Fludarabine in Comparison to Alkylator-based Regimen as Induction Therapy for Chronic Lymphocytic Leukemia: A Systematic Review and Meta-analysis

Abstract
The superiority of Fludarabine over conventional therapy as primary induction therapy for patients with chronic lymphocytic leukemia (CLL) has been shown in several studies but no studies have yet reported a pooled estimate of the treatment effect. We performed a systematic review of evidence from 5 randomized controlled trials involving approximately 1300 patients with CLL, comparing Fludarabine with several alkylator-based combination regimens in the primary treatment of CLL. Complete response rate was significantly higher for Fludarabine compared to alkylator-based chemotherapy (RR 1.87, 95% CI 1.10-3.19, P=0.02), while overall response, though superior, did not reach statistical significance (RR 1.22, 95% CI=0.88-1.69, P=0.24). Overall survival was similar for Fludarabine and alkylator-based therapy (the pooled log hazard ratio of death, HR=-0.05, 95% CI=-0.36-0.26, P=0.75). Infection rate was significantly higher (RR 1.58, 95% CI=1.10-2.27, P=0.01), but there was no significant difference in the incidence of thrombocytopenia, neutropenia and anemia. Therefore, this meta-analysis supports the findings that Fludarabine as an induction agent for patients with CLL yields a better clinical response with acceptable toxicity when compared with alkylator-based combination therapy, but without a survival benefit by 5-6 years of follow up.