Effectiveness of "CHOP" regimen in advanced untreated chronic lymphocytic leukaemia. French Cooperative Group on Chronic Lymphocytic Leukaemia.

This paper gives the first interim results of a randomised clinical trial of several drug regimens for the treatment of chronic lymphocytic leukaemia. Patients were classified as being in stage A, B, or C depending on clinical findings and peripheral blood picture. Good prognosis patients--ie, stage A (n = 455)--were randomised to receive either no treatment or a course of chlorambucil. Intermediate prognosis patients--ie, stage B (n = 224)--received either chlorambucil or the COP regimen (cyclophosphamide, vincristine, and prednisone). Poor prognosis patients--ie, stage C (n = 60)--received either COP or CHOP (COP plus doxorubicin). The first six courses of polychemotherapy were given every month and the other six every 3 months. 93 deaths were recorded at the time of the analysis. Stages A and B patients did not show significant differences in survival rates between treatment groups. In stage C patients 2-year survival rates were 44% with COP and 77% with CHOP (p = 0.0013, one-sided log-rank test). Disease status, as assessed by staging at 9 months, was also better with CHOP than with COP. These results led to the termination of the trial and its replacement by one in which CHOP is given to intermediate prognosis patients.