Fludarabine in comparison to alkylator-based regimen as induction therapy for chronic lymphocytic leukemia: a systematic review and meta-analysis.

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.