Treatment of chronic lymphocytic leukemia using chlorambucil and prednisone with or without cycle-active consolidation chemotherapy. A Southeastern Cancer Study Group Trial.

Patients with untreated chronic lymphocytic leukemia (CLL) received protocol treatment with 6 months of chlorambucil (CB) (30 mg/M2) and prednisone (P) (80 mg/d X 5) every 2 weeks. Complete and partial responders (CR, PR) were then randomized to consolidation with six more courses of CB and P or to four courses of cytosine arabinoside (25 mg/M2 every 12 hours X 8, subcutaneously) and cyclophosphamide (25 mg/M2 every 12 hours X 8, orally) every three weeks. Of the 178 eligible patients entered, 138 (78%) were evaluable for induction therapy which produced a 22% hematologic CR and an overall response rate (CR + PR) of 74%. Eighty-two patients received adequate consolidation, at the end of which 43 were in CR. No difference was seen in response or survival between the two consolidation treatments. Responders had longer survival than nonresponders (P = 0.0001) even when a 6-month "guarantee time" was excluded, but there was no survival difference between CR and PR. Thus, intermittent CB and P is a well-tolerated, useful therapy for CLL but the addition of cyclophosphamide and cytosine arabinoside does not improve results.