Targeted and immunotherapy drugs for secondary breast cancer

Targeted cancer drugs work by targeting the differences in cancer cells that help them to grow and survive.

Immunotherapy uses our immune system to attack the cancer.

There are different types of targeted and immunotherapy drugs for secondary breast cancer. They are usually grouped depending on the way they work, although some of these drugs work in more than one way.

When you might have these drugs

You might have these drugs with other types of treatment, for example chemotherapy. 

Not all the targeted and immunotherapy drugs will be suitable for you. You may only be able to have a particular drug if other drugs haven’t worked, or your breast cancer cells have certain receptors. 

For secondary breast cancer you might have these drugs to:

•    relieve symptoms 
•    reduce the size of the cancer 
•    improve your daily quality of life 

There is a lot of research looking at targeted drugs for secondary breast cancer and you may hear about new drugs as they become available. Do ask your doctor or nurse if you have any questions, they will explain which treatment is best for you.

How you have targeted and immunotherapy drugs

How you have this treatment depends on the individual drug. You have them as:

  • a drip in your arm
  • an injection under the skin
  • a tablet


One type of targeted drug is trastuzumab, also known by its brand names, Herceptin, Herzuma and Ontruzant. 

It's a monoclonal antibody. Monoclonal antibodies attach to proteins on or in cancer cells.

Diagram showing a monoclonal antibody attached to a cancer cell

Trastuzumab is a treatment for cancers that have large amounts of a protein called human epidermal growth factor receptor 2 (HER2). This is called HER2 positive breast cancer. 

Between 15 and 20 out of every 100 people with secondary breast cancer (between 15 to 20%) have HER2 positive breast cancer. A test on a sample of your cancer (biopsy Open a glossary item) will show if it's HER2 positive. 

You might have trastuzumab:

  • on its own
  • with chemotherapy such as paclitaxel
  • with hormone therapy if you have hormone receptor positive breast cancer 
  • with another targeted drug called pertuzumab and a chemotherapy 
  • with other drugs as part of a clinical trial

Trastuzumab deruxtecan (Enhertu) 

This treatment is made up of 2 drugs, Trastuzumab, and a chemotherapy drug called deruxtecan.

You might have this if you have HER2 positive breast cancer that:

•    cannot be removed by surgery
•    has spread to other parts of the body (secondary breast cancer)

It's for people who have already had 2 or more treatments for HER2 positive breast cancer.

Trastuzumab tucatinib and capecitabine

This treatment is a combination of three drugs:

  • trastuzumab
  • tucatinib - a type of targeted drug called a tyrosine kinase inhibitor Open a glossary item
  • capecitabine - a chemotherapy drug

You might have these drugs if you have HER2 positive breast cancer that has spread to:

•    surrounding tissue (locally advanced) or
•    other parts of the body

You must have already had two or more treatments for HER2 positive breast cancer before having this treatment.

Pertuzumab (Perjeta)

Pertuzumab targets the HER2 protein but blocks a different part of the protein than trastuzumab. 

You have pertuzumab with trastuzumab and a chemotherapy drug called docetaxel. The organisations within the UK that decide which treatments should be available within the NHS have approved it for people:

  • who have HER2 positive breast cancer that has spread
  • who haven't previously had anti HER2 treatment or chemotherapy for their advanced breast cancer
  • whose cancer has come back in or near the breast and surgery isn't possible

Doctors are waiting for the results of several trials looking at pertuzumab with different drugs for secondary breast cancer.

Denosumab (Prolia, Xgeva)

Denosumab is a type of monoclonal antibody.

When cancer spreads to the bones it can cause pain and weaken them. Your doctor may suggest you have denosumab. It can strengthen the bones to lower the risk of fractures and help to control pain.

Everolimus (Afinitor)

Everolimus is a type of cancer growth blocker. It stops some cancer cells from dividing and growing.

This is for secondary breast cancer that is hormone receptor positive and HER2 negative.

You have this drug if you are past the menopause (post menopausal). You take it with a hormone therapy drug called exemestane.

Palbociclib (Ibrance), ribociclib (Kisqali) and abemaciclib (Verzenio)

These are all a type of targeted drug called a cancer growth blocker. They can help to control the growth of breast cancer cells and slow it down.

You may have one of these drugs together with a type of hormone therapy. 

These drugs are for women with secondary breast cancer whose cancer is:

•    hormone receptor positive 
•    HER2 negative 

Trastuzumab emtansine (Kadcyla)

Trastuzumab emtansine is a combination of 2 drugs - trastuzumab and emtansine. It is also known by its brand name, Kadcyla (pronounced cad-sigh-lah].

It is a treatment for HER2 positive breast cancer that has come back or spread to other parts of the body.

You may have this if:

  • you have HER2 positive breast cancer and surgery is not possible 
  • you have had trastuzumab and a type of chemotherapy called a taxane, either as separate treatments or given together 
  • the breast cancer had come back (recurred) during treatment for early breast cancer or within 6 months of finishing treatment for early breast cancer

Atezolizumab (Tecentriq) with nab paclitaxel (Abraxane)

Atezolizumab is a type of immunotherapy drug. It works by helping the immune system recognise and attack cancer cells. You might also hear it called a monoclonal antibody or checkpoint inhibitor. 

Nab paclitaxel is a chemotherapy drug. 

You might have this drug combination if you have all the following:

•    your breast cancer is triple negative
•    it is not possible to remove the cancer with surgery
•    you have not had chemotherapy for advanced breast cancer before
•    you have a high level of a protein called PDL1

Targeted drug treatments for men with breast cancer

Because breast cancer is very rare in men, most trials into targeted drugs for breast cancer have only been carried out in women. 

Your doctor will check your cancer cells for proteins called HER2 receptors. But these are rarely found in male breast cancer. If your cancer cells have a lot of these receptors, your doctor will prescribe trastuzumab (Herceptin) or a similar drug.

Side effects

Everyone is different and the side effects vary from person to person. You might have a few side effects. And they may be mild or more severe. The side effects you have depend on:

  • which drug you have
  • whether you have it alone or with other drugs
  • the amount of drug you have (the dose)
  • your general health

A side effect may get better or worse during your course of treatment. Or more side effects may develop as the treatment goes on. For more information about the side effects of your treatment, go to the individual drug pages.

Do contact your doctor or nurse if you have any side effects.


Researchers are looking at different types of targeted drugs for secondary breast cancer.

The drugs are being combined with chemotherapy or other types of drugs to see if they improve how well they work as a treatment.

When you go home

Treatment with targeted drugs for secondary breast cancer can be difficult to cope with. You should have a contact number for your advice line if you have any questions or problems at home. Ask your healthcare team if you don’t have this.

It is important to contact them as soon as possible if you have side effects.

For general information you can call the Cancer Research UK nurses on freephone 0808 800 4040. The lines are open Monday to Friday, from 9am to 5pm.
Last reviewed: 
09 Mar 2021
Next review due: 
09 Mar 2024
  • Electronic Medicines Compendium
    Accessed March 2021

  • Scottish Medicines Consortium (SMC)

    Various guidance, accessed  November 2020

  • Advanced breast cancer: diagnosis and treatment
    National Institute of Health and Care Excellence (NICE), 2009 (updated 2017)

  • ESMO International Consensus Guidelines for Advanced Breast Cancer 

    F Cardoso and others

    Annals of Oncology, 2018. Volume, 29, Pages 1634–1657.

  • National Institute for Health and Care Excellence (NICE)

    Various guidance, accessed November  2020

  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact with details of the particular issue you are interested in if you need additional references for this information.

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