Treatment of Chronic Lymphocytic Leukemia: A Preliminary Report of Spanish (Pethema) Trials.

In 1988 the Spanish Cooperative Group PETHEMA initiated a series of trials in CLL patients stratified according to their clinical stage. Patients in stage A were allocated to treatment with intermittent chlorambucil plus prednisone or observation, in order to investigate whether treatment is of benefit; patients in stage B received chlorambucil alone or chlorambucil plus prednisone, the objective being to ascertain the contribution, if any, of prednisone to that combination; finally, patients in stage C received chlorambucil plus prednisone or mini-CHOP, to try to reproduce previously reported results. In this first interim analysis no survival advantage was observed for patients in stage A receiving treatment (n = 36) (projected survival 95% at 3 years) as compared to those not treated (n = 44) (projected survival: 100% at 3 years); this trial has recently been cancelled. In stage B no differences in either response rate and survival were observed between patients treated with chlorambucil alone (n = 23) (response rate; 56.5%; projected survival: 90% at 3 years) and chlorambucil plus prednisone (n = 20) (response rate: 60%; projected survival: 80 at 3 years). Finally, in stage C 14 evaluable patients treated with mini-CHOP had a response rate (50%) not different from that obtained in 19 patients treated with chlorambucil plus prednisone (42%) and no significant differences in survival between both groups (60% and 85% at 3 years, respectively) are observed. A meaningful analysis of these trials will require a larger number of patients and a longer follow-up.