Phesgo® (pertuzumab, trastuzumab, and hyaluronidase-zzxf) is a prescription medicine approved for use in combination with chemotherapy to treat certain kinds of early and metastatic HER2-positive breast cancer. It is designed to target HER2 receptors, disrupting cancer cell growth and interfering with HER2 signaling to help slow or stop tumor progression.
Phesgo is administered as an injection under the skin. The initial dose is a single 15 mL injection administered subcutaneously over approximately 8 minutes. This is followed by maintenance doses administered subcutaneously over approximately 5 minutes every 3 weeks. Your healthcare provider will determine the appropriate dosing schedule based on your specific medical condition and treatment progress.
Serious side effects of Phesgo include heart problems, death of an unborn baby, birth defects, and serious lung problems. Phesgo should not be used in patients who are allergic to Phesgo or to any of the ingredients in Phesgo. Other possible serious and sometimes fatal side effects include worsening of low white blood cell counts caused by chemotherapy and severe allergic reactions. The most common side effects of Phesgo when given with chemotherapy include hair loss, nausea, diarrhea, low levels of red and white blood cells, weakness or feeling tired, rash, and damage to the nerves.