The US Food and Drug Administration (FDA) has granted a Biologics License Application (BLA) to the HER2 dimerisation inhibitor pertuzumab developed by Roche (Basel) for previously untreated HER2-positive metastatic breast cancer. The humanised monoclonal antibody is to be used in combination with Herceptin (trastuzumab) and docetaxel chemotherapies. The FDA approval is based on results from the pivotal Phase III Cleopatra study, which demonstrated a 6.1 month improvement in median progression-free survival. People who received the combination also experienced a 38% reduction in the risk of their disease worsening or death, according to Roche. The mechanisms of action of pertuzumab and Herceptin are believed to complement one another, as both bind to the HER2 receptor, but to different regions.