This information is about a drug called lenalidomide. It is used to treat people with myeloma (a cancer of the plasma cell of the bone marrow).

Lenalidomide belongs to a new class of drugs called immunomodulatory drugs (IMiDs™). The exact way lenalidomide works is not completely understood at the moment. It affects the way the immune system works.

Lenalidomide also has the ability to block the development of new blood vessels. Making blood vessels is called angiogenesis. Cancer cells need to make new blood vessels so they can grow and spread.

Lenalidomide is usually given in combination with a steroid called dexamethasone to treat myeloma. It is also being researched in some other cancers including chronic myeloid leukaemia, and advanced renal cancer. Lenalidomide is also used to treat a type of anaemia known as myelodysplastic syndrome.

Lenalidomide is available as 5mg, 10mg, 15mg and 25mg capsules.

Lenalidomide capsules are swallowed whole with plenty of water once a day.

Each person's reaction to a cancer drug is different. Some people have very few side effects, while others may experience more. We have outlined the most common side effects. However, we have not included those that are very rare and therefore extremely unlikely to affect you. If you notice any effects that you think may be due to the drug but which are not listed here, please discuss them with your doctor or nurse.

Lowered resistance to infection Lenalidomide can reduce the production of white blood cells by the bone marrow, making you more prone to infection. Your blood counts will be monitored while you are taking lenalidomide.

Contact your doctor or the hospital straightaway if:

• your temperature goes above 38ºC (100.5ºF)
• you suddenly feel unwell (even with a normal temperature).

You will have a blood test before having more treatment to make sure that your cells have recovered. Occasionally it may be necessary to delay your treatment if the number of blood cells (the blood count) is still low.

Bruising or bleeding Lenalidomide can reduce the production of platelets (which help the blood to clot). Let your doctor know if you have any unexplained bruising or bleeding.

Risk of blood clots Lenalidomide may increase your risk of developing blood clots. These can be either a deep vein thrombosis (DVT) which is a clot in the leg, or a pulmonary embolism (PE), which is a clot in the lung. While taking lenalidomide you may also be given medication to thin your blood and help to prevent any clots forming. Let your hospital doctor know if you develop any pain, swelling or redness in one of your calves (a possible DVT), or if you notice any breathlessness or chest pain (a possible PE).

Rashes Lenalidomide can cause a rash, which may be itchy. Your doctor can prescribe treatment to help reduce this.

Constipation This can usually be relieved by drinking plenty of fluids (2–3 litres a day), eating a high-fibre diet and taking gentle exercise. Sometimes you may need to take laxatives to stimulate your bowel. These can be prescribed by your doctor.

Lethargy or sleepiness You may feel tired when taking lenalidomide. If you are sleepy, it is important not to drive or operate machinery. It may help to take the tablets in the evening.

If you have any questions about these or any other side effects, you can talk to your doctor or nurse. It is important to let them know if you have any symptoms or side effects that may be related to the treatment you are having.

Contraception Because lenalidomide can potentially cause serious birth defects it is very important not to become pregnant or father a child while taking this drug. Women will be asked to have a pregnancy test, to check that they are not pregnant. They will also be advised to use a highly effective form of contraception (such as implanted or injected contraception) as well as a barrier method (such as a condom or cap).

Men taking lenalidomide are advised to use a condom even if they have had a vasectomy.

• It is important to take your capsules at the right times. You must take them as directed by your doctor.
• Keep the capsules in a safe place where children cannot reach them, as lenalidomide could harm them.
• If your doctor decides to stop the treatment, return any remaining capsules to the pharmacist. Do not flush them down the toilet or throw them away.
• If you forget to take a capsule, do not take a double dose. Tell your doctor and keep to your regular dose schedule.
• If you are sick just after taking the tablet, tell your doctor, as you may need to take another one.
• Lenalidomide may interact with other medicines that you are taking. Let your doctor know what medications you are taking, including herbal medicines and those you have bought over the counter.

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

• Morgan GJ et al. Advance in oral therapy for multiple myeloma. Lancet Oncology. 2006; 7: 316-25.
• Nimer SD . Clinical management of myelodysplastic syndromes with interstitial deletion of chromosome 5q. Journal of Clinical Oncology, 2006, 24: 2576-82.
• Chanan-Khan A et al. Results of a phase II trial of lenalidomide (L) (Revlimid) in patients with relapsed chronic lymphatic leukemia (CLL ). Blood, 2005,135a, abst 447.
• Choueiri YK et al. Phase II trial of lenalidomide in patients with metastatic renal cell cancer. Cancer, 2006, 107: 2609-16.

For further references, please see the general bibliography.