FDA approves new administration route for Phesgo to treat breast cancer

The US Food and Drug Administration (FDA) has approved Phesgo (a combination of pertuzumab, trastuzumab and hyaluronidase–zzxf) 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.

The FDA says that the drug can now be administered at home by a healthcare professional. The approval of Phesgo has been granted to Genentech Inc.

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.

“Currently, most patients with HER2-positive breast cancer receive trastuzumab and pertuzumab at infusion centres. With a new administration route, Phesgo offers an out-patient option for patients to receive trastuzumab and pertuzumab,” said Dr Richard Pazdur, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Oncologic Diseases in the FDA’s Center for Drug Evaluation and Research. “As part of the FDA’s ongoing commitment to address the novel coronavirus pandemic, we continue to keep a strong focus on patients with cancer who constitute a vulnerable population at risk of contracting the disease. At this critical time, we continue to expedite oncology product development. This application was approved about four months ahead of the FDA goal date.”

HER2-positive breast cancer 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 signalling to stop 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.

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.