Xeloda is not a cure, the FDA warned Thursday. Nor is there yet proof that the pills extend these women's lives.
Early studies suggest, however, that Xeloda can shrink tumors significantly in one out of four patients with advanced breast cancer - data promising enough that the FDA approved the pill for sale under a special program that allows certain medicines to be sold before scientists finish proving their effectiveness.
And Xeloda appears to have fewer side effects than typical chemotherapy.
"This is the beauty of this drug: I have my hair, I'm not nauseous, I'm not wearing a pump," said Cathy Adelson, 53, of Houston, who joined a clinical trial of Xeloda in October 1996 after failing every conventional treatment, and almost immediately saw her condition improve.
Adelson had been taking a powerful prescription painkiller for severe cancer pain but said she didn't need even an aspirin after six weeks of Xeloda. The breast cancer that had spread to her bones is still there but does not appear to be growing, and two cancerous lesions on her liver disappeared five months into therapy.
"I really am exceedingly grateful for the 18 months Xeloda has given me, and hope I'll have a bunch more," said Adelson, who says she's now active enough to care for her young grandchildren.
An estimated 44,000 women will die this year of advanced breast cancer that has spread to other parts of the body.
Once that happens, the state-of-the-art treatment is Taxol taken with a class of potent chemotherapy drugs called anthracyclines. These drugs can cause powerful side effects, not just the hair loss and nausea normally associated with chemotherapy but even deadly heart poisoning.
When these drugs fail, or when women's bodies simply cannot tolerate taking anthracyclines, doctors are at a loss about what to offer next.
The other promising option is continual infusion of a drug called 5FU. Women wear a supply of the drug in a shoulder pack with a line that pumps it straight into a catheter near the neck 24 hours a day. About 20 percent of women are expected to respond.
But that treatment is so arduous that few doctors prescribe it, and few women can tolerate it for long.
Hoffman-La Roche's Xeloda offers the advantage of this constant infusion in a simple prescription pill.
Known chemically as capecitabine, Xeloda is converted into 5FU by an enzyme found predominantly in tumors. Thus, swallowing the pill is easier than wearing a pump.
Xeloda will reach pharmacies in May and will be marketed at a price still to be set.
In a study of 135 patients with advanced breast cancer, tumors shrank by at least half in 18.5 percent of the women, the FDA sai. More importantly, in 43 patients who failed both Taxol and anthracyclines, Xeloda helped shrink tumors in 25 percent of patients.
Although the shrinkage numbers sound small, they were significant for such an aggressive disease, and most women's cancer did stabilize, said Dr. Linda Vahdat of Columbia-Presbyterian Medical Center, who participated in the trial.
"What's particularly gratifying about it is they had virtually no side effects," she added.
The most common side effects were diarrhea and "hand-foot syndrome," in which patients' extremities become irritated, numb and occasionally suffer more extensive nerve damage. Side effects, however, generally abated when doses were decreased.
Written by Lauran Neergaard