A HER2-targeted antibody
Pertuzumab
A targeted antibody for HER2-positive breast cancer, given with trastuzumab and chemotherapy by oncology teams.
What is Pertuzumab?
Pertuzumab is a targeted cancer medicine (a monoclonal antibody) used for HER2-positive breast cancer, where the cancer makes too much of a growth protein called HER2. It is given by a specialist oncology team as a drip into a vein, almost always together with trastuzumab and chemotherapy, because the combination works better than any one alone. As with trastuzumab, it can affect how well the heart pumps, so your team checks your heart with scans. Diarrhoea and infusion reactions are common, so you are watched closely and supported during treatment.
Education and reference only. This is a plain-language guide to Pertuzumab — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Pertuzumab is a monoclonal antibody, a laboratory-made protein that targets the HER2 growth protein on breast cancer cells. It is used for HER2-positive breast cancer and is given alongside trastuzumab and chemotherapy, a combination that blocks HER2 in two complementary ways. It is not a tablet; it is given by oncology specialists as a drip into a vein. The brand name is Perjeta, and it is sometimes given as a combined injection together with trastuzumab.
How it works
HER2 is a protein that signals cancer cells to grow and divide, and pertuzumab attaches to a different part of HER2 than trastuzumab does. By blocking HER2 from teaming up with its partner proteins, pertuzumab stops one of the main growth signals, and when it is used with trastuzumab the two antibodies block HER2 more completely. Adding chemotherapy, which kills dividing cells in another way, makes the whole combination more effective. Because HER2 plays a small part in heart muscle, the combination can affect heart pumping, which is why heart scans are done.
Company & origin
Originated / developed by: Roche.
A targeted cancer antibody used in the UK by oncology teams for HER2-positive breast cancer, given alongside trastuzumab and chemotherapy.
Practical use
How to take Pertuzumab
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given by your oncology team as a drip into a vein, usually alongside trastuzumab and chemotherapy; it is never taken as a tablet.
- You may be given supportive medicines before the drip to reduce the chance of an infusion reaction.
- Tell your team promptly if you have diarrhoea, as this is common and can be treated to keep you well and hydrated.
- Attend all your heart scans and blood tests, as the heart is monitored throughout the planned course.
- Report breathlessness, swollen ankles or a fast or irregular heartbeat to your team straight away.
Weighing it up
Advantages & disadvantages of Pertuzumab
Advantages
- Blocks HER2 in a different way to trastuzumab, so the two together work more effectively.
- Used with trastuzumab and chemotherapy, it can improve outcomes in HER2-positive breast cancer.
- Can be given as a combined injection with trastuzumab in some cases, which is quicker.
Disadvantages
- Diarrhoea is common and can sometimes be troublesome, needing treatment to manage it.
- Can affect the heart's pumping action, so regular heart scans are required.
- Only suitable for HER2-positive breast cancer and is given as drips rather than tablets.
Practical use
Good to know
Pertuzumab is almost always given together with trastuzumab and chemotherapy rather than on its own, so many of the cautions overlap. The most important points are the effect on the heart, which means you will have heart scans before and during treatment, and diarrhoea, which is very common and can sometimes be marked, so tell your team early so it can be managed. Infusion reactions such as chills, fever or flushing can also happen, especially with the first doses, so you are watched closely and may be given supportive medicines. It only helps cancers that are HER2-positive, confirmed by testing the cancer. It is avoided in pregnancy because it can harm the developing baby, so effective contraception is important.
Who should not take it / use with caution
- People with significant existing heart problems may not be suitable, or will need close monitoring.
- It is avoided in pregnancy because it can harm the developing baby, so effective contraception is advised.
- Anyone who has had a serious allergic reaction to pertuzumab should not receive it again.
Monitoring
- Heart scans (such as echocardiograms) before and during treatment to check the heart's pumping action.
- Watching for and managing diarrhoea, and supporting hydration if needed.
- Regular blood tests, infusion-reaction checks and review of how the cancer is responding.
Side effects
- Diarrhoea, which is common and can sometimes be marked; tell your team so it can be managed.
- Infusion reactions such as chills, fever and flushing, mainly with early doses.
- A reduced heart pumping action, tiredness, rash, mouth soreness and a higher infection risk with chemotherapy.
Key interactions
- Given as a planned combination with trastuzumab and chemotherapy rather than as an accidental interaction.
- Chemotherapy drugs that can also affect the heart may add to the strain, so the combination is planned carefully.
- Tell your team about all your medicines, including any heart medicines, so monitoring can be adjusted.
Available as: Given by oncology teams as a drip into a vein, or as a combined injection with trastuzumab in some cases.
Answers
Pertuzumab: frequently asked questions
Why is pertuzumab given with trastuzumab?
The two antibodies block the HER2 growth protein in different, complementary ways, so giving them together with chemotherapy works better than any one alone.
Will it upset my stomach?
Diarrhoea is common with pertuzumab and can sometimes be marked, so tell your team early; it can usually be managed with simple treatments and good hydration.
Does it affect the heart like trastuzumab?
Yes, the combination can affect how strongly the heart pumps, so you will have heart scans before and during treatment and the medicine may be paused if needed.
Is pertuzumab chemotherapy?
No. It is a targeted antibody against HER2, given alongside chemotherapy, which works in a different way to kill dividing cells.
Can I have it if I might become pregnant?
It can harm a developing baby, so it is avoided in pregnancy and effective contraception is advised during and for a time after treatment; discuss this with your team.
Authoritative sources
- BNF
- NICE CKS
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