Fludarabine and Thalidomide in Treating Patients With Newly Diagnosed Chronic Lymphocytic Leukemia

DISEASE CHARACTERISTICS: Confirmed diagnosis of B-cell chronic lymphocytic leukemia (CLL) based on the following criteria: Peripheral blood lymphocytosis > 5,000/mm^3 Co-expression of CD5, CD19 or CD20, and CD23 surface antigens Clonal kappa or lambda light chain expression No recurrent or refractory CLL No other lymphoproliferative diseases or diseases due to transformation of CLL, such as prolymphocytic leukemia or Richter's syndrome PATIENT CHARACTERISTICS: Age 18 and over Performance status Karnofsky 60-100% Life expectancy At least 12 weeks Hematopoietic See Disease Characteristics Hepatic Bilirubin < 1.5 mg/dL AST < 2.5 times upper limit of normal Renal Creatinine ≤ 1.5 mg/dL Cardiovascular No cardiac arrhythmia within the past 6 months No myocardial infarction within the past 6 months Other Not pregnant or nursing Negative pregnancy test Fertile patients must use at least 1 highly active and 1 additional method of contraception for 4 weeks before, during, and for at least 4 weeks after study treatment Patients must have sufficient mental capacity to understand the study explanation and provide informed consent No other malignancy within the past 5 years except basal cell skin cancer or carcinoma in situ of the cervix No active serious infection uncontrolled by antibiotics No medical condition or reason that would preclude study participation PRIOR CONCURRENT THERAPY: Biologic therapy Not specified Chemotherapy Not specified Endocrine therapy Not specified Radiotherapy Not specified Surgery Not specified Other No prior therapy for CLL