Chemoimmunotherapy with low-dose fludarabine and cyclophosphamide and high dose rituximab in previously untreated patients with chronic lymphocytic leukemia.

Purpose: Chemoimmunotherapy combining fludarabine, cyclophosphamide, and rituximab (FCR) is an active regimen for untreated patients with chronic lymphocytic leukemia (CLL) with 70% complete responses (CRs) and 95% overall responses (ORs). However, grade 3/4 neutropenia was reported in 52% of cycles of treatment. The purpose of this trial was to maintain the high responses but reduce the toxicity of FCR by decreasing the fludarabine and cyclophosphamide (FCR-Lite).