Home-Based Oral Therapy Produces Responses in Late-Stage Metastatic Breast Cancer

Baylor-Charles A. Sammons Cancer Center and Physician Reliance Network (PRN) Research recently announced data demonstrating that one in five patients with hard-to-treat metastatic breast cancers responded to capecitabine (Xeloda) even though they had previously not responded to treatment with paclitaxel (Taxol) and an anthracycline-containing regimen. Capecitabine is the first chemotherapy for metastatic breast cancer that is biochemically targeted to attack cancer cells.

The data are part of the results of a phase II study of capecitabine that appeared in the February 1999 issue of the Journal of Clinical Oncology. The large, phase II, multicenter trial, conducted at 25 hospitals and cancer centers in the United States and Canada, established that capecitabine is effective even in heavily pretreated patients with metastatic breast cancer. In the study, capecitabine demonstrated a favorable side effect profile.

Therapy Activated by Enzymes Found Primarily in Tumors

“Xeloda is an exciting new option for the treatment of metastatic breast cancer,” said Joanne Blum, MD, PhD, lead investigator of the study. “It is unique among currently available therapies, as it is activated by enzymes in the body that are primarily found in tumors, thus focusing the cancer killing agent primarily at the site of the cancer while limiting adverse events and damage to healthy issue. Xeloda’s pill form permits patients to be treated at home and live more normal lives.”

The clinical trial, involving 163 patients, tested the efficacy and safety of capecitabine at 2,510 mg/m²/d, divided into two daily doses over a period of 2 weeks, followed by a 1-week rest period, and repeated in 3-week cycles. Of the 135 patients with measurable disease, 27 (20%) had complete or partial responses, and 3 achieved a complete remission. The data from this trial were the basis for the approval of capecitabine by FDA in May 1998.

Side Effects Profile

Adverse events associated with the dosing schedule of capecitabine used in this study were predictable and controllable. There were no treatment-related deaths and few treatment-related serious adverse events (12%). Of the 54 serious adverse events, only 18 were considered to be related to the study treatment. The majority of treatment-related adverse events were rated as mild or moderate in intensity (grade 1 or 2) and were generally manageable and reversible after dosage adjustment or drug discontinuation.

Dosage was adjusted at any time during the study on the basis of grade 2 or greater treatment-related adverse events. Treatment was discontinued in only 7% of patients. The most frequent treatment-related adverse events were, in decreasing order of frequency: hand-foot syndrome, diarrhea, nausea, vomiting, and fatigue. Significant hair loss was not reported; rather, hair regrowth occurred in most patients with alopecia at baseline.