Targeted cancer drugs

Targeted cancer drugs work by targeting the differences in cancer cells that help them to grow and survive. There are many different types of targeted drugs.

When you might have targeted treatment

Targeted cancer drugs are used in different situations to treat breast cancer. You might have this treatment :

  • before surgery - to shrink a cancer
  • after surgery - to reduce the risk of the cancer coming back

You might also have this treatment if your cancer comes back (recurs) or if you have breast cancer that has spread to another part of the body (secondary breast cancer). You may have it on its own, with other targeted drugs, or with other treatments such as chemotherapy.

There are many different types of targeted drugs. We describe some of the drugs used for breast cancer below.

Trastuzumab (Herceptin, Herzuma, Ontruzant)

Trastuzumab is also known by its brand name 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

You have this drug if your cancer cells have receptors for HER2 protein Open a glossary item. HER2 makes the cancer cells grow and divide. Between 13 to 20 out of every 100 women with breast cancer (between 13 to 20%) have large amounts of the HER2 protein Open a glossary item. These breast cancers are called HER2 positive cancers. Breast cancers without large amounts of this protein are called HER2 negative cancers.

Your doctor will test your cancer cells to check for these receptors.

You might have trastuzumab alone or in combination with chemotherapy or another type of targeted drug. You might have it before or after surgery and with other treatments, such as radiotherapy. 

Trastuzumab emtansine (Kadcyla) is a combination of trastuzumab and a chemotherapy drug called emtansine. It is a treatment for HER2 positive early stage breast cancer Open a glossary item after surgery. But only in people whose cancer didn’t fully shrink following drug treatment before surgery.

Trastuzumab emtansine works in two ways. The trastuzumab finds and attaches itself to the HER2 protein on the surface of the cancer cell. The emtansine then goes inside the cancer cell to destroy it.

Pertuzumab (Perjeta)

Pertuzumab is also called Perjeta. It is also a type of monoclonal antibody.

You might have a combination of trastuzumab and pertuzumab before surgery if you have HER2 positive cancer that is one of the following:

  • early breast cancer that is at high risk of coming back
  • locally advanced breast cancer Open a glossary item
  • inflammatory breast cancer - a rare type of breast cancer 

It is also a treatment with trastuzumab and chemotherapy following surgery for early breast cancer.

Neratinib (Nerlynx)

Neratinib belongs to a group of drugs called cancer growth blockers. They work by blocking the signalling processes that cancer cells use to divide.

You have neratinib treatment for early stage breast cancer Open a glossary item that is hormone receptor positive and HER2 positive. It is for people who have already had treatment with trastuzumab within the last year.

Other targeted drugs for locally advanced breast cancer

There are other cancer growth blockers that your doctor might use to treat locally advanced breast cancer Open a glossary item. You have one of these drugs with a hormone therapy drug, so either an aromatase inhibitor Open a glossary item or fulvestrant. These include:

  • palbociclib
  • ribociclib
  • abemaciclib

These drugs are for breast cancer that is hormone receptor positive and HER2 negative. You have tests on your breast cancer cells to check for this.

Secondary breast cancer

Some of these drugs and other targeted drugs are used to treat secondary breast cancer.

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.


Researchers are looking at:

  • new targeted and immunotherapy drugs
  • different combinations of these drugs with other treatments 

Immunotherapy uses our immune system to fight cancer. It works by helping the immune system recognise and attack cancer cells.

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