A trial looking at trastuzumab and capecitabine with or without pertuzumab for advanced HER2 positive breast cancer - PHEREXA

This trial is looking at adding a new drug called pertuzumab to trastuzumab (Herceptin) and capecitabine for women with breast cancer that has spread (secondary breast cancer). It is for women whose breast cancer is HER2 positive. This means the breast cancer cells have tested positive for a protein called HER2.

Doctors often treat HER2 positive breast cancer with trastuzumab. This is a type of biological therapy called a monoclonal antibody. It works by targeting and blocking the HER2 protein on the cancer cell.

Pertuzumab is a monoclonal antibody which also targets HER2 and works with trastuzumab in a complementary way.

We know from research that giving both these drugs together to women with HER2 positive breast cancer may be better than just giving one.

We also know from research that combining capecitabine with trastuzumab is better than capecitabine alone for women with HER2 positive breast cancer.

The aim of this trial is to find out if giving pertuzumab with trastuzumab and capecitabine is better than trastuzumab and capecitabine for women with HER2 positive breast cancer. And to find out more about the side effects of this combination of treatments.