Treatment of chronic lymphocytic leukemia in advanced stages. A randomized trial comparing chlorambucil plus prednisone versus cyclophosphamide, vincristine, and prednisone.

Ninety-six patients with advanced chronic lymphocytic leukemia (CLL) (Stage C; anemia and/or thrombocytopenia of nonimmune origin) were randomized to receive either chlorambucil (CLR) (0.4 mg/kg orally, day 6) plus prednisone (PDN) (60 mg/m2 orally, days 1-5) every 2 weeks or cyclophosphamide (600 mg/m2 intravenously, day 6), vincristine (1 mg/m2 intravenously, day 6) and prednisone (60 mg/m2 orally, days 1-5) (COP) each month for 5 months. Complete remission (CR) was defined as the total disappearance of signs and symptoms related to the disease. Partial remission (PR) was considered to be achieved when, after treatment, the clinical stage changed to a less advanced one. Thirty (59%) responses (8% CR) with CLR plus PDN and 14 (31%, 2% CR) with COP were observed (P less than 0.01). The survival was not significantly different for the two groups. Patients previously treated had a lower number of responses (11/35, 31%) than those with no previous treatment (33/61, 54%) (P less than 0.05). Patients who attained a CR or a good PR had longer survivals (median not reached) than those with a poor PR (median, 25.2 months) or those who did not respond to treatment (median, 11.5 months) (P less than 0.005).