Glaxo breast cancer pill wins FDA approval

WASHINGTON (Reuters) - GlaxoSmithKline Plc won U.S. approval for a once-a-day breast cancer pill on Tuesday that the drugmaker hopes will launch a new era for its oncology business.

The Food and Drug Administration cleared the drug, called Tykerb, for patients with advanced breast cancer in combination with Roche Holding AG's oral chemotherapy drug, Xeloda, or capecitabine.

It is the first of four cancer drugs that Glaxo hopes to have approved by 2010. Studies of Tykerb, or lapatinib, to treat early-stage and inflammatory breast cancers, as well as head/neck, gastric and lung cancers, are also underway.

For now, the FDA approved Tykerb for patients with HER-2 positive breast cancer who no longer respond to Roche and Genentech Inc.'s rival product, Herceptin.

Patients should have also tried anthracycline and taxane chemotherapy drugs such as Sanofi-Aventis's, Taxotere, or Bristol-Myers Squibb's, Taxol.

"New targeted therapies such as Tykerb are helping expand options for patients," said Dr. Steven Galson, head of the FDA's Center for Drug Evaluation and Research.

Side effects can include diarrhea, nausea and rash, as well as numbness and other discomfort in the hands and feet.

Overall, nearly 182,000 women were diagnosed with breast cancer and another nearly 42,000 died from it in 2003, based on the most recent data available from the U.S. Centers for Disease Control and Prevention. Men are also at risk.

About 8,000 to 10,000 women die each year from HER-2 positive breast cancer, a more aggressive disease in which the human epidermal growth factor receptor 2 is over-expressed, according to the FDA.

Some analysts expect Tykerb to reach annual sales of about $1.35 billion by 2010. With wider approval, that could jump as high as $4 billion a year, they say.

Glaxo shares recovered earlier losses after the news to close down 75 cents at $55.25 on the New York Stock Exchange.

'DIFFERENT WEAPONS'

Dr. Howard Burris, head of drug development at the Sarah Cannon Research Institute, said Glaxo's pill is another tool as current therapies see less success.

"More and more women take Herceptin for a period of two to five years and then become resistant to it. The cancer cells mutate and figure out a different way to get around the antibody," said Burris, who led some of Glaxo's trials.

Glaxo's oncology head, Paolo Paoletti, said the drug's novel mechanism of action was key.

Unlike Herceptin, which aims to block cancer from outside the cell, Tykerb works within cells by blocking two enzymes thought to promote cancer called kinases.

"You need to fight cancers using different weapons. The antibody is one weapon and the kinase inhibitor is another weapon," he told Reuters.

But Dr. Pam Klein, Genentech's vice president of clinical oncology and hematology, said physicians would have to carefully weigh any switch.

"Until we've had a bit more data with Tykerb, it is difficult to know how Tykerb will react under those same circumstances," she said.

Physicians expect patients to welcome the convenience of a daily pill that frees them from frequent office visits for infused therapies.

But it is not clear how insurers will cover the drug's $2,900 monthly cost, especially for older patients in the nation's Medicare program. Infused cancer drugs are covered under Medicare, but not pills, which fall under the program's voluntary prescription drug coverage plans.

A Glaxo spokeswoman said it will give Tykerb free to patients with incomes at or below 500 percent of the poverty level, or about $68,450 for a family of two.

(Additional reporting by Ben Hirschler in London)