Perjeta (pertuzumab) is a targeted biologic medicine used to treat HER2-positive breast cancer. It is a monoclonal antibody that targets the HER2 protein, which drives cancer growth in HER2-positive tumours.

Perjeta and trastuzumab (Herceptin) both target HER2 but at different binding sites. When used together (dual HER2 blockade), they are more effective than either alone. Perjeta is therefore almost always given in combination with trastuzumab (and a taxane chemotherapy) rather than on its own.

It is used:

• As neoadjuvant treatment (before surgery) in HER2-positive early breast cancer
• As adjuvant treatment (after surgery) in HER2-positive early breast cancer with residual disease or high-risk features
• For locally advanced or metastatic HER2-positive breast cancer

Perjeta is given as an intravenous (IV) infusion in a hospital or cancer centre by trained medical staff. You will not administer this at home.

The first infusion takes 60 minutes. If well tolerated, subsequent infusions may be given over 30 minutes. It is given every three weeks (every 21 days).

You will be monitored during and for approximately one hour after each infusion

Your infusions are scheduled by your oncology team. Contact them if you need to reschedule an appointment.

In a clinical setting, any dosing error is managed immediately by medical staff.

Storage is handled by the treating clinic. Perjeta vials are stored in a refrigerator between 2°C and 8°C.

When used in combination with trastuzumab and chemotherapy, side effects may come from all components of the regimen.

Very common side effects:

• Diarrhoea: one of the most common effects with pertuzumab specifically. Tell your nurse if it is severe or persistent
• Nausea and vomiting
• Fatigue
• Hair loss (when used with chemotherapy)
• Low white blood cells (neutropenia)
• Infusion reactions: fever, chills, headache, or dizziness during the infusion
  
  

Serious side effects:

• Cardiac toxicity: pertuzumab, like trastuzumab, can reduce heart pumping function (LVEF). Heart function is monitored by echocardiogram before and during treatment

Blood tests and heart function checks are part of routine monitoring.

There are no specific major drug interactions with pertuzumab alone. However, it is always given with trastuzumab and usually chemotherapy, so the interaction considerations of those medicines apply.

Tell your oncologist about all medicines, supplements, and herbal products you are taking.

Why does adding Perjeta to Herceptin make a difference?

Trastuzumab (Herceptin) and pertuzumab (Perjeta) both target HER2, but at different locations on the protein. This means they block the HER2 signalling pathway through two different mechanisms simultaneously. Large clinical trials, including the CLEOPATRA study, showed that adding pertuzumab to trastuzumab and docetaxel significantly improved survival in HER2-positive metastatic breast cancer. This dual HER2 blockade strategy has since become the standard of care.

How long will I need to take Perjeta?

For metastatic breast cancer, Perjeta is continued as long as it is controlling the disease and you can tolerate it. For early breast cancer (adjuvant treatment), it is typically given for one year in combination with trastuzumab. Your oncologist will discuss the planned duration based on your specific situation.

Ace provides accurate and independent information medically reviewed on prescription medications. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment.