Pertuzumab (also called 2C4, trade name Perjeta) is a monoclonal antibody marketed by Genentech for the treatment of HER2-positive breast cancer, in combination with trastuzumab and docetaxel. The first of its class in a line of agents called "HER dimerization inhibitors". By binding to HER2, it inhibits the dimerization of HER2 with other HER receptors, which is hypothesized to result in slowed tumor growth. Pertuzumab received US FDA approval for the treatment of HER2-positive metastatic breast cancer on June 8, 2012. Pertuzumab was developed at Genentech and is now owned by Roche which acquired Genentech in 2009.