A new drug has been shown in clinical trials to slow the progression of advanced breast cancer by more than 50 per cent.
Some 13 Irish patients were among 392 women worldwide involved in the trial, which has now been closed down to allow control-group women excluded from the trial to avail of lapatinib, the trade name for which is Tykerb.
Irish patients on the drug are attending hospitals in Dublin, Cork and Galway.
Made by GlaxoSmithKline, the drug is now likely to be tried in women with early-stage breast cancer.
What is regarded in clinical circles as remarkable about the new drug is it worked in patients for whom another relatively new drug, herceptin, failed.
It also comes in tablet form whereas herceptin has to be given intravenously.
The Irish patients got involved in the trial through the Irish Clinical Oncology Research Group. Group chief executive Dr Brian Moulton said the trial had "quite a remarkable result".
He estimated it would be about a year before the drug would be licensed in Ireland. Until then, it will only be available to a limited number of women taking part in clinical trials. "We hope to do our best as an organisation to get it to as many women as possible but we are limited by resources," Dr Moulton said.
Up to 400 Irish women have advanced breast cancer.
Dr John Crown, a consultant oncologist at St Vincent's Hospital in Dublin, and the principal investigator for the research group in the Republic, described the results of the clinical trial as "unbelievably exciting" news.
"Basically this is the latest in what we call molecularly targeted treatments. In the past, most of the drugs we used in treating cancer were non-specific toxins like chemotherapy. However, increasingly we are getting drugs which have been designed to attack specific targets in the cancer cell," Dr Crown said.
"What is really intriguing about this study is that the patients on it had all failed herceptin before, so it's very exciting that we still have another molecular treatment to target these patients." He added that it may be that herceptin and this new drug both have roles at different stages of breast cancer.
The average survival rate for women treated for breast cancer which has spread is two years.