ORLANDO—Adding capecitabine(Drug information on capecitabine) (Xeloda) to docetaxel(Drug information on docetaxel) (Taxotere) (XT) significantly improves response rates, time to progression, and overall survival, compared with docetaxel alone in patients with metastatic breast cancer, according to results of a phase III study of the combination.
Lead investigator Joyce O’Shaughnessy, MD, co-director of breast cancer research at Baylor-Sammons Cancer Center and US Oncology, Dallas, updated the results of the trial at an industry-sponsored symposium held in conjunction with the 38th Annual Meeting of the American Society of Clinical Oncology. The study findings were recently published in the Journal of Clinical Oncology (20:2812-2823, 2002).
"The capecitabine/docetaxel combination is the first cytotoxic combination that has been shown to have a survival advantage over single-agent docetaxel," Dr. O’Shaughnessy commented. "Both drugs are very active single agents, and I would argue that they are two of the very few cytotoxic agents we have that can impact the natural history of metastatic breast cancer."
Distinct Mechanisms
Dr. O’Shaughnessy noted that the two agents have distinct mechanisms of action and limited overlap of toxicities. Moreover, taxanes further upregulate thymidine phosphorylase—and thus promote the tumor-selective accumulation of fluorouracil(Drug information on fluorouracil) (5-FU)—and capecitabine/taxane combinations have shown clear synergistic activity in preclinical studies.
Study Protocol
In the phase III trial of the capecitabine/docetaxel combination, 511 anthracycline-pretreated women with measurable metastatic breast cancer were randomized to receive either full-dose docetaxel (100 mg/m² on day 1) or 75 mg/m² of docetaxel on day 1 and full-dose capecitabine (1,250 mg/m² bid on days 1 to 14, with 7 days off).
