 2 months after study participation * No HIV infection * No AIDS PRIOR CONCURRENT THERAPY: Biologic therapy: * No prior bone marrow transplantation Chemotherapy: * See Disease Characteristics * At least 4 weeks since prior chemotherapy (8 weeks for mitomycin or nitrosoureas) and recovered Endocrine therapy: * See Disease Characteristics * No concurrent steroids * No concurrent hormonal contraceptives Radiotherapy: * At least 4 weeks since prior radiotherapy and recovered Surgery: * Not specified Other: * No other concurrent therapy