Definition

A combination of three drugs used with other drugs to treat adults with HER2-positive breast cancer. It is used before surgery in patients with locally advanced, inflammatory, or early-stage breast cancer and after surgery in patients with early-stage breast cancer who have a high risk that their cancer will recur (come back). It is also used to treat patients with breast cancer that has spread to other parts of the body and has not already been treated with anti-HER2 therapy or chemotherapy. Pertuzumab and trastuzumab bind to a protein called HER2, which is found on some breast cancer cells. Pertuzumab and trastuzumab may block HER2 and help the immune system kill cancer cells. Hyaluronidase allows pertuzumab and trastuzumab to be given by injection under the skin. Pertuzumab, trastuzumab, and hyaluronidase can be given in less time than pertuzumab or trastuzumab alone, which are given as infusions. Also called Phesgo.