Randomized Phase III Trial of Fludarabine Plus Cyclophosphamide With or Without Oblimersen Sodium (Bcl-2 antisense) in Patients With Relapsed or Refractory Chronic Lymphocytic Leukemia

Purpose Expression of Bcl-2 protein is associated with chemotherapy resistance and decreased survival in chronic lymphocytic leukemia (CLL). We evaluated whether oblimersen would improve response to chemotherapy in patients with relapsed or refractory CLL. Patients and Methods Patients had received at least one prior fludarabine-containing regimen and were stratified on the basis of prior fludarabine response, number of prior regimens, and duration of response to last prior therapy. Patients were randomly assigned to 28-day cycles of fludarabine 25 mg/m2/d plus cyclophosphamide 250 mg/m2/d administered intravenously for 3 days with or without oblimersen 3 mg/kg/d as a 7-day continuous intravenous infusion (beginning 4 days before chemotherapy) for up to six cycles. The primary end point was the proportion of patients who achieved complete response (CR) or nodular partial response (nPR). Results Of 241 patients randomly assigned, CR/nPR was achieved in 20 (17%) of 120 patients in the oblimersen group and e...