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Alemtuzumab (MabCampath)

Find out what alemtuzumab is, how you have it and other important information about having alemtuzumab.

Alemtuzumab is a type of targeted cancer drug. It is a treatment for chronic lymphocytic leukaemia (CLL) and skin lymphoma. It is also used to treat other non cancer diseases such as multiple sclerosis (MS).

Alemtuzumab is pronounced al-em-TOOZ-oo-mab.

How alemtuzumab works

Alemtuzumab targets a protein called CD52 on the surface of a type of white blood cell called mature B lymphocytes. In some cancers, the B lymphocytes are abnormal. The alemtuzumab sticks to all the CD52 proteins it finds. Then the immune system picks out the marked cells and kills them.

B cells in an early stage of development don’t have the CD52 protein and so they aren’t killed. This means they can then produce healthy B cells. So, the number of healthy B cells in the body is back to normal within a few months of treatment.

How you have it

You have alemtuzumab into your bloodstream (intravenously). 

You can have the drug through a thin short tube (a cannula) that goes into a vein in your arm each time you have treatment.

Or you might have it through a long line: a central line, a PICC line or a portacath.

These are long plastic tubes that give the drug into a large vein in your chest. The tube stays in place throughout the course of treatment.

When you have it

For chronic lymphocytic leukaemia (CLL)

You have alemtuzumab as a drip (an infusion) over 2 hours. 

You start on a low dose and the doctor gradually increases the dose until you are having the recommended amount. This is called dose escalation. Doctors do this because some people react to the treatment. By gradually increasing the dose you are less likely to react.

While you are having dose escalation you have treatment daily. It takes between 3 days and a week to reach the right dose.

Then you have treatment 3 times a week, for between 4 and 12 weeks. 

As part of a stem cell transplant

You usually have the same dose of alemtuzumab, for 5 days. 


You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.

Side effects

Important information

Other medicines, foods and drink

Cancer drugs can interact with some other medicines and herbal products. Tell your doctor or pharmacist about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies.

Pregnancy and contraception

This drug may harm a baby developing in the womb. It is important not to become pregnant or father a child while you are having treatment with this drug and for at least 6 months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.


You may not be able to become pregnant or father a child after treatment with this drug. Talk to your doctor before starting treatment if you think you may want to have a baby in the future. Men may be able to store sperm before starting treatment. Women may be able to store eggs or ovarian tissue but this is rare.


Don't breastfeed during this treatment and for several months afterwards because the drug may come through in the breast milk.

Treatment for other conditions

Always tell other doctors, nurses, pharmacists or dentists that you’re having this treatment if you need treatment for anything else, including teeth problems.


Don’t have immunisations with live vaccines while you’re having treatment and for up to 12 months afterwards. The length of time depends on the treatment you are having. Ask your doctor or pharmacist how long you should avoid live vaccinations.

In the UK, live vaccines include rubella, mumps, measles, BCG, yellow fever and the shingles vaccine (Zostavax).

You can:

  • have other vaccines, but they might not give you as much protection as usual
  • have the flu vaccine (as an injection)
  • be in contact with other people who have had live vaccines as injections

Avoid close contact with people who have recently had live vaccines taken by mouth (oral vaccines) such as oral polio or the typhoid vaccine.

This also includes the rotavirus vaccine given to babies. The virus is in the baby’s poo for up to 2 weeks and could make you ill. So avoid changing their nappies for 2 weeks after their vaccination if possible. Or wear disposable gloves and wash your hands well afterwards.

You should also avoid close contact with children who have had the flu vaccine nasal spray. You should do so for 2 weeks following their vaccination if you have a severely weakened immune system.

More information about this treatment

For further information about this treatment go to the electronic Medicines Compendium (eMC) website.

You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.

Information and help