WEDNESDAY, May 19, 2004 (HealthDayNews) -- The chemotherapy drug Herceptin, once associated with severe cardiac side effects, is safe and effective for treating advanced breast cancer when combined with the right drugs, researchers report.
In two studies in the May 19 issue of the Journal of the National Cancer Institute, researchers have shown, both in experiments with cancer cells and in cancer patients, that Herceptin (trastuzumab) in combination with other chemotherapy drugs effectively fight cancer without side effects.
"We found that a combination of the chemotherapy drugs docetaxel, cisplatin or carboplatin, and Herceptin were effective in treating patients with HER2-positive advanced breast cancer," said lead author Dr. Mark D. Pegram, an associate professor of hematology and oncology from the UCLA School of Medicine.
Human epidermal growth factor receptor 2 (HER2) is present in the tumors of 20 percent to 30 percent of breast cancer patients. And it is associated with an increased risk of relapse and death in patients with early-stage breast cancer.
In previous clinical trials, Herceptin, which blocks HER2, increased response rate and survival, but many patients developed cardiac dysfunctions, including heart failure.
To see if Herceptin could be used safely, Pegram's team, using cancer cells, tested various combinations of Herceptin and other chemotherapy drugs to see which mixtures were the most effective and safe.
The most effective and safest combination was found in a synergistic interaction of Herceptin plus carboplatin and docetaxel, Pegram said.
In the next phase of their research, the investigators used this combination of drugs to treat two groups of women with advanced breast cancer.
In these two phase II trials, one group was given docetaxel and Herceptin with cisplatin. The other group was treated with docetaxel and Herceptin and carboplatin.
"These combinations had the same toxicity as using docetaxel plus cisplatin or carboplatin without Herceptin," Pegram said, and there were very few cases of cardiac problems.
"Moreover, the overall response rates were higher with Herceptin than with the other drugs alone," Pegram added.
Pegram believes these trials will show these new synergistic chemotherapy combinations will be both safe and effective for women with breast cancer.
"These are informative studies, the results of which have been widely known for several years in the oncology community," said Dr. Harold J. Burstein, from the Breast Oncology Center at the Dana-Farber Cancer Institute and an assistant professor of medicine at Harvard Medical School.
Burstein went on to note that others have had similar results using Herceptin and chemotherapy combinations, but not to treat breast cancer.
"These trials have had clinical impact, and these chemotherapy combinations have become very widely used regimens," he said. "The story is that laboratory science redirected clinical medicine onto a more productive avenue.
"In the era of targeted therapy, we can use these laboratory data to suggest further specific combinations of novel drugs and old drugs, which might be different combinations than we usually grab off the shelf," Burstein said.