FCR vs FC Improves Response Rates and Progression-Free Survival of Previously Untreated Patients With Advanced Chronic Lymphocytic Leukemia

Results from a multinational phase III clinical trial suggest that fludarabine, cyclophosphamide, and rituximab (FCR) chemoimmunotherapy may become the new standard first-line therapy for the treatment of advanced chronic lymphocytic leukemia. Michael Hallek, md, of the University of Cologne, Cologne, Germany, and German CLL Study Group, presented the study at the ASH meeting (abstract 325).

In this study, a total of 817 patients with previously untreated chronic lymphocytic leukemia were randomized to receive six 28-day cycles of FC (fludarabine, 25 mg/m2 intravenously on days 1 to 3, and cyclophosphamide, 250 mg/m2 intravenously on days 1 to 3) alone or FCR (375 mg/m2 intravenously at start of first cycle and 500 mg/m2 on day 1 for all subsequent cycles). The primary objective of the study was to determine response rates and progression-free survival.

Results at 2 Years
After an average follow-up of 25.5 months, a total of 761 patients were evaluable for response and 787 were evaluable for progression-free survival and overall survival. The overall response rate was significantly higher in the FCR arm (95%) as compared with the FC arm (88%). The complete response rate was also significantly higher in the FCR arm (52%) as compared with the FC arm (27%).

At 2 years, the progression-free survival rate was 76.6% in the FCR arm as compared with 62.3% in the FC arm. While FCR was found to cause more neutropenia (33.6% vs 20.9%) and leukopenia (24% vs 12.1%), it did not increase the incidence of severe infections (18.8% vs 14.8%) as compared with FC. Taken together, fludarabine, cyclophosphamide, and rituximab chemoimmunotherapy is a safe first-line treatment for chronic lymphocytic leukemia that improves response rates and progression-free survival, the investigators concluded.