The U.S. Food and Drug Administration (FDA) has approved Phesgo – a combination of pertuzumab, trastuzumab and hyaluronidase – for injection under the skin to treat adult patients with HER2-positive breast cancer that has spread to other parts of the body, and for treatment of adult patients with early HER2-positive breast cancer, according to a press release from the agency.
The FDA said Phesgo is initially used in combination with chemotherapy. However, it could be administered at home by a qualified healthcare professional once the chemotherapy regimen is finished. Patients should be selected based on an FDA-approved companion diagnostic test, the FDA said.
HER2-positive breast cancer, which makes up approximately one-fifth of breast cancers, has too much of a protein called human epidermal growth factor receptor 2 (HER2), which promotes the growth of cancer cells. Pertuzumab and trastuzumab bind to sites on HER2 and disrupt signaling to stop cancer cell growth. Phesgo contains a fixed-dose combination of pertuzumab and trastuzumab with hyaluronidase for injection under the skin. The therapeutic components in Phesgo are the same as those in FDA-approved intravenous (IV) pertuzumab and IV trastuzumab.
The FDA’s approval was based on the results of a non-inferiority study in patients with HER2-positive early breast cancer, which demonstrated Phesgo had comparable efficacy and safety as IV pertuzumab and IV trastuzumab, except for administration-related reactions, which were higher with Phesgo due to the subcutaneous route of administration.
Prescribing information for Phesgo includes a boxed warning to advise healthcare professionals and patients about the risk of potential heart failure, fetal harm, and lung toxicity.
