Generic Name: Pertuzumab/trastuzumab/hyaluronidase

Pronunciation: N/A

Abbreviation: N/A

Other Market Name: N/A

Drug Class: Targeted Therapy Medications

Company: Genentech

Approval Status: Approved

Generic Version Available: No

Experimental Code: N/A

Drug Indication

Phesgo is an injectable fixed-dose combination regimen containing pertuzumab, trastuzumab and hyaluronidase that can be administered by a health care provider at home. It is approved for people with early or metastatic HER2-positive breast cancer.

General Info

About 20% of breast cancers have a high level of human epidermal growth factor receptor 2 (HER2), which plays a role in cell division and repair. Phesgo contains two HER2 inhibitors, pertuzumab (marketed alone as Perjeta) and trastuzumab (Herceptin and biosimilars).

Phesgo is used with chemotherapy as neoadjuvant (presurgery) treatment for early breast cancer, as adjuvant (follow-up) treatment for early breast cancer with a high risk of recurrence or as treatment for metastatic breast cancer that has not previously been treated with chemo or HER2 inhibitors. A study showed that Phesgo injections are as effective as IV infusions of pertuzumab and trastuzumab. Phesgo was first approved in June 2020.


Dosing Info:

Phesgo is administered as an injection under the skin of the thigh, usually every three weeks, in conjunction with IV chemotherapy.

Side Effects

Common adverse reactions (some of which may be due to accompanying chemotherapy) include hair loss, nausea, diarrhea, rash and peripheral neuropathy. The combination can cause depletion of red blood cells (anemia) and white blood cells (neutropenia), which can lead to fatigue and infections. Potential serious side effects may include heart problems, lung problems, infusion reactions and severe allergic reactions. Phesgo can cause fetal harm if used during pregnancy.

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Last Reviewed: August 9, 2020