Infusional 5-FU or oral Xeloda® (capecitabine) are two different drugs that can be combined with Eloxatin® (oxaliplatin) to treat colorectal cancer that has spread. Six different randomized clinical trials have compared the two approaches.
Researchers analyzed a pool of all six trials to find out if one approach is better than the other. While they found that there are different side effects, the time until cancer gets worse (progression-free survival) and overall survival time are the same.
The percentage of patients who got infusional 5-FU and had their tumors shrink (response rate) was greater than those who had shrinkage with capecitabine . However, this did not translate into better progression-free interval or longer survival time.
Six randomized phase II or III studies compared CAPOX to some infusion 5-FU regimen combined with oxaliplatin. Nearly 3,500 people took part in the clinical trials. Two trials also included Avastin® (bevacizumab).
While there was a 15 percent better response rate with infusion 5-FU, there was no difference in either progression-free interval or overall survival time.
Patients who received Xeloda had more blood clots, serious diarrhea, and changes in the skin on their hands and feet (hand-foot syndrome). 5-FU treatment caused more low white cells counts (neutropenia).
In discussing side effects, the researchers noted that lower doses of Xeloda might have reduced its side effects and that lower doses are being used in some new studies of the drug.
Writing in the Journal of Clinical Oncology, Hendrik-Tobias Arkenau and a collaborating team of international researchers said,
The combination of capecitabine and oxaliplatin resulted in lower response rate, but this did not affect progression-free survival and overall survival, which were similar in both treatment arms. The toxicity analysis showed the characteristic toxicity of each of the different FU schedules, with thrombocytopenia and hand-foor syndrome consistently more prominent in the capecitabine regimens.
Further, they wrote,
Thus, the use of capecitabine and oxaliplatin is a valid alternative for patients with metastatic colorectal cancer and can be regarded as appropriate backbone for the addition of novel targeted agents in clinical practice and future clinical trials.
SOURCE: Arkenau et al., Journal of Clinical Oncology, published ahead of print, November 17, 2008.