Pharmacist Medication Insights: Phesgo for HER2-Positive Breast Cancer

The combination of pertuzumab, trastuzumab and hyaluronidase–zzxf is indicated for adult patients with HER2-positive breast cancer that has spread to other parts of the body and for adult patients with early HER2-positive breast cancer.

In June 2020, theFDA approved Phesgo, which is a combination of pertuzumab, trastuzumab and hyaluronidase–zzxf. The therapy is injected subcutaneously for the treatment of adult patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer that has spread to other parts of the body, and for adult patients with early HER2-positive breast cancer.

HER2-positive breast cancer, which comprises approximately one-fifth of breast cancers, has an excess of the HER2 protein, which promotes the growth of cancer cells. Pertuzumab and trastuzumab bind to sites on HER2 and disrupt signaling to inhibit cancer cell growth. Phesgo is initially used in combination with chemotherapy and could continue to be administered at home by a qualified health care professional once the chemotherapy regimen is finished, according to the FDA.