An evaluation of the safety and efficacy of capecitabine and paclitaxel as treatment for patients with metastatic breast cancer

This phase III clinical trial examined whether the combination of capecitabine (Xeloda) and paclitaxel (Taxol) is as effective as the combination of epirubicin (Ellence) and paclitaxel (Taxol) as a chemotherapy treatment for patients with metastatic breast cancer (MBC).

One of the current treatment options for patients with MBC (breast cancer that has spread to other parts of the body), is chemotherapy using a combination of drugs, usually an anthracycline/taxane combination. This treatment has been shown to lengthen the time it takes for the disease to progress (progression free survival or PFS). However, this combination may be too toxic for patients who have previously taken anthracyclines (a type of antibiotic used to treat some types of cancer) such as epiruAbicin. The current study examined whether another combination of chemotherapy agents, capecitabine and paclitaxel (together called CP), showes similar benefits as the epirubicin and paclitaxel (EP) combination, more commonly used.

This trial included 340 patients diagnosed with MBC, 59% of which had not previously received any chemotherapy. The patients were divided into two groups: 170 received the EP drug combination and 170 received the CP drug combination. The majority of the patients completed six treatment cycles. The PFS rate was measured for each group.

After approximately 2 years of follow up, CP was found to be as effective as EP, with no significant differences in PFS between the two groups. The PFS for patients who received CP was 10.4 months compared to 9.2 months in patients treated with EP. Both treatment groups responded equally to chemotherapy, with a response rate (percentage of patients who had an improvement of the disease after treatment) of 47% with CP and 42% with EP. Moreover, 28% of patients remained progression-free at the end of the study. Both treatment combinations were well tolerated, the most common side effects being diarrhea and low blood count.

In summary, the combination of the chemotherapy drugs capecitabine and paclitaxel was as effective as the combination of epirubicin and paclitaxel in patients with metastatic breast cancer.

This study was partially funded by both Bristol-Myers Squibb, the manufacturer of Taxol, and F. Hoffman-La Roche, the manufacturer of Xeloda.