According to results recently presented at the 2006 annual meeting of the European Society for Medical Oncology (ESMO), the chemotherapy combination referred to as XELOX is as effective as FOLFOX, though more convenient, as initial therapy for metastatic colorectal cancer. Furthermore, the addition of Avastin® (bevacizumab) to either treatment regimen improves progression-free survival among these patients.
Colorectal cancer remains the second leading cause of cancer-related death in the United States. Metastatic colorectal cancer refers to cancer that has spread from the colon to distant sites in the body. Chemotherapy remains the mainstay of treatment for patients with advanced colorectal cancer. In addition, targeted therapy, radiation therapy, or surgery may be part of the treatment regimen for advanced colorectal cancer.
FOLFOX is a commonly used chemotherapy regimen consisting of 5-fluorouracil, Eloxatin®, and leucovorin. Xeloda® (capecitabine) is a chemotherapy agent that can be taken orally. It produces the same anticancer effects as 5-fluorouracil.
Researchers continue to evaluate the role of Xeloda given orally (as opposed to intravenous administration, which is required for 5-fluorouracil) in the treatment of various cancers. Administering drugs orally can reduce time and financial burdens along with pain, anxiety, and risk of infection.
Avastin is a targeted agent that belongs to a class of drugs called monoclonal antibodies. Avastin produces its anticancer effects by targeting vascular endothelial growth factor (VEGF) and preventing the interaction of VEGF with its receptors to reduce the growth and spread of cancer cells.
VEGF, a type of protein, is important in a process leading to cellular growth, replication, and spread and to new blood vessel formation. Avastin binds to VEGF and reduces its normal activity. It lessens the growth and spread of cancer cells by inhibiting the growth of new blood vessels, making it harder for the tumor to grow.
Researchers recently conducted a phase III clinical trial comparing FOLFOX to XELOX (Xeloda, Eloxatin, leucovorin) as initial therapy in patients with advanced colorectal cancer. Following chemotherapy, one group of patients was treated with Avastin.
- XELOX was just as effective as FOLFOX in terms of progression-free survival.
- XELOX was more convenient than FOLFOX.
- The addition of Avastin to either chemotherapy regimen significantly improved progression-free survival compared to chemotherapy alone.
- Data for overall survival are not yet mature.
- No new findings regarding side effects were observed in this trial.
The researchers concluded that XELOX is just as effective, though more convenient, than FOLFOX in the treatment of advanced colorectal cancer. Furthermore, the addition of Avastin to either chemotherapy regimen significantly improves progression-free survival compared to chemotherapy only. Follow-up data will report overall survival results.
Reference: Roche. Avastin and Xeloda Set New STandard for the Treatment of First-Line Metastatic Colorectal Cancer. Available at: http://www.roche.com/home/media/med_div/med_div_pharma/med-div-2006-10-02c.htm . Accessed October 2006.