LISBON, PortugalThe combination of capecitabine(Drug information on capecitabine) (Xeloda) and oxaliplatin(Drug information on oxaliplatin) (investigational in the United States) produced a 55% response rate in a phase II study of patients with advanced or metastatic colorectal cancer, Chris Twelves, MD, of Beatson Oncology Centre, Glasgow, Scotland, said at the 11th European Cancer Conference (abstract 1005). In addition, he said, 32% of patients in the study had stable disease.
Capecitabine is a novel oral fluoropyrimidine that is converted to fluorouracil(Drug information on fluorouracil) (5-FU) at the tumor site by exploiting the higher activity of thymidine phosphorylase in malignant tissue, Dr. Twelves said. "It has demonstrated superior activity and an improved safety profile, compared with IV bolus 5-FU/leucovorin (Mayo Clinic regimen) in two large phase III trials," he said.
The current open-label, single-arm study enrolled 96 patients at 13 centers in eight countries. Patients received oral capecitabine, 1,000 mg/m² taken at home twice daily on days 1 to 14 of a 3-week cycle, and a 2-hour infusion of oxaliplatin, 130 mg/m² on day 1.
Dr. Twelves emphasized that patients on this regimen spend only a few hours in the clinic each month. In contrast, 5-FU/leucovorin is given as a continuous infusion for 48 hours every 2 weeks.
He pointed out that the 55% response rate was consistent across all subgroups, including patients with liver and lung metastases, patients who had received primary adjuvant chemotherapy, and patients with lower performance status. The average duration of response, he said, is currently 8 months, and the median time to progression is 7.1 months. Median survival, he noted, had not been reached 15 months after the start of the trial and 7 months after enrollment of the last patient.