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Generic name: alemtuzumabAL-em-TOOZ-ue-mab ]
Brand names: Campath, Lemtrada
Drug class: CD52 monoclonal antibodies

Medically reviewed by on Aug 22, 2022. Written by Cerner Multum.

What is Campath?

Campath is used to treat B-cell chronic lymphocytic leukemia in adults.

Lemtrada is used to treat relapsing forms of multiple sclerosis in people 17 years and older (including active secondary progressive disease), after at least two other medicines did not work or have stopped working.

Lemtrada will not cure MS, but it can make relapses occur less often. Lemtrada is not for use in treating clinically isolated syndrome.

Campath may also be used for purposes not listed in this medication guide.

Campath side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Get emergency medical help if you have symptoms of thrombotic thrombocytopenic purpura: purple spots on the skin or in the mouth, jaundice (yellowing of the skin or eyes), tiredness, fever, feeling short of breath, fast heart rate, speech or vision changes, confusion, seizure, dark or blood in your urine, stomach pain, nausea, vomiting, or diarrhea.

Campath may cause a brain infection that can lead to disability or death. Tell your doctor if you have problems with speech, thought, vision, or muscle movement. These symptoms can get worse quickly.

Some side effects may occur during or shortly after the injection. Tell your caregiver if you feel weak, feverish, chilled, dizzy, nauseated, light-headed, or have a rash, wheezing, chest pain, trouble breathing, swelling in your mouth or throat, or fast, slow, or irregular heartbeats.

Campath can cause your immune system to attack cells and organs in your body. This can lead to serious medical problems that may occur months to years after you receive Campath or Lemtrada. Call your doctor at once if you have:

Common side effects of Campath may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Campath can cause life-threatening side effects, including serious medical problems that may occur months to years after you receive Campath.

Before taking this medicine

You may not be able to use Campath if you are allergic to it, or if you have an active infection, o HIV (human immunodeficiency virus).

Tell your doctor if you have ever had:

Tell your doctor if you have never had chickenpox or if you have never received a varicella vaccine (Varivax). You may need to receive the vaccine and then wait 6 weeks before using Lemtrada.

Lemtrada may increase your risk of developing other types of cancer, such as melanoma, thyroid cancer, lymphoma, or leukemia. Ask your doctor about this risk.

You may need to have a negative pregnancy test before starting this treatment. Campath may harm an unborn baby. Use effective birth control to prevent pregnancy while receiving this medicine, and for at least 3 months after your last dose of Campath and for 4 months after your last dose of Lemtrada. Tell your doctor if you become pregnant.

If you use Campath while you are pregnant, make sure any doctor caring for your new baby knows that you used the medicine during pregnancy. Being exposed to Campath in the womb could affect your baby's vaccination schedule.

Campath may affect fertility (ability to have children) in both men and women. However, women should still use birth control to prevent pregnancy because this medicine can harm an unborn baby.

It may not be safe to breastfeed while using Campath. You should not breastfeed while using Campath, and for at least 3 months after your last dose.

How is Campath given?

Campath is given as an infusion into a vein. A healthcare provider will give you this injection. You will be watched closely for up to 2 hours or longer after the infusion, to make sure you do not have a serious reaction.

Campath is usually given 3 times per week for 12 weeks. Lemtrada is usually given in 2 or more treatment courses, separated by 1 year. Your doctor will determine how long to treat you and the number of courses you need. Campath must be given slowly. The Campath infusion can take 2 hours to complete. The Lemtrada infusion can take 4 hours to complete.

You may be given other medicines to help prevent certain side effects or infections. Use these medicines for the full prescribed length of time.

Campath affects your immune system. You may get infections more easily, even serious or fatal infections. You will need frequent medical tests, and your next dose may be delayed based on the results.

You should have a human papilloma virus (HPV) screening every year if you are a female.

Campath can have long lasting effects on your body. You may need medical tests for up to 2 months after you stop using Campath, or 4 years after you stop using Lemtrada.

What happens if I miss a dose?

Call your doctor for instructions if you miss an appointment for your Campath.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while receiving Campath?

Do not receive a "live" vaccine while using Campath. The vaccine may not work as well or you could develop a serious infection. Live vaccines include measles, mumps, rubella (MMR), rotavirus, typhoid, yellow fever, varicella (chickenpox), zoster (shingles), and nasal flu (influenza) vaccine.

While being treated with Lemtrada, avoid foods that may be a source of Listeria infection, or heat them thoroughly before consuming. This includes deli meat, undercooked meat, seafood, poultry, unpasteurized dairy products, or soft cheeses.

What other drugs will affect Campath?

Tell your doctor about all your other medicines, especially drugs that weaken the immune system such as cancer medicine, or medicines to prevent organ transplant rejection.

Other drugs may affect Campath, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Frequently asked questions

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.