Common questions about targeted therapy

How is targeted therapy different to chemotherapy?

Targeted therapy and chemotherapy are both types of systemic treatment, but they work in different ways.

Chemotherapy drugs affect all cells that multiply quickly. This means the drugs can kill cancer cells and also damage other cells that multiply quickly, such as healthy cells in the mouth, stomach, bone marrow or hair. This is why chemotherapy side effects may include mouth ulcers, nausea, low numbers of blood cells (leading to infections or anaemia) and hair loss.

Targeted therapy drugs focus on the cancer cells, while limiting damage to healthy cells. Many people experience fewer side effects with targeted therapy. Some side effects, however, can be serious. Sometimes, the target is on healthy cells as well as cancer cells, and this can lead to particular side effects. For example, the EGFR gene may be on healthy skin cells as well as the cancer cells, so the targeted therapy can cause a rash.

Will targeted therapy work?

The cancer must contain the particular target or the drug won’t work. The response to targeted therapy varies widely. In some cancers, 4 out of 5 people assessed as suitable for a particular targeted therapy drug will respond. For other cancers, the rate of success is much lower. This is due to a range of factors, including how many of the cancer cells carry the target.

Cancer cells can eventually stop responding to a targeted therapy drug even if it works at first. If this happens, you may be offered another targeted therapy drug or a different type of treatment. Less commonly, a targeted therapy drug may cause serious side effects and the treatment plan will need to be adjusted (e.g. a lower dose or different drug may be tried).

How do I get targeted therapy?

Ask your cancer specialist if there is a suitable targeted therapy for you. This will depend on the type and stage of the cancer. Your specialist may also need to test the cancer to see if one of the currently available drugs is an option. If you have not already had surgery or a biopsy, you may need to have a biopsy so a tissue sample can be collected.

Many more targeted therapy and other new drugs are being studied in clinical trials. Talk with your specialist about the latest developments and whether there are any trials that might be right for you.

How is targeted therapy given?

Targeted therapy is usually prescribed by a medical oncologist or haematologist. It may be given on its own or combined with chemotherapy or other types of cancer drugs. Some targeted therapy drugs are given in repeating cycles, with rest periods in between. Others are taken every day without any breaks.

Cancer treatments are usually given in line with protocols that set out which drugs to have, how much and how often. Your specialist may need to adjust the protocols to your individual situation. You can find information about protocols for targeted therapy and other cancer drugs at the NSW Government's eviQ.

Targeted therapy is given in different ways:

• as tablets or capsules that you can swallow
• as an intravenous (IV) infusion into a vein, either through a drip in your arm or into a port (a small device inserted under the skin of the chest or arm)
• as an injection under the skin.

When targeted therapy is given as an infusion, some people react to the infusion process (e.g. skin rashes, nausea, difficulty breathing). Reactions can occur during the infusion or several hours afterwards. You will be monitored and may be given medicines to help prevent this. Reactions are more common with the first couple of infusions, so they may be given at a slower rate than later treatments.

How long you have targeted therapy depends on the aim of the treatment, how the cancer responds and any side effects you may have. In many cases, targeted therapy tablets or capsules need to be taken daily for many months or even years. Your treatment team can give you more details.

In some cases, you may need to take special precautions to protect other people in your household while you are having targeted therapy. Talk to your doctor about any safety measures that you may need to take.

How much will it cost?

The Pharmaceutical Benefits Scheme (PBS) covers most of the cost of many prescription medicines, including some targeted therapy drugs. Medicines not on the PBS are usually expensive, but you may be able to receive them as part of a clinical trial or at a reduced cost through a compassionate access program.

How will I know if targeted therapy is working?

You will have regular check-ups with your doctor, blood tests and different types of scans to see whether the cancer has responded to treatment with targeted therapy.

A good response from targeted therapy will make a cancer shrink or even disappear completely from scans. In some cases, the cancer remains stable, which means it doesn’t grow in size on scans, but also does not shrink or disappear.

People with stable disease can live for a long time and have a good quality of life.