GLASGOW, Scotland"Development of capecitabine (Xeloda) was inspired by the
fact that what is wanted is an oral tablet that will mimic infusional
fluorouracil (5-FU) and will have tumor-selective activation. Clearly, about
90% of patients prefer oral therapy, but they do not want to sacrifice efficacy
for convenience," Christopher Twelves, MD, stated. A number of recent clinical
trials suggest that capecitabine might be a simpler substitute for 5-FU in
colorectal cancer regimens and Dr. Twelves, a consultant in medical oncology at
Cancer Research UK, Glasgow, Scotland, discussed this possibility at the First
International Colorectal Cancer Congress in Palm Beach, Florida.
A phase III study compared single-agent capecitabine to the Mayo Clinic
bolus 5-FU-based regimen in patients with metastatic colorectal cancer.
Capecitabine was given at 1,255 mg/m2 bid for 2 weeks on and 1 week
off. The trial was powered to demonstrate equivalence, meaning that
capecitabine was not any worse than standard therapy. The overall response rate
(complete and partial response) was 26% with capecitabine vs 17% with 5-FU/leucovorin
(P < .0002). "Response was also achieved earlier with capecitabine," Dr.
Toxicity analysis showed that 5-FU/leucovorin caused more stomatitis, and
capecitabine caused more hand-foot syndrome (HFS). However, capecitabine was
associated with a much lower need for hospitalization. The number of
hospitalizations was 40 with capecitabine vs 49 with 5-FU/leucovorin (a
decrease of 18.4%). The number of patients requiring hospitalization was 35/297
with capecitabine vs 47/295 with 5-FU/leucovorin, a decrease of 25.5%.
Capecitabine has been approved for first-line treatment of metastatic
disease. Dr. Twelves said that it has high efficacy, superior response rate,
improved overall survival, is better tolerated than previous regimens, and
yields cost savings.
Combined With Oxaliplatin
Investigators next began to ask whether capecitabine might completely
replace 5-FU in the treatment of colorectal cancer and whether capecitabine
might be combined with oxaliplatin (Eloxatin), because each agent is active in
this setting and there is no overlap in toxicities.
A capecitabine/oxaliplatin combination was tried as first-line treatment for
metastatic colorectal cancer in a nonrandomized multicenter phase II trial of
96 patients. Overall response rate was 55% (95% CI 46%-95%). "There was a
consistent response rate above 50% in all patient subgroups, including those
with prior adjuvant chemotherapy and those with liver or lung metastases," Dr.