Alemtuzumab
Alemtuzumab is a monoclonal antibody that targets CD52, an antigen found on the surface of immune cells including B and T lymphocytes. It is used to treat certain autoimmune and hematological conditions by depleting these immune cells through antibody-mediated mechanisms. The medication is administered as an intravenous infusion under specialized supervision due to its significant immunosuppressive effects.
Alemtuzumab is an immunosuppressant monoclonal antibody that targets CD52 on immune cells to treat multiple sclerosis and certain leukemias.
This medication carries a boxed (black box) warning — the strongest type of FDA warning. Review the full prescribing information before use.
Key facts at a glance
- ATC
- L04AG06
- RxNorm
- 117055
- Generic
- Alemtuzumab
- Class
- atc-l04
- Brands
- Lemtrada, Campath
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- injection
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 500mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 250mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 400mg daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
9 groupspregnancy
first trimesteravoid if possible
avoid use during pregnancy unless benefits outweigh risks; women of childbearing potential should use effective contraception during and for 4 months after treatment
regular fetal monitoring including ultrasound assessments
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
second and third trimesteravoid if possible
discontinue treatment if pregnancy occurs; continue to avoid use unless critical
regular fetal monitoring, ultrasound for fetal growth
Use of this medication in this population requires careful consideration of risks and benefits.
lactation
breastfeedingavoid
discontinue breastfeeding during treatment and for at least 4 months after last infusion
not applicable
Use of this medication in this population requires careful consideration of risks and benefits.
pediatric_age
adolescents 12 to 17use with caution, not recommended as first-line therapy
safety and efficacy established in pediatric MS patients 10 years and older; closer monitoring required for infections and immune reactions
regular monitoring of complete blood count, liver enzymes, thyroid function; close surveillance for infections
Use with caution and monitor for adverse effects.
geriatric
elderly 65 and olderno specific dose adjustment required but use with caution
use with caution due to limited clinical experience; assess cardiovascular status before treatment
monitor cardiac function, renal function, and for signs of infection more frequently
Use with caution and monitor for adverse effects.
renal_impairment
mild to moderateno specific dose adjustment needed
monitor renal function before and during treatment; caution in patients with pre-existing renal disease
regular serum creatinine and eGFR monitoring
Use with caution and monitor for adverse effects.
renal_impairment
severeuse with caution
limited data in severe renal impairment; careful risk-benefit assessment required
intensive renal function monitoring
Use with caution and monitor for adverse effects.
hepatic_impairment
mild to moderateno specific dose adjustment required
limited data available; monitor liver function tests
regular liver function test monitoring
Use with caution and monitor for adverse effects.
hepatic_impairment
severeuse with extreme caution
not studied in severe hepatic impairment; careful risk-benefit assessment required
frequent liver function monitoring
Statistics and clinical data
FDA approval for MS
FDA approved alemtuzumab (Lemtrada) for treatment of relapsing forms of multiple sclerosis in May 2014
Drug class
Alemtuzumab is a humanized IgG1 monoclonal antibody targeting CD52 antigen
Primary indication
Used for treatment of active disease not responding to two or more other MS therapies
Mechanism of action
Binds to CD52 on lymphocytes causing their depletion and subsequent immune system reconstitution
Alemtuzumab is primarily used to treat relapsing forms of multiple sclerosis (MS) in adults and chronic lymphocytic leukemia (CLL), particularly in patients who have not responded to standard therapies.
Alemtuzumab binds to the CD52 antigen present on the surface of B and T lymphocytes, monocytes, macrophages, NK cells, and some granulocytes. This binding triggers antibody-dependent cellular cytotoxicity, leading to the depletion of these immune cells. The exact therapeutic mechanism in MS involves depletion and repopulation of lymphocytes with potential modulation of immune pathways involved in autoimmunity.
Due to significant immunosuppression, patients are at increased risk for infections and infusion reactions. Autoimmune conditions, particularly thyroid disorders and immune thrombocytopenia, may occur. Regular monitoring for blood counts, thyroid function, and signs of infection is required. Vaccination should be completed before treatment initiation. The medication is only available through restricted programs and must be administered by healthcare professionals experienced in its use.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy