Targeted cancer drugs for thyroid cancer

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

They are a treatment for thyroid cancer when the cancer has spread or other treatments stop working. Targeted cancer drugs don't cure thyroid cancer. But they might help to shrink or control the growth of your cancer and to reduce symptoms.

Targeted cancer drugs for thyroid cancer include:

• lenvatinib (Lenvima)
• cabozantinib (Cometriq)
• selpercatinib (Retsevmo)
• dabrafenib (Tafinlar)
• trametinib (Mekinist)

When you might have targeted drugs for thyroid cancer

Most thyroid cancers can be treated with surgery and radioactive iodine therapy. You might have targeted drugs for thyroid cancer if: 

• other treatments are not an option or no longer work
• the cancer begins to grow outside of the thyroid gland or spread to another part of your body

Whether you are able to have one of these drugs might also depend on treatments you have already had. Your doctor will discuss targeted drugs with you if they think this treatment could help you.

Tests on your cancer cells

For anaplastic thyroid cancer, you might need to have a test using some of your cancer cells. This is to find out whether the targeted cancer drugs are likely to work. Your doctor looks at a sample of your cancer to do this.

These tests look for changes in certain proteins or genes. For anaplastic thyroid cancer, they look for changes in the BRAF gene.

This is not the case for all targeted drugs, and you don’t need this test for other types of thyroid cancer.

Tyrosine kinase inhibitors (TKIs)

There are many different types of targeted cancer drugs. These are grouped according to the way they work. For thyroid cancer, doctors use a type of targeted drug called tyrosine kinase inhibitors (TKIs).

TKI’s block a cancer cell chemical messenger called tyrosine kinase. This changes the way the cells signal to each other and can control the growth of cancer cells.

Some TKIs are able to block more than one kinase protein. These are called multi-kinase inhibitors. These drugs can also stop cancers from forming new blood vessels, which they need to be able to grow.

Doctors use different types of TKI drugs, depending on your type of thyroid cancer:

For differentiated thyroid cancer

Doctors might offer you lenvatinib (Lenvima). Another option is sorafenib (Nexavar) but this isn't available in all parts of the UK.

For medullary thyroid cancer

Your doctor might suggest:

• cabozantinib (Cometriq) - this isn't available in all parts of the UK
• selpercatinib (Retsevmo)

Another drug called vandetanib (Caprelsa) isn't widely used any more. Doctors are more likely to use one of the other drug options.

For anaplastic thyroid cancer

You might have a targeted drug if your cancer has changes to the BRAF gene.  You might have the following drugs together:

• dabrafenib (Tafinlar)
• trametinib (Mekinist)

How you have targeted cancer drugs

Most of the targeted cancer drugs for thyroid cancer are tablets or capsules that you take by mouth. Your treatment team will tell you how often and when you need to take these.

You may be given important instructions about how to handle and store your drug at home.

Side effects

Everyone is different and the side effects vary from person to person. 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.

When you go home

Treatment with immunotherapy or targeted cancer drugs can be difficult to cope with for some people. Your nurse will give you a number to call (advice line) if you have any problems at home.