In The News

That is revolutionary
Herceptin targets cancerous cells, halves relapse rates for patients with certain tumors but presents side effects.

By GENE EMERY
Reuters
October 20, 2005

MAKING PROGRESS: While the news about Herceptin’s success is welcomed, doctors also are warning that it doesn’t work on all types of breast cancers and isn’t for everyone.   BUSINESS WIRE

BOSTON - In studies described as "stunning," researchers reported Wednesday that a drug already used to treat advanced cancer can prevent half of certain breast tumors from reappearing after standard therapy.

But the treatment only works in women whose breast tumors carry excessive amounts of a protein known as HER2 that makes the cancer particularly aggressive, and on occasion may cause serious side effects.

About one in five women with breast cancer have such tumors, so 42,000 U.S. women could benefit from the treatment.

The drug is trastuzumab, sold under the brand name Herceptin by Genentech Inc. in the United States and by Swiss drug maker Roche in Europe.

"Herceptin only goes to the HER2 protein. It doesn't hurt your good healthy cells on its way there, and that is revolutionary," said Sandy Finestone, coordinator of cancer patient services at Hoag Memorial Hospital Presbyterian in Newport Beach. "The problem is that women are going to think it's for everyone that's diagnosed, and it's not."

Approved in 1998 to treat breast tumors that have spread, routine use of Herceptin cuts the recurrence rate by nearly 50 percent, at least over the short term, two new studies in The New England Journal of Medicine show.

"This is a very important finding. It's likely to change the recommended care for patients. But we need to know more about the side effects and the long-term effectiveness," said Richard Gelber of the Dana-Farber Cancer Institute and an author of one study known as the HERA study.

"The results are simply stunning," said Gabriel Hortobagyi of the University of Texas M.D. Anderson Cancer Center in Houston, who predicted in a Journal editorial that the findings "will completely alter our approach to the treatment of breast cancer."

But there are potentially troubling side effects.

Trastuzumab can damage the heart in some women, although the problems usually fade if the drug is discontinued, Gelber said. In addition, women who receive the drug after breast cancer surgery are more likely to develop subsequent tumors in the brain or elsewhere in the nervous system.

But in an era when doctors are happy if a drug improves the survival rate by just a few percentage points, a medicine that cuts the tumor recurrence rate by nearly 50 percent is considered a significant improvement.

Only tamoxifen, a mainstay of cancer treatment, produces such good results, said Hortobagyi. HER2 tumors tend to be resistant to tamoxifen, said Harold Burstein of Dana-Farber.

Tamoxifen and Herceptin are considered targeted therapies because they attack specific cancer cell types. The drugs allow doctors to be more selective in their treatment depending on a patient's type of cancer.

"In the future, we're going to be using more targeted therapies and less chemotherapy, which is a general cell killer," said Dr. Lisa Curcio, medical director of Advanced Breast Care Specialists of Orange County.

As doctors continue to learn about the molecular basis of cancers, treatments will become even more specific, Curcio said.

"All of this recent data has really changed the way a lot of people are getting treated," Curcio said. Researchers must still determine if trastuzumab would work even better if given in chemotherapy or for more than a year.

In the HERA study, sponsored by Roche, 3,387 women in 39 countries were given standard surgery and chemotherapy but half received trastuzumab every three weeks for a year.

A year after treatment ended, doctors found only 127 instances of death, new cases of breast cancer or some other type of tumor among the trastuzumab recipients compared to 220 such cases among volunteers who did not get the drug.

Results of these ground-breaking studies were released and well-publicized in late April, when researchers disclosed their preliminary data at a meeting of the American Society of Clinical Oncology medical conference. But now that the findings are being released in the New England Journal of Medicine, with an editorial calling the results “simply stunning,” the buzz is on.

About six percent of the patients stopped taking the drug because of adverse results. The risk of heart problems was low, the study said, "but this could change with longer follow-up."

Results of the second study, a combination of two studies partly funded by Genentech, were released in April by the National Institutes of Health.

They found a similar reduction in death or new cancer among women who got trastuzumab with conventional chemotherapy.

But the rate of heart problems was much higher - 4.1 percent against less than 1 percent in the HERA study.
 

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