Many women with a common and aggressive form of breast cancer that is treated with Herceptin can get by with six months of the drug instead of the usual 12, greatly reducing the risk of heart damage it sometimes can cause, a study suggests.
It's good news, but it comes nearly two decades after the drug first went on the market, and many patients have suffered that side effect.
The study was done in the United Kingdom and funded by U.K. government grants. Results were released by the American Society of Clinical Oncology and will be presented at the group's meeting next month.
Herceptin transformed the care of a dreaded disease when it was approved in 1998 for women with advanced breast cancers whose growth is aided by a faulty HER2 gene, as 15 percent to 20 percent of cases are. It was later approved for treatment of those cancers in earlier stages, too, based on studies that had tested it in patients for 12 months. That guess, that the drug should be taken for a year, became the standard of care.
But the drug can hurt the heart's ability to pump. That often eases if treatment is stopped, but the damage can be permanent and lead to heart failure.
"There's no reason to not immediately change practice. The findings are persuasive," said Richard Schilsky, M.D., chief medical officer for the oncology society. Most of Herceptin's cancer-fighting benefit seems to come in the early months of use, he said.