Drug Combination Shrinks Breast Cancer Metastases In Brain

Lapatinib (Tykerb) and capecitabine (Xeloda) were paired in an extension of a Phase 2 clinical trial in which lapatinib given alone shrank brain metastases significantly in six percent of 241 patients.

In the extension trial, capecitabine was added to lapatinib in 49 patients whose metastases -- cancerous colonies in the brain spread from their primary cancer -- had progressed while on treatment. With the combination therapy, brain metastases shrank by 20 percent or more in 18 patients (37 percent) and shrank by at least 50 percent in 10 patients (20 percent), reported Nancy Lin, MD, of Dana-Farber's Breast Oncology Center.

"Very few medications have shown activity in the treatment of brain metastases, particularly in HER-2-positive metastatic breast cancer patients," said Lin, who led the study with Eric Winer, MD, director of the Dana-Farber Breast Oncology Center. "Therefore, these data are quite encouraging, and further studies are warranted."

Lapatinib is an oral small-molecule drug from GlaxoSmithKline that is approved along with capecitabine for treating patients with advanced or metastatic breast cancer whose tumors are driven by the abnormal growth signal, HER-2, and who have already undergone therapy including trastuzumab (Herceptin), a taxane drug, and an anthracycline compound. Lapatinib, like trastuzumab, blocks the HER-2 signal.

Up to one-third of women with advanced, HER-2-positive breast cancer may develop metastases to the brain.

"Although radiation treatment is often effective, as women live longer with metastatic cancer, some develop worsening of brain metastases despite radiation," said Lin. "Because cancer in the brain can have a major impact on quality of life, it is important to have treatment options to address this problem."

The data was presented on Dec. 16, 2007.

The study was sponsored in part by GlaxoSmithKline.