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Alemtuzumab (Intravenous)

Generic name: alemtuzumab (al-em-TOOZ-oo-mab)
Drug class: CD52 monoclonal antibodies

Medically reviewed by Last updated on March 2, 2021.

Intravenous route(Solution)

Cytopenias, Infusion-related Reactions, and InfectionsSerious, including fatal, cytopenias, infusion-related reactions, and infections can occur.Limit doses to 30 mg (single) and 90 mg (cumulative weekly); higher doses increase risk of pancytopenia.Escalate dose gradually and monitor patients during infusion. Withhold therapy for Grade 3 or 4 infusion-related reactions.Administer prophylaxis against Pneumocystis jirovecii pneumonia (PCP) and herpes virus infections .

Intravenous route(Solution)

Autoimmunity, Infusion Reactions, Stroke, and MalignanciesAlemtuzumab causes serious, sometimes fatal, autoimmune conditions such as immune thrombocytopenia and anti-glomerular basement membrane disease. Monitor complete blood counts with differential, serum creatinine levels, and urinalysis with urine cell counts before starting treatment and then at monthly intervals until 48 months after the last does of alemtuzumab.Alemtuzumab causes serious and life-threatening infusion reactions. Alemtuzumab must be administered in a setting with appropriate equipment and personnel to manage anaphylaxis or serious infusion reactions. Monitor patients for two hours after each infusion. Make patients aware that serious infusion reactions can also occur after the 2-hour monitoring period.Serious and life-threatening stroke (including ischemic and hemorrhagic stroke) has been reported within 3 days of alemtuzumab administration. Instruct patients to seek immediate medical attention if symptoms of stroke occur.Alemtuzumab may cause an increased risk of malignancies, including thyroid cancer, melanoma, and lymphoproliferative disorders. Perform baseline and yearly skin exams.Because of the risk of autoimmunity, infusion reactions, and malignancies, alemtuzumab is available only through restricted distribution under a Risk Evaluation Mitigation Strategy (REMS) Program. Call 1-855-676-6326 to enroll in the alemtuzumab REMS program .

Commonly used brand name(s)

In the U.S.

  • Campath
  • Lemtrada

Available Dosage Forms:

  • Solution

Therapeutic Class: Antineoplastic Agent

Pharmacologic Class: Monoclonal Antibody

Uses for alemtuzumab

Alemtuzumab injection is used to treat the relapsing forms of multiple sclerosis (MS), including relapsing-remitting disease and active secondary progressive disease. Alemtuzumab will not cure MS, but it may slow some of the disabling effects and decrease the number of relapses of the disease. It should only be used when 2 or more other medicines to treat MS did not work well.

Alemtuzumab is available only under a restricted distribution program called the Lemtrada® REMS (Risk Evaluation and Mitigation Strategy) Program.

Before using alemtuzumab

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For alemtuzumab, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to alemtuzumab or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Appropriate studies have not been performed on the relationship of age to the effects of alemtuzumab injection in children younger than 17 years of age. Use is not recommended in children. Safety and efficacy have not been established.


Appropriate studies on the relationship of age to the effects of alemtuzumab injection have not been performed in the geriatric population. However, geriatric-specific problems that would limit the usefulness of alemtuzumab injection in the elderly are not expected.


There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving alemtuzumab, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using alemtuzumab with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

  • Measles Virus Vaccine, Live
  • Mumps Virus Vaccine, Live
  • Rotavirus Vaccine, Live
  • Rubella Virus Vaccine, Live
  • Varicella Virus Vaccine, Live
  • Zoster Vaccine, Live

Using alemtuzumab with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Adenovirus Vaccine
  • Bacillus of Calmette and Guerin Vaccine, Live
  • Cholera Vaccine, Live
  • Dengue Tetravalent Vaccine, Live
  • Influenza Virus Vaccine, Live
  • Ozanimod
  • Poliovirus Vaccine, Live
  • Siponimod
  • Smallpox Vaccine
  • Tofacitinib
  • Typhoid Vaccine
  • Yellow Fever Vaccine

Interactions with food/tobacco/alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems

The presence of other medical problems may affect the use of alemtuzumab. Make sure you tell your doctor if you have any other medical problems, especially:

  • Autoimmune diseases (eg, Guillain-Barré syndrome, hemolytic anemia, pancytopenia, rheumatoid arthritis) or
  • Bleeding problems or
  • Heart or blood vessel disease or
  • Kidney disease or
  • Liver disease or
  • Lung disease or breathing problems (eg, pneumonitis) or
  • Thyroid disease—Use with caution. May make these conditions worse.
  • Clinically isolated syndrome (relapsing form of MS)—Use is not recommended in patients with this condition.
  • Human immunodeficiency virus (HIV) infection or
  • Infection, active—Should not be used in patients with these conditions.
  • Infection (eg, chickenpox, fungi, herpes, tuberculosis)—May decrease your body's ability to fight infection.

Proper use of alemtuzumab

A nurse or other trained health professional will give you alemtuzumab in a medical facility. It is given through a needle placed into one of your veins.

Alemtuzumab is usually given for 2 treatment courses. You will receive alemtuzumab for 5 consecutive days for the first treatment course and for 3 consecutive days about 1 year later for your second treatment course. Each treatment usually takes about 4 hours per day.

Your doctor may ask you to stay for at least 2 hours after each treatment to check for unwanted effects.

You will receive steroid medicines right before starting treatment to prevent allergic reactions and for the first 3 days of each treatment course. You will also be given antiviral medicines starting on the first day of each treatment course and for at least 2 months after treatment. These medicines are given to prevent infections caused by the herpes virus.

It is very important that you understand the requirements of the Lemtrada® REMS program, and become familiar with the Lemtrada® Medication Guide. Read and follow these instructions carefully. Ask your doctor if you have any questions.

Precautions while using alemtuzumab

It is very important that your doctor check your progress closely and at regular visits to make sure alemtuzumab is working properly. Blood and urine tests may be needed to check for any unwanted effects during treatment and for 48 months after your last dose. If you have signs or symptoms of an autoimmune disease, your doctor may continue to check your progress after 48 months. It is also important that your doctor check your skin for melanoma (tumor) yearly. Be sure to keep all appointments.

Do not use alemtuzumab if you are also receiving or have received Campath®.

Receiving alemtuzumab while you are pregnant can harm your unborn baby. Use an effective form of birth control to prevent from getting pregnant while you are receiving alemtuzumab and for at least 4 months after the last dose. If you think you have become pregnant while receiving alemtuzumab, tell your doctor right away.

Alemtuzumab may cause a rare but serious type of an allergic reaction called an infusion reaction. This can be life-threatening and requires immediate medical attention. Tell your doctor right away if you start to have a cough, difficulty with swallowing, dizziness, fast heartbeat, trouble breathing, chest tightness, swelling in your face or hands, fever, chills, itching or hives, or lightheadedness or faintness while you are receiving alemtuzumab.

Alemtuzumab may increase your risk of having a stroke (eg, ischemic and hemorrhagic stroke) and tears in your arteries that supply blood to your brain (carotid and vertebral arteries). Check with your doctor right away if you have parts of your face that are drooping, weakness on one side of your body, sudden, severe headache, difficulty with speech, or neck pain.

Alemtuzumab may increase your risk of cancer, including thyroid, skin, or lymph node cancer. Call your doctor right away if you have a new lump or swelling in the neck, cough, hoarseness or voice changes, neck pain, or trouble with breathing or swallowing.

Alemtuzumab may cause autoimmune disorders, including immune thrombocytopenia (ITP) or hepatitis (swelling of the liver). Tell your doctor right away if you have unusual nausea, vomiting, stomach pain, tiredness, loss of appetite, or yellow eyes or skin, dark urine, a bloody nose, coughing or spitting up blood, small red or purple spots on skin, or heavier than normal or irregular monthly periods.

Alemtuzumab may cause a serious kidney problem called anti-glomerular basement membrane disease. Call your doctor right away if you have blood in the urine, coughing up blood, or swelling in your legs or feet.

Alemtuzumab may cause hemophagocytic lymphohistiocytosis, a severe inflammatory condition that could be life-threatening, which is caused by an overactive immune system. The symptoms of this disease may occur within 13 to 33 months after starting treatment with alemtuzumab. Check with your doctor right away if you have a fever, right upper abdominal or stomach pain and fullness, rash, swollen, painful, or tender lymph glands in the neck, armpit, or groin, mental status changes, shakiness and unsteady walk, unsteadiness, trembling, or other problems with muscle control or coordination, or seizures.

Alemtuzumab may increase your risk for serious bleeding problems, including acquired hemophilia A. Check with your doctor right away if you have nosebleeds, blood in the urine or stools, or any unusual bleeding or bruising.

While you are being treated with alemtuzumab, and after you stop treatment with it, do not have any immunizations (vaccinations) without your doctor's approval. You should receive live vaccines for at least 6 weeks before starting treatment with alemtuzumab. You should not also receive alemtuzumab until 6 weeks after a varicella zoster virus (chicken pox) vaccination. Alemtuzumab may lower your body's resistance and there is a chance you might get the infection the immunization is meant to prevent. In addition, other persons living in your household should not take oral polio vaccine since there is a chance they could pass the polio virus on to you. Also, avoid persons who have taken oral polio vaccine within the last several months. Do not get close to them, and do not stay in the same room with them for very long. If you cannot take these precautions, you should consider wearing a protective face mask that covers the nose and mouth.

Alemtuzumab can temporarily lower the number of white blood cells in your blood, which will increase the risk of getting an infection. It can also lower the number of platelets, which are necessary for proper blood clotting. If this occurs, these are precautions you can take, especially when your blood count is low, to reduce the risk of infection or bleeding:

  • If you can, avoid people with infections. Check with your doctor right away if you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.
  • Check with your doctor right away if you notice any unusual bleeding or bruising, black, tarry stools, blood in the urine or stools, or pinpoint red spots on your skin.
  • Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your medical doctor before having any dental work done.
  • Do not touch your eyes or the inside of your nose unless you have just washed your hands and have not touched anything else in the meantime.
  • Be careful not to cut yourself when you are using sharp objects such as a safety razor or fingernail or toenail cutters.
  • Avoid contact sports or other situations where bruising or injury could occur.

Alemtuzumab may increase your risk of developing infections. Avoid being near people who are sick or have infections while you are receiving alemtuzumab. Wash your hands often. Tell your doctor if you have any kind of infection before you start receiving alemtuzumab. Also tell your doctor if you have ever had an infection that would not go away or an infection that kept coming back. Tell your doctor right away if you have been exposed to someone with chickenpox.

If you are a female, you should have a human papilloma virus (HPV) screening every year to avoid getting a cervical HPV infection.

You will need to have a skin test for tuberculosis (TB) before you start alemtuzumab. Tell your doctor if you or anyone in your home has ever had a positive TB skin test or been exposed to TB.

Do not eat foods that may contain a bacteria called Listeria, such as deli meat, unpasteurized milk and cheese products, or not properly cooked meat, seafood, or chicken. Make sure that the food you eat which may contain listeria is heated well when you receive alemtuzumab.

Tell your doctor right away if you have unexplained weight gain or loss, constipation, fast, pounding, or uneven heartbeat, feeling cold, swelling of the eye. These may be symptoms of a thyroid problem.

Alemtuzumab may increase your risk of developing a serious and rare brain infection called progressive multifocal leukoencephalopathy (PML). Check with your doctor if you have weakness on one side of the body, clumsiness, blurred vision, changes in thinking, memory problems, confusion, or personality changes.

Alemtuzumab can increase your risk of having gallbladder (eg, acalculous cholecystitis) and lung problems (eg, pneumonitis). Check with your doctor right away if you have stomach pain or tenderness, fever, nausea, vomiting, trouble breathing, cough, chest pain or tightness, or coughing up blood.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Alemtuzumab side effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor or nurse immediately if any of the following side effects occur:

More common

  • Black, tarry stools
  • blood in the urine
  • chills
  • cough
  • diarrhea
  • dizziness, fainting, or lightheadedness when getting up suddenly from a lying or sitting position
  • fast heartbeat
  • fever
  • headache
  • itching, hives, skin rash
  • nausea
  • painful or difficult urination
  • pale skin
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • sweating
  • swollen glands
  • tightness in the chest
  • trouble breathing
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting

Less common

  • Bloating or swelling of the face, hands, lower legs, or feet
  • chest pain
  • hoarseness
  • lower back or side pain
  • muscle weakness
  • painful cold sores or blisters on the lips, nose, eyes, or genitals
  • pounding or irregular heartbeat or pulse
  • rapid weight gain
  • red or purple spots on the skin, varying in size and remaining after pushing the skin surface
  • tremor
  • unexplained nosebleeds


  • Bloody nose
  • flushing of the face or neck
  • swelling of the eyelids, face, or lips
  • white patches on the tongue, in the mouth, or in the folds of the skin, including the genitals

Incidence not known

  • Anxiety
  • back pain
  • blindness
  • blurred or double vision
  • chest pain or discomfort
  • confusion
  • dark urine
  • decreased urine output
  • decreased vision
  • difficulty in speaking
  • dilated neck veins
  • discouragement
  • double vision
  • drowsiness
  • extreme tiredness or weakness
  • eye pain
  • feeling of discomfort
  • feeling sad or empty
  • general feeling of tiredness and weakness
  • inability to move the arms, legs, or facial muscles
  • inability to speak
  • irregular breathing
  • irritability
  • joint pain, stiffness, or swelling
  • lack of appetite
  • light-colored stools
  • loss of interest or pleasure
  • muscle aches or pain
  • nightmares or unusually vivid dreams
  • numbness, pain, tingling, or weakness
  • pain or discomfort in the arms, jaw, back, or neck
  • painful or tender lymph glands in the neck, armpit, or groin
  • seizures
  • shakiness and unsteady walk
  • slow speech
  • spitting or coughing up blood
  • sudden numbness and weakness in the arms and legs
  • swelling of the face, fingers, feet, or lower legs
  • trouble concentrating
  • trouble sleeping
  • unsteadiness, trembling, or other problems with muscle control or coordination
  • upper right abdominal or stomach pain and fullness
  • yellow eyes and skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Fear or nervousness

Less common

  • Belching
  • bone pain
  • burning, crawling, itching, numbness, prickling, “pins and needles”, or tingling feelings
  • heartburn
  • indigestion
  • lack or loss of strength
  • stomach discomfort, upset, or pain
  • swelling or inflammation of the mouth
  • weight loss


  • Constipation
  • sensation of temperature change
  • sleepiness
  • stuffy nose

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Frequently asked questions

Further information

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