Lemtrada (alemtuzumab) is an anti-CD52 monoclonal antibody. It's used to treat relapsing forms of multiple sclerosis (MS) in adults, but only when other MS medications haven't worked well. Lemtrada (alemtuzumab) is given as an infusion through the veins once per year by a healthcare provider. Since this medication has many risks and side effects, it's only available through a Risk Evaluation and Mitigation Strategy (REMS) program) called the Lemtrada REMS program. Some common side effects of Lemtrada (alemtuzumab) include rash, headache, and fever.
Relapsing forms of multiple sclerosis (MS) in adults who haven't responded well enough to at least two other MS medications
People with multiple sclerosis (MS) have an immune system that attacks their own nervous system, such as the brain and spinal cord.
Lemtrada (alemtuzumab) is a CD52 monoclonal antibody. The exact way it treats MS isn't well-understood. But it's thought to dampen the immune system by attaching to a protein called CD52 found on certain immune cells. This temporarily lowers the amount of immune cells in the body, which can lessen inflammation and bring relief of MS symptoms.
Source: DailyMed
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
dizziness, fainting, or lightheadedness when getting up suddenly from a lying or sitting position
fast heartbeat
headache
painful or difficult urination
pale skin
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
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
unexplained nosebleeds
Rare
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
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
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
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.
Works well to treat relapsing forms of MS
Treatment courses are short and are only once per year
Not many known interactions with other medications
A lot of potential risks and side effects, including serious allergic reaction, blood problems, and liver problems
Each treatment will take a least 6 hours at the clinic because of pre-treatment, infusion time, and monitoring time
Needs to be given as an IV injection by a healthcare professional
Before starting Lemtrada (alemtuzumab), check with your provider to see if you're up to date on your vaccines. You'll need to complete your vaccines at least 6 weeks before getting Lemtrada (alemtuzumab). If needed, your provider will postpone your Lemtrada (alemtuzumab) infusions.
On the day of treatment, your provider will give you IV corticosteroids right before Lemtrada (alemtuzumab) to help prevent infusion-related reactions. Please arrive early appointment so that you can receive the pre-treatment medications you need.
Each Lemtrada (alemtuzumab) infusion can take about 4 hours. You'll be monitored for at least 2 hours at the clinic after each infusion. Make sure to pack the things you need to help you stay hydrated and be more comfortable during the long stay.
Lemtrada (alemtuzumab) can raise your risk for stroke, especially within 1 to 3 days after the infusion. Call 911 if you get sudden neck or face pain, trouble speaking, droopy face, sudden confusion, or numbness or weakness in the face, arm, or leg.
Taking Lemtrada (alemtuzumab) can raise your risk for infections such as herpes. To prevent an infection, you'll need to take an antiviral medication starting the first day of each treatment course. You'll need to continue taking it for at least 2 months after Lemtrada (alemtuzumab) or until your provider says it's safe to stop taking it.
Lemtrada (alemtuzumab) can put you at risk for Listeria (a bacteria that grows in raw, undercooked, or unpasteurized foods) infection. You can protect yourself by avoiding foods like soft cheeses, raw foods, and cold cut lunch meats. Get medical help right away if your experience symptoms of Listeria such as fever, chills, diarrhea, and nausea.
Make sure to tell your provider about all the medications you're taking before starting Lemtrada (alemtuzumab), especially if you're taking medications that weaken your immune system. Don't start any new medications without talking to your provider first.
Lemtrada (alemtuzumab) can cause problems during pregnancy, including harm to unborn babies. If you're a female who's able to become pregnant, you should use birth control during the Lemtrada (alemtuzumab) treatment course and for 4 months after the treatment course is complete.
Your provider will continue to monitor your health for 4 years after your last Lemtrada (alemtuzumab) infusion. You'll likely need monthly blood and urine tests, as well as yearly skin exams. These tests are to check for possible side effects Lemtrada (alemtuzumab), including kidney problems and risk of cancer. Talk with your provider if you're not sure where to go for your check ups.
Lemtrada (alemtuzumab) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Lemtrada (alemtuzumab) is linked to many serious side effects, including autoimmune problems, infusion reactions, stroke, and cancers. Because of these risks, it's only available through a restricted Risk Evaluation and Mitigation Strategy (REMS) program called the Lemtrada REMS program. All providers who prescribe Lemtrada (alemtuzumab), pharmacies that dispense the medication, and people who need to use the injection must be registered with the REMS program. This program helps to make sure you and your providers are all aware of the risks with Lemtrada (alemtuzumab), and that you're familiar with the symptoms of serious health problems and know when it's time to get medical help.
Lemtrada (alemtuzumab) can cause your body to make antibodies. These antibodies can attack different parts of your body, which can cause serious and life-threatening problems. As a precaution, your provider will regularly monitor your labs and organ health during and for 4 years or longer after your last dose of Lemtrada (alemtuzumab).
Some specific examples of autoimmune problems seen in people taking Lemtrada (alemtuzumab) include:
Blood problems: Lemtrada (alemtuzumab) can lower your blood cell counts and raise your risk for bleeds and infections. Symptoms of blood problems include small, flat red spots under your skin, blood in urine or stool, easy bleeding or bruising, feeling tired, headache, pale skin, fast heart rate, and shortness of breath.
Kidney problems: Lemtrada (alemtuzumab) can cause kidney problems. Symptoms include swelling, changes in urine color, urinating less, trouble breathing, coughing up blood, nausea, vomiting, and weakness.
Thyroid problems: Lemtrada (alemtuzumab) can cause either too much or too little thyroid hormone, and other thyroid problems. Symptoms include changes in eating habits, changes in ability to tolerate cold or heat, and changes in weight.
Liver problems: Lemtrada (alemtuzumab) can cause liver problems. Symptoms include nausea, vomiting, stomach pain, low appetite, dark urine, and yellowing of the skin or whites of the eyes.
Contact your provider immediately if you notice any of these symptoms.
It's possible for you to get severe allergic and infusion reactions with Lemtrada (alemtuzumab). These reactions typically happen within 3 days of your infusion. To lower your risk for these reactions, your provider will have you take corticosteroids for the first 3 days of each treatment course. Your provider will also monitor you for at least 2 hours after the Lemtrada (alemtuzumab) infusion to make sure you're not experiencing any symptoms. If you do experience symptoms of an allergic or infusion-related reaction such as swelling in the mouth or throat, trouble breathing, weakness, rash, or chest pain, get medical help right away.
Lemtrada (alemtuzumab) can raise your risk of getting a stroke. This is most likely to happen within 3 days of receiving Lemtrada (alemtuzumab). Call 911 if you experience symptoms of stroke, such as sudden neck or face pain, trouble speaking, droopy face, sudden confusion, or numbness or weakness in the face, arm, or leg.
Risk factors: History of cancer
Lemtrada (alemtuzumab) can raise your risk of certain cancers, such as thyroid cancer and skin cancer. Contact your provider if you notice signs of thyroid cancer, such as any new lumps or swelling in your neck, pain in the front of the neck, changes in your voice, trouble swallowing or breathing, constant cough not due to an infection, or changes in your skin.
Make sure you also schedule yearly screenings for skin cancer and let your provider know if you notice changes to your skin.
Lemtrada (alemtuzumab) can cause several types of inflammatory problems. Specific examples of inflammatory problems seen in people taking Lemtrada (alemtuzumab) include:
Overactive immune system: Lemtrada (alemtuzumab) can cause your immune system to become overly active. This is rare, but potentially deadly and side effects can appear 1 to 3 years after treatment. Get medical help right away if you notice symptoms including fever, swollen lymph nodes, changes in your mood or ability to think, seizures, and difficulty maintaining balance.
Inflammation of the entire body: Lemtrada (alemtuzumab) can cause your whole body to become inflamed. Let your provider know if you experience symptoms such as joint pain, muscle pain, rash, high fever, and sore throat.
Inflammation of the gallbladder: Lemtrada (alemtuzumab) can cause inflammation in your gallbladder. Tell your provider if you feel stomach pain, have a fever, and experience nausea or vomiting.
Inflammation of the lungs: Lemtrada (alemtuzumab) can cause your lungs to become inflamed. Get medical attention if you experience shortness of breath, cough, wheezing, chest pain or tightness, or start to vomit blood.
Contact your provider right away if you notice any of these symptoms.
Risk factors: Active, chronic, or recurrent infection | Having other conditions that raise your risk of infection | Living in or traveling to places with high rates of TB infections | Taking medications that weaken your immune system
Lemtrada (alemtuzumab) can affect your body's ability to fight off infections, which can raise your risk of serious bacterial (e.g., Listeria, tuberculosis (TB)), viral (e.g., herpes, hepatitis, human papilloma virus (HPV)), or fungal infections. Your provider will routinely monitor you for infections before and during treatment with Lemtrada (alemtuzumab) and might give you antimicrobial medications to prevent or treat the infection(s).
To lower your risk for Listeria (a bacteria that grows in raw, undercooked, or unpasteurized foods) infection, make sure to review which types of foods can potentially have Listeria. If you get an infection, you might have to stop taking Lemtrada (alemtuzumab) so your body can fight it off. Get medical help right away if you have fever, cough, difficulty breathing, diarrhea, weakness, sweating, or chills while taking Lemtrada (alemtuzumab).
A full treatment with Lemtrada (alemtuzumab) includes 2 treatment courses, given a year apart.
First treatment course: The typical dose is 12 mg infused into the veins (IV) once daily for 5 days by a healthcare provider.
Second treatment course: The second treatment course is given 1 year after the first treatment course. The typical dose is 12 mg infused IV once daily for 3 days by a healthcare provider.
If needed, your provider might have you continue with additional treatment courses of Lemtrada (alemtuzumab). Each additional course can be given 1 year after your last course. The typical dose is 12 mg infused IV once daily for 3 days.
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 this medicine, 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 this medicine 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.
Using this medicine 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.
Active infection
Relapsing forms of multiple sclerosis (MS) in adults who haven't responded well enough to at least two other MS medications
Relapsing forms of multiple sclerosis (MS)
Moderate-to-severe Crohn's disease (CD) when other treatments haven't worked well
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American Cancer Society. (2019). What is thyroid cancer?
Centers for Disease Control and Prevention. (n.d.). Fungal diseases.
Centers for Disease Control and Prevention. (2023). Prevent Listeria.
Coles, A. J., et al. (2012). Alemtuzumab for patients with relapsing multiple sclerosis after disease-modifying therapy: A randomised controlled phase 3 trial. Lancet.
Genzyme Corporation. (n.d.). During treatment.
Genzyme Corporation. (2022). Your guide to treatment: Step-by-step.
Genzyme Corporation. (2023). Campath- alemtuzumab injection [package insert]. DailyMed.
Genzyme Corporation. (2023). Lemtrada- alemtuzumab injection, solution, concentrate [package insert]. DailyMed.
Janssen, B., et al. (2021). What is hypersensitivity pneumonitis? American Journal of Respiratory and Critical Care Medicine.
Jones, M. W., et al. (2023). Acalculous cholecystitis. StatPearls.
National Organization for Rare Disorders. (2018). Hemophagocytic lymphohistiocytosis.
National Organization for Rare Disorders. (2021). Adult-onset Still’s disease.
Whitley, R. J., et al. (1996). Chapter 68: Herpesviruses. Medical Microbiology, 4th edition.
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