FDA Approves Genentech Drug for Breast Cancer

Breast cancer patients won a breakthrough new treatment late Friday as the Food and Drug Administration approved Herceptin--the first in what promises to be a wave of therapies attacking cancer at its genetic roots.

Herceptin is not for every woman with breast cancer. But for the 30% whose especially aggressive tumors are fueled by a bad gene called HER2, Herceptin substantially increases the chances of battling the cancer and living longer.

About 50,000 American women a year could benefit from the drug, manufacturer Genentech Inc. estimates.

“For certain women with advanced disease, this new product can mean new hope,” said Health and Human Services Secretary Donna Shalala.

The FDA approved Herceptin for advanced breast cancer patients whose HER2-positive tumors have spread to other organs, women who until now have had little hope. They can add it to the drug Taxol as first-line therapy or use it alone after failing standard chemotherapies.

To make sure the right patients try Herceptin, the FDA also approved a special genetic test kit, HercepTest by Denmark-based Dako Corp., to help doctors measure levels of the bad gene in breast tumors.

Herceptin is a genetically engineered drug that homes in on the gene fueling growth of aggressive cancer.

“The increased use of biological products such as Herceptin to treat the underlying causes of disease is an exciting development in medicine,” said FDA Acting Commissioner Michael Friedman, who is a cancer specialist.

Shares of South San Francisco-based Genentech rose $1.06 to close at $71.94 on the New York Stock Exchange.

The man whose genetic research led to Herceptin considers it an even bigger development. “It heralds a new age in how we’re going to treat cancer,” said Dr. Dennis Slamon of the Jonsson Cancer Center at UCLA.

Genentech said Herceptin would be on pharmacy shelves next month. Women will get weekly intravenous infusions. A price has not been finalized, Genentech said.

Some 30% of breast cancer patients have too many copies of the HER2 gene. A healthy version of this gene produces a protein that signals cells to grow and multiply normally. But in women who have too much HER2, the breast cells reproduce out of control and spread through the body.

It’s not a magic bullet--it helped only half the women who tested it. But tests in very sick women found that adding Herceptin to standard treatment doubled their chances that tumors would shrink. In women who already had failed standard chemotherapy, Herceptin alone cut in half tumors in 15% of women.

A few of the women went into remission. Most eventually relapsed, but one is alive six years later and another three years later.

The drug improved by 16% the odds of surviving a full year. Most patients, however, saw about three more months before the cancer progressed, a short respite albeit one considered significant in patients this sick.

It did pose one serious danger: It sometimes weakens the heart muscle, which can lead to congestive heart failure.