May 16 (Reuters) - Treating early stage breast cancer patients for just six months with Roche's Herceptin works as well as the current 12-month regimen, researchers who conducted a large clinical trial said on Wednesday.
Herceptin, a biotech medicine that costs around $76,700 a year in the United States, generated 2017 worldwide sales of more than $7 billion for Roche. If a shorter treatment duration is widely adopted it could significantly reduce sales.
Halving treatment duration reduces the number of people who have to quit therapy due to side effects and "obviously will have an effect on cost as well," Dr. Bruce Johnson, president of the American Society of Clinical Oncology (ASCO), said during a conference call with reporters. He added that patients in the study need to be followed to see how they fare longer term.
Roche, in an emailed statement, said other studies have not shown that a shorter treatment duration works as well as 12 months, and emphasized that use of Herceptin for one year is the only FDA-approved indication for HER2-positive early breast cancer.
The Herceptin trial is one of thousands of cancer drug studies set to be presented at ASCO's annual meeting next month in Chicago. Brief summaries of many of them were released on Wednesday.
Herceptin, first approved in 2005, is used for cancer patients whose tumors generate a protein called HER2, which accounts for about 25 percent of breast cancer cases. About 15 percent are early-stage HER2 disease. The injected drug, known chemically as trastuzumab, can cause serious side effects, including heart failure.
The 4,089-patient study, funded by Britain's National Institute for Health Research, found that after surgery 89.4 percent of patients given six months of Herceptin were alive with no signs of cancer four years later, compared with 89.8 percent of women treated for 12 months.
In addition, four percent of women in the six-month group stopped treatment because of heart problems, compared with eight percent in the 12-month group.
"We are confident that this will mark the first steps towards a reduction in treatment duration for many women with HER2-positive breast cancer," said Dr. Helena Earl, the study's lead investigator and professor of clinical cancer medicine at the University of Cambridge.
Research is continuing to determine the impact of treatment length on quality of life as well as to define which patients are best suited for less treatment, Dr. Earl said.
Dr. Richard Schilsky, ASCO's chief medical officer, said the study follow-up is still relatively short, but the results "likely will signal a shift, even in the U.S. oncology community, toward shorter duration of trastuzumab (post surgery)therapy." (Reporting By Deena Beasley Editing by Bill Berkrot)