Fludarabine and Cyclophosphamide With or Without Oblimersen in Treating Patients With Relapsed or Refractory Chronic Lymphocytic Leukemia

RATIONALE: Drugs used in chemotherapy use different ways to stop cancer cells from dividing so they stop growing or die. Oblimersen may help fludarabine and cyclophosphamide kill more cancer cells by making them more sensitive to the drugs. It is not yet known if fludarabine and cyclophosphamide are more effective with or without oblimersen. PURPOSE: Randomized phase III trial to compare the effectiveness of fludarabine and cyclophosphamide with or without oblimersen in treating patients who have relapsed or refractory chronic lymphocytic leukemia.