Eculizumab
Eculizumab is a monoclonal antibody that targets the complement protein C5 to prevent complement-mediated cell damage. It is used to treat rare disorders caused by abnormal complement activation, including paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS), generalized myasthenia gravis, and neuromyelitis optica spectrum disorder.
A complement inhibitor monoclonal antibody used for rare disorders caused by excessive complement activity.
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
- L04AJ01
- RxNorm
- 591781
- Generic
- Eculizumab
- Class
- atc-l04
- Brands
- Epysqli, Bkemv, Soliris
- 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
- 600mg weekly for 4 weeks, then 900mg every 2 weeks
- Maximum
- consult physician
- Frequency
- initial weekly, then every 2 weeks
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- Weight-based dosing: 900mg weekly for 4 weeks, then 1200mg every 2 weeks for ≥40kg
- Maximum
- consult physician
- Frequency
- initial weekly, then every 2 weeks
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 600mg weekly for 4 weeks, then 900mg every 2 weeks
- Maximum
- consult physician
- Frequency
- initial weekly, then every 2 weeks
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
8 groupspregnancy
first trimesteravoid if possible
use only if benefits outweigh potential risks to fetus
regular fetal monitoring and ultrasound assessments
Use with caution and monitor for adverse effects.
pregnancy
second third trimestercontinue if already receiving
continue treatment if already pregnant and benefiting from therapy
close fetal monitoring throughout pregnancy
Use with caution and monitor for adverse effects.
lactation
breastfeedingno adjustment
discontinue breastfeeding or discontinue drug considering risk to infant
monitor infant for signs of infection
pediatric_age
children under 18weight-based dosing required
approved for aHUS in pediatric patients; not established for PNH in patients under 18
monitor for infections and hematological parameters
Use with caution and monitor for adverse effects.
geriatric
elderly 65 plusno specific adjustment
use with caution due to limited clinical trial data in elderly population
regular monitoring of renal function and infection symptoms
Use with caution and monitor for adverse effects.
renal_impairment
all stagesno dose adjustment
no dose adjustment needed for any degree of renal impairment
routine monitoring of renal function
hepatic_impairment
mild to moderateno specific adjustment
use with caution due to limited study data in hepatic impairment
monitor liver function tests
Use with caution and monitor for adverse effects.
alcohol_users
chronic alcohol useno specific adjustment
use with caution; consider vaccination status for infections
monitor for increased infection risk
Use with caution and monitor for adverse effects.
Statistics and clinical data
First FDA approval year
Initial FDA approval for paroxysmal nocturnal hemoglobinuria
Drug class
Therapeutic classification as complement-inhibiting monoclonal antibody
Primary indications
Approved therapeutic indications
Mechanism of action
Pharmacological mechanism of action
Treats paroxysmal nocturnal hemoglobinuria (PNH) to reduce hemolysis, atypical hemolytic uremic syndrome (aHUS) to prevent thrombotic microangiopathy, generalized myasthenia gravis in anti-AChR positive patients, and neuromyelitis optica spectrum disorder (NMOSD) in anti-aquaporin-4 positive patients.
Binds with high affinity to complement protein C5, preventing its cleavage into C5a (inflammatory mediator) and C5b (which initiates the terminal complement complex C5b-9 that causes cell destruction). This blocks complement-mediated damage to cells.
Carries a black box warning for serious meningococcal infection risk; patients must receive meningococcal vaccinations before initiation. Available only through a restricted REMS program. Increases susceptibility to infections; monitor for signs of infection during treatment.
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