Pertuzumab

Pertuzumab is a humanized monoclonal antibody that targets the human epidermal growth factor receptor 2 (HER2). It binds to subdomain II of HER2 and prevents receptor dimerization with other members of the HER family, especially HER3, thereby inhibiting downstream signaling through pathways such as PI3K/AKT and MAPK. This mechanism complements other anti-HER2 therapies by blocking additional aspects of HER2-driven growth and facilitating antibody-dependent cellular cytotoxicity.

Clinically, pertuzumab is used in combination regimens for HER2-positive cancers. In the United States, it is approved for use with trastuzumab and a taxane as initial therapy for metastatic HER2-positive breast cancer and for neoadjuvant treatment of HER2-positive breast cancer to increase pathological complete response rates. It is also approved in several regions for first-line treatment of HER2-positive metastatic gastric or gastroesophageal junction cancer in combination with trastuzumab and chemotherapy, based on studies showing an overall survival benefit when added to standard therapy.

Administration and safety considerations include intravenous infusion, typically given every three weeks in combination regimens. Cardiac monitoring, including periodic assessment of left ventricular ejection fraction, is recommended due to the risk of cardiotoxicity. Common adverse effects can include diarrhea, alopecia, nausea, fatigue, and infusion-related reactions. Pertuzumab is marketed under the brand name Perjeta and was developed by Genentech, a subsidiary of Roche.