CHOP versus prednisolone + chlorambucil in chronic lymphocytic leukemia (CLL): preliminary results of a randomized multicenter study.

Five hundred and fifty consecutive patients with newly diagnosed B-CLL have been registered and classified in a Danish multicenter study. The study includes a protocol for primary treatment of patients in stage B or C (at diagnosis or after demonstrated progression), below 76 years of age, and without complicating serious disease. Until now 144 such patients have been randomized to either prednisolone (PRD) plus chlorambucil (CLB) 5 days every 4 weeks or monthly intensive CHOP treatment. Twenty-nine percent of the treated patients achieved CR on PRD + CLB versus 63% on CHOP (p less than 0.005). No response was found in 29% versus 18%, respectively (NS). A significant difference in survival between patients achieving CR, PR and NR was also demonstrated, whereas to date no difference in survival could be demonstrated between the two regimens. The toxicity was limited, and only 2 treatment-related deaths occurred in approximately 700 CHOP treatment series.