FDA Approves Phesgo for Treatment of Patients With HER2-Positive Breast Cancer Approximately Four Months Ahead of Schedule

The Food and Drug Administration (FDA) on Monday approved Phesgo, a fixed-dose combination of two monoclonal antibodies, that allows the treatment of both early and metastatic HER2-positive breast cancer on an outpatient basis.

The combination includes the targeted drugs Perjeta (pertuzumab) and Herceptin® (trastuzumab) with hyaluronidase (a substance injected into a patient to increase the absorption of medication), and is administered via injection under the skin (subcutaneously) in combination with chemotherapy that is given intravenously. Perjeta and Herceptin inhibit the activity of the protein HER2, which drives this subtype of breast cancer.

“Currently, most patients with HER2-positive breast cancer receive trastuzumab and pertuzumab at infusion centers,” 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, said in a press release issued by the agency. “With a new administration route, Phesgo offers an outpatient option for patients to receive trastuzumab and pertuzumab.”

The agency based its decision on results from a phase 3 trial in which it was shown that Phesgo demonstrated safety and efficacy results similar to those seen with Perjeta and Herceptin delivered intravenously.

The investigators found no new safety issues and noted that the safety profile associated with the subcutaneous injection was comparable to the intravenous administration of Perjeta plus Herceptin and chemotherapy.

Nausea, diarrhea, anemia, lack of energy and hair loss were identified as the most common side effects both treatment arms experienced.

“Phesgo offers a treatment administration that supports the needs and preferences of individual patients and helps to meet the increasing demand across the health care system for faster and more flexible treatment options,” said Dr. Levi Garraway, chief medical officer and head of global product development at Roche, in a company-issued press release.

Phesgo is available in one single-dose vial and can either be administered by a health care professional at a cancer treatment center or at a patient’s home. It is expected that the initial injection will take approximately eight minutes and that each subsequent maintenance dose will take five minutes to inject, according to the company-issued press release. The time it takes to administer these injections is significantly shorter than the IV administration of Perjeta and Herceptin, which usually takes 150 minutes, and also shorter than subsequent maintenance infusions, which take 60 to 150 minutes).

The approval contains a boxed warning alerting health care professionals and patients to the risk of heart failure, harm to a fetus and lung toxicity associated with Phesgo. Additionally, the FDA advises health care professionals to inform female patients of reproductive age that exposure to the treatment during pregnancy or within seven months before conception can result in fetal harm.

“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,” said Pazdur in the agency-issued release. “At this critical time, we continue to expedite oncology product development. This application was approved about four months ahead of the FDA goal date.”