An international trial of a new breast cancer drug has shown the drug is able to shrink tumours caused by one of the most aggressive forms of the disease.
The new drug pertuzumab was given to women with with an advanced and aggressive HER2-positive form of breast cancer.
The drug trastuzumab (Herceptin) had already been tried with the women without success but when they were treated with a combination of Herceptin and Pertuzumab, some of the growths began to reduce in size.
The trial involved 66 women from the UK, France, Italy, Spain and Canada who had advanced breast cancer which had already spread to other organs.
The Phase II trial revealed that one in four given the drug saw a reduction in the size of their tumours and another one in four found that their tumours had not grown larger.
The success of the combo of trastuzumab and pertuzumab offers new hope to the thousands of women diagnosed each year with aggressive HER2-positive breast cancer.
HER2-positive breast cancer accounts for 20 to 30 per cent of all breast cancer cases and is harder to treat as it does not respond well to chemotherapy.
HER2-positive breast cancer means a protein known as HER2 is found on the surface of the tumour cells and pertuzumab works by preventing the HER2 protein from binding with other cells, which is thought to encourage the growth and spread of the cancer.
This is the first time a drug has been found which acts in this manner.
Experts are optimistic that hope they will eventually prevent breast cancer from initially forming by giving the drug to high-risk women who test positive for the HER2 protein.