Pertuzumab
Say it: per-TOO-zoo-mab · Brand names: Perjeta, Phesgo
Pertuzumab is a targeted antibody medicine that blocks a protein called HER2 that helps some breast cancers grow.
What it is
Pertuzumab sticks to HER2 in a different spot than trastuzumab. Used together, the two medicines block HER2 growth signals more fully. It is almost always given with trastuzumab and often with chemotherapy.
Often used for
- HER2 positive breast cancer before surgery
- HER2 positive breast cancer after surgery when the risk of return is high
- HER2 positive breast cancer that has spread
How you get it
Pertuzumab is usually given as an infusion into a vein once every 3 weeks. The first infusion takes about 60 minutes, and later ones take 30 to 60 minutes. One product (Phesgo) combines pertuzumab and trastuzumab in a single shot under the skin that takes a few minutes. Your schedule may be different.
Common side effects and what helps
- Diarrhea. Drink plenty of fluids and ask your team what medicine to use.
- Hair loss, mostly from the chemotherapy given with it. A soft hat or scarf can help.
- Nausea. Eat small, bland meals.
- Feeling tired. Rest and short walks can help.
- Rash. Use gentle soap and unscented lotion.
- Low white blood cells, which raises the risk of infection. Wash your hands often.
- Numbness or tingling in your hands or feet, mostly from the chemotherapy. Tell your team if it gets worse.
Call your care team right away if you have
- Shortness of breath, swelling in your legs, fast weight gain, or a racing heartbeat
- Diarrhea that does not stop or makes you feel dizzy or dry
- A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher
- Trouble breathing, chills, or swelling of the face during or after the infusion
Before you start, tell your team
- If you have heart problems
- If you have had chemotherapy medicines like doxorubicin before
- If you are pregnant, may become pregnant, or are breastfeeding
- All the medicines, vitamins, and herbal products you take
Good to know
- This medicine can weaken the heart. You will have heart tests before and during treatment.
- This medicine can harm an unborn baby. Use birth control during treatment and for 7 months after the last dose. If you become pregnant, tell your team right away.
- Infusion and allergic reactions can happen. Your team will watch you during and after each dose.
Questions to ask
- Will I get the infusion or the shot under the skin?
- How often will you check my heart?
- How long will I get this medicine?
- What should I do if I get diarrhea?
Part of these treatment plans
Side effect guides
- Fatigue (tiredness)
- Nausea and vomiting
- Diarrhea
- Hair loss
- Low white blood cells and infection risk
- Neuropathy (numbness and tingling)
- Skin rash (including EGFR-inhibitor rash)
Sources
Quick answers
- What is Pertuzumab?
- Pertuzumab is a targeted antibody medicine that blocks a protein called HER2 that helps some breast cancers grow. Brand names: Perjeta, Phesgo.
- What is Pertuzumab used for?
- HER2 positive breast cancer before surgery; HER2 positive breast cancer after surgery when the risk of return is high; HER2 positive breast cancer that has spread.
- How is Pertuzumab given?
- Pertuzumab is usually given as an infusion into a vein once every 3 weeks. The first infusion takes about 60 minutes, and later ones take 30 to 60 minutes. One product (Phesgo) combines pertuzumab and trastuzumab in a single shot under the skin that takes a few minutes. Your schedule may be different.
- What are the common side effects of Pertuzumab?
- Diarrhea. Hair loss, mostly from the chemotherapy given with it. Nausea. Feeling tired. Rash. Low white blood cells, which raises the risk of infection. Numbness or tingling in your hands or feet, mostly from the chemotherapy.
- When should I call my care team while taking Pertuzumab?
- Shortness of breath, swelling in your legs, fast weight gain, or a racing heartbeat; Diarrhea that does not stop or makes you feel dizzy or dry; A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher; Trouble breathing, chills, or swelling of the face during or after the infusion.
- Which chemotherapy plans include Pertuzumab?
- TCHP, THP.
Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.