Ofatumumab
Ofatumumab is a monoclonal antibody that targets and depletes CD20-positive B lymphocytes, which are believed to play a role in the inflammatory processes underlying multiple sclerosis. It is used as a disease-modifying therapy for patients with certain forms of relapsing multiple sclerosis, administered via subcutaneous injection typically at home after initial dosing.
Ofatumumab is a B-cell depleting monoclonal antibody used to treat multiple sclerosis by targeting CD20 on B lymphocytes.
Key facts at a glance
- ATC
- L01FA02
- RxNorm
- 712566
- Generic
- Ofatumumab
- Class
- atc-l01
- Brands
- Kesimpta, Arzerra
- 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
7 groupspregnancy
first trimesteravoid if possible
avoid use during pregnancy unless benefits outweigh risks; women of reproductive potential should use effective contraception during treatment and for at least 6 months after last dose
regular fetal monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
third trimesteravoid if possible
avoid use in third trimester due to potential risk of B-cell depletion in neonates; consider delaying treatment if possible
monitor neonatal B-cell counts after birth
Use of this medication in this population requires careful consideration of risks and benefits.
lactation
breastfeedingdiscontinue breastfeeding
do not breastfeed during treatment and for at least 6 months after the last dose of ofatumumab
monitor infant for signs of infection or immunosuppression
Use of this medication in this population requires careful consideration of risks and benefits.
geriatric
elderly 65no dose adjustment required
use with caution; monitor for increased susceptibility to infections
regular monitoring of blood counts and for signs of infection
Use with caution and monitor for adverse effects.
pediatric_age
children adolescentsnot established
not recommended for use in pediatric patients; safety and efficacy not established
not applicable
renal_impairment
moderate to severeno dose adjustment expected
no dose adjustment required for patients with renal impairment; however, monitor renal function regularly
monitor renal function tests periodically
Use with caution and monitor for adverse effects.
hepatic_impairment
mild to moderateno dose adjustment expected
no dose adjustment required for patients with mild to moderate hepatic impairment; limited data in severe hepatic impairment
monitor liver function tests periodically
Use with caution and monitor for adverse effects.
Statistics and clinical data
Drug class
Biologic classification based on mechanism of action
Primary indication (Kesimpta)
FDA-approved therapeutic indication
Primary indication (Arzerra)
FDA-approved therapeutic indication
Mechanism of action
Pharmacological mechanism of action
Ofatumumab is indicated for the treatment of relapsing forms of multiple sclerosis (RMS), including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease in adults.
Ofatumumab binds to the CD20 antigen on the surface of pre-B and mature B lymphocytes, leading to B-cell depletion through immune mechanisms including complement-dependent cytotoxicity and antibody-dependent cellular cytotoxicity, thereby reducing the inflammatory response that damages nerves in MS.
Ofatumumab is administered subcutaneously and requires monitoring for infections during treatment due to its immunosuppressive effects. Patients should be screened for hepatitis B before starting therapy and may need to complete required vaccinations prior to treatment initiation.
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