Targeted therapy

What is targeted therapy?

Targeted therapy is a type of drug treatment. It attacks specific cancer cell features, known as molecular targets, to stop the cancer growing and spreading.

Targeted therapy is sometimes called molecular targeted therapy and biological therapies.

How does targeted therapy work?

Targeted therapy drugs circulate throughout the body with each drug acting on a specific molecular target within or on the surface of cancer cells. As molecular targets are involved in the growth and survival of cancer cells, blocking them can kill cancer cells or slow their growth, while keeping damage to healthy cells at a minimum.

Targeted therapy drugs are used to control cancer growth and often cause the signs and symptoms of cancer to reduce or even disappear. The drugs may need to be taken long-term and will require you to have regular tests to monitor the cancer.

Targeted therapy is not suitable for everyone. Your doctors will test the cancer to see if the cells contain a particular molecular target. Different people with the same cancer type can receive different treatments based on their test results.

When is targeted therapy used?

The use of targeted therapy to treat cancer has improved survival rates for several types of cancer , and many people respond well.

Targeted therapy drugs have been approved for use in Australia for a number of cancer types. These include blood cancers such a lymphoma and leukaemia; common cancers like breast, bowel, lung and melanoma; and other cancers such as head and neck, cervical, liver, kidney, ovarian, stomach, pancreatic, sarcoma and thyroid.

Many targeted therapy drugs aren’t safe to use during pregnancy or breastfeeding. Talk to your doctor about contraception or if you become pregnant.

What are the different types of targeted therapy?

There are two main types of targeted therapy drugs:

• monoclonal antibodies – these are manufactured (synthetic) versions of immune system proteins called antibodies, which are part of the body’s natural defence against infections. The manufactured antibodies lock onto a protein on the surface of cells or surrounding tissues to interfere with the survival or growth of cancer cells.
• small molecular inhibitors – drugs that can get inside cancer cells and block certain enzymes and proteins that tell cancer cells to grow.

How is targeted therapy given?

Targeted therapy drugs are usually prescribed by a haematologist or medical oncologist. They are generally given in repeating cycles with periods of rest in between. Targeted therapy drugs may be given on their own or in combination of chemotherapy drugs. Targeted therapy drugs can be given as tablets that you swallow, through a drip into a vein in your arm or as an injection under your skin.

Some may be taken daily for months or even years – this will depend on the aim of treatment, how the cancer responds and any side effects you may have.

Will targeted therapy work?

Targeted therapy drugs will only work if the cancer contains the particular molecular target. Even if the cancer does contain the target, there is no guarantee the drug will kill the cancer cells. The response to targeted therapy varies depending on the cancer type and the molecular target. In some cancers, four out of five people considered suitable for a certain targeted therapy drug will respond.

What are the possible side effects of targeted therapy?

Targeted therapy aims to minimise harm to healthy cells but it can still have side effects. These will vary for each person depending on which drug you are taking and how your body responds. Some of the side effects from targeted therapy can include:

• skin problems such as redness, sensitivity to light, a rash or swelling and dry flaky skin
• itchy eyes with our without blurred vision
• fatigue
• headaches
• joint aches
• fever
• nausea
• diarrhoea
• high blood pressure.

Less commonly, some targeted therapy drugs may affect the way the heart, liver or thyroid works.

Most side effects are temporary,lasting from a few weeks to a few months and will gradually improve over time or after you stop taking the medication. You may experience several side effects or none at all. Discuss ways to manage any side effects you may be experiencing with your treatment team.

Where can I get reliable information?

Talk to your doctors about any concerns you have about targeted therapy or any side effects you experience. You can also call Cancer Council 13 11 20 for more information.