FCR-Lite, a drug regimen that consists of Fludara® (fludarabine), Cytoxan® (cyclophosphamide), and Rituxan® (rituximab), is highly effective in previously untreated patients with chronic lymphocytic leukemia (CLL) and produces significantly less grade 3-4 neutropenia than FCR, which uses higher doses of Fludara and Cytoxan. The results of this study were published in the Journal of Clinical Oncology.
Chronic lymphocytic leukemia (CLL) is the most common form of adult leukemia. The American Cancer Society estimates that approximately 8,000 people will be diagnosed with CLL this year. Currently, there are approximately 60,000 people in the United States living with CLL.
CLL is characterized by the production of atypical lymphocytes. Lymphocytes are specialized immune cells that exist in two forms: B- and T-cells. These cells are produced in the bone marrow and each serves a specific function in aiding the body fight infection.
The large majority of CLL cases involve mature B-lymphocytes that tend to live much longer than normal. B-lymphocytes accumulate in the blood, bone marrow, lymph nodes, and spleen. This results in overcrowding of these areas and suppression of the formation and function of blood and immune cells. Additionally, the cancerous lymphocytes themselves do not function normally, leading to a further reduction in the body’s ability to fight infection.
In previous studies the combination of Fludara, Cytoxan, and Rituxan (FCR) has been shown to produce a 95% overall response rate with 70% complete response; however, grade 3/4 neutropenia was reported in 52% of therapy cycles. FCR-Lite uses the same combination of drugs, but the doses of Fludara and Cytoxan are reduced, while the dose of Rituxan is increased. The goal is to reduce the toxicity associated with Fludara and Cytoxan yet still maintain high response to the therapy.
This study involved 50 previously untreated patients with CLL who were treated with six cycles of FCR-Lite given every four weeks. The overall response rate was 100% with a 77% complete response. The median duration of complete response was 22.3 months. Grade 3/4 neutropenia occurred in 13% of therapy cycles compared with 52% of therapy cycles in the previous study with FCR.
The researchers concluded that “FCR-Lite is highly effective in previously untreated CLL patients. Grade 3/4 neutropenia was dramatically reduced compared to standard FCR.”
 Foon KA, Boyiadzis M, Land SR, et al. Chemoimmunotherapy with low-dose fludarabine and cyclophosphamide and high dose rituximab in previously untreated patients with chronic lymphocytic leukemia. Journal of Clinical Oncology. 2009; 27:498-503.
 Keating MJ, O’Brien S, Albitar M, et al. Early results of a chemoimmunotherapy regimen of fludarabine, cyclophosphamide, and rituximab as initial therapy for chronic lympohcytic leukemia. Journal of Clinical Oncology. 2005; 23: 4079-4088.