Gefitinib (Iressa®)

What is gefitinib? Back to top

Gefitinib belongs to a group of medicines called epidermal growth factor receptor inhibitors, also known as EGFR inhibitors.

How it works Back to top

Gefitinib blocks (inhibits) a protein called an epidermal growth factor receptor. It's involved in the growth and spread of cancer cells.

EGFRs are structures on the surface of many types of cancer cells. The receptors allow the epidermal growth factor (a protein present in the body) to attach to them. When the epidermal growth factor (EGF) attaches to the receptor, it causes an enzyme called tyrosine kinase (TK) to trigger chemical processes inside the cell to make it grow and divide.

Gefinitib attaches itself to the EGF receptor on the cell and prevents the receptor from being activated. This stops the cells from dividing. Gefinitib therefore has the potential to stop the cancer cells from growing.

When it is used Back to top

Gefitinib is used to treat some people with non-small cell lung cancer (NSCLC). It only works for NSCLCs that have changes called EGFR mutations on the surface of their cells. EGFR mutations are most likely in NSCLC in:

• women
• people who have never smoked
• people with adenocarcinoma
• people of Asian ethnicity.

Tests may be done to check the level of EGFR. These will tell if you're likely to benefit from gefitinib. Testing can be done at the time the cancer is diagnosed, or samples of cancer cells from previous biopsies or surgery may be used.

The National Institute for Health and Clinical Excellence (NICE|) currently gives advice on which new drugs or treatments should be available on the NHS. They recommend gefitinib as a possible first treatment for people with NSCLC that is EGFR positive and has spread to surrounding tissues or other parts of the body.

How it is given Back to top

Gefinitib is taken as a tablet once a day. You should take the tablet at the same time each day.

Possible side effects Back to top

Each person’s reaction to cancer treatment is different. Some people have very few side effects while others may experience more. The side effects described here won't affect everyone having this treatment.

We've outlined the most common side effects but haven't included those that are rare and therefore unlikely to affect you. If you notice any effects that aren't listed below, discuss them with your doctor or specialist nurse.

Skin changes

An acne-like rash that mainly affects the head, chest and back is the most common side effect of gefitinib. This usually begins during the first 2-3 weeks of treatment and goes away once treatment ends.

Your skin may also become dry and itchy or feel tender and peel. Some people find that the nails on their hands or feet become red, sore and brittle.

Taking the following steps may help reduce the severity of skin changes, although they can’t prevent them altogether.

• Use tepid water and mild non-scented soap for bathing and washing.
• Avoid skincare products that contain alcohol.
• Don’t use anti-acne products, as they can dry your skin and make your symptoms worse.
• Sunlight can make skin symptoms worse. During treatment with gefitinib, and for several months afterwards, you will be more sensitive to the sun, and your skin may burn more easily than normal. You can still go out in the sun, but should wear a sun cream with a high sun protection factor (SPF) and cover up with clothing and a hat. If you are having radiotherapy, don't apply sunscreen to any skin in the area being treated.
• Moisturise your skin regularly and after bathing. Your doctor or specialist nurse can advise you on which moisturisers are best.
• Protect your hands and fingernails from detergents by wearing rubber gloves when washing dishes.

Let your doctor know as soon as possible if you develop skin or nail changes. They can prescribe treatment to help. In people who have more severe side effects, treatment with gefitinib can be stopped for a few days to allow their skin to recover. 

Hair changes

Your eyelashes may grow longer and more curly than usual. Men may notice they have less beard growth. You may notice your head and body hair is finer, curlier or more brittle.

Some people have hair thinning or hair loss|. If this happens, it usually develops gradually. These changes are usually temporary and gradually improve once treatment is over.

Diarrhoea

This can usually be easily controlled with medicine, but tell your doctor if it's severe or continues. It's important to drink plenty of fluids if you have diarrhoea|.

This can usually be easily controlled with medicine, but tell your doctor if it's severe or continues. It's important to drink plenty of fluids if you have .

Loss of appetite

A dietitian or specialist nurse at your hospital can giva advice about how to boost your appetite| and maintain your weight.

Feeling sick (nausea) and being sick (vomiting)

This is usually mild. Let your doctor know if it isn't controlled as they can prescribe effective anti-sickness medication|.

Tiredness

Some people feel tired| and lack energy while taking gefitinib.

Bleeding problems

Let your doctor know if you have nosebleeds or notice blood in your urine while taking gefitinib.

Eye problems

If you notice any change to your vision, or pain or redness of your eyes, let your doctor know immediately.

Breathing problems

Always let your doctor or nurse know about any side effects you have. There are usually ways in which they can be controlled or improved.

Additional information Back to top

• Keep the tablets in a safe place, out of the reach of children.
• Gefitinib may interact with other medicines, including some that are used to treat stomach ulcers, indigestion and epilepsy. It may also interact with the herbal remedy St John's Wort. Tell your doctor about any medications you are taking, including any non-prescribed drugs such as complementary or herbal therapies.
• If your doctor decides to stop the treatment, return any remaining tablets to the pharmacist. Don't flush them down the toilet or throw them away.
• If you are sick after taking the tablet, tell your doctor, as you may need to take another one.
• If you forget to take a tablet, take it as soon as you remember, as long as it is more than 12 hours before your next scheduled dose. If it is less than 12 hours, do not take the missed dose.
• It's not advisable to become pregnant or father a child while having this treatment, as it may harm the developing baby. It is important to use effective contraception.

References Back to top

This section has been compiled using information from a number of reliable sources including: 

• electronic Medicines Compendium (eMC). Summary of Product Characteristics (SPC): Gefitinib. (accessed 6 August 2010).
• TA129 Gefitinib for the first-line treatment of locally advanced or metastatic non-small-cell lung cancer. July 2010. National Institute for Health and Clinical Excellence (NICE).