The drug could also remove the need for radical chemotherapy.

Dr. David Miles, a cancer specialist hospital at Mount Vernon Hospital, Middlesex, who is one of the study authors says the use of the combination therapy in one quarter of the women, shrunk their tumours and in another quarter, stabilised their growth.

Dr. Miles says the study results are impressive considering that this was a treatment regimen containing two antibodies only and did not involve any chemotherapy.

He says the drug has the potential to target and block a highly relevant pathway for tumour growth and the combination of trastuzumab and pertuzumab used with chemotherapy will be even more effective if used to treat women newly diagnosed with advanced cancer.

The clinical trial results were presented at the American Society of Clinical Oncology conference in Chicago last week.