Section 04 · Monograph

Eculizumab

Reviewed Nov 2026FDA label

SolirisComplement C5 inhibitor

Black Box Warning

Life-threatening and fatal meningococcal infections (Neisseria meningitidis septicemia and/or meningitis) have occurred in patients treated with Soliris
Complete or update meningococcal vaccination at least 2 weeks prior to the first dose of Soliris unless the risks of delaying therapy outweigh the risk of developing a meningococcal infection
Patients vaccinated less than 2 weeks before starting Soliris, or unvaccinated, must receive prophylactic antibiotics until 2 weeks after vaccination
Vaccination reduces but does not eliminate the risk of meningococcal infection; monitor patients for early signs of meningococcal infection and evaluate immediately if infection is suspected
Soliris is available only through a restricted program called the Ultomiris and Soliris REMS, which requires prescriber, pharmacy, and patient enrollment

Paroxysmal nocturnal hemoglobinuria (PNH), to reduce hemolysisFDA-labeled
Atypical hemolytic uremic syndrome (aHUS), to inhibit complement-mediated thrombotic microangiopathyFDA-labeled
Generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) antibody positiveFDA-labeled
Neuromyelitis optica spectrum disorder (NMOSD) in adult patients who are anti-aquaporin-4 (AQP4) antibody positiveFDA-labeled

Humanized IgG2/4 kappa monoclonal antibody that binds with high affinity to the complement protein C5
Inhibits cleavage of C5 into C5a and C5b, preventing generation of the terminal complement complex C5b-9 (membrane attack complex)
In NMOSD, the mechanism is presumed to involve inhibition of AQP4-antibody-induced, complement-dependent astrocyte injury via blockade of terminal complement C5b-9 deposition
Terminal complement blockade impairs host defense against encapsulated organisms, particularly Neisseria meningitidis, which is the basis for the boxed warning

NMOSD induction: 900 mg IV weekly for the first 4 weeks
NMOSD induction, 5th dose: 1200 mg IV administered 1 week after the fourth weekly dose
NMOSD maintenance: 1200 mg IV every 2 weeks thereafter
Administer by intravenous infusion over 35 minutes (via gravity feed, syringe-type pump, or infusion pump)
PNH, aHUS, and gMG follow separate weight-/indication-specific induction and maintenance regimens per full prescribing information
Supplemental dosing is required after plasmapheresis, plasma exchange, or fresh frozen plasma infusion because these procedures markedly increase eculizumab clearance

Contraindicated for initiation in patients with unresolved serious Neisseria meningitidis infection
Contraindicated in patients not currently vaccinated against Neisseria meningitidis, unless the risks of delaying treatment outweigh the risk of developing a meningococcal infection

Neonatal Fc receptor (FcRn) blocker therapies (e.g., efgartigimod) may lower systemic eculizumab exposure and reduce effectiveness
Plasmapheresis, plasma exchange, or fresh frozen plasma infusion increases eculizumab clearance (up to ~6-fold with plasma exchange) and requires supplemental dosing per label
No cytochrome P450-mediated drug-drug interactions expected; eculizumab is a monoclonal antibody not metabolized via hepatic CYP pathways

Confirm meningococcal vaccination status before initiation; if therapy cannot be delayed 2 weeks for vaccination, provide antibiotic prophylaxis
Monitor closely for early signs/symptoms of meningococcal infection (fever, headache, neck stiffness, photophobia, altered mental status) and treat immediately if suspected
Enrollment in the Soliris REMS program is required for prescribers, pharmacies, and patients
Additional vaccination against other encapsulated organisms (S. pneumoniae, H. influenzae) is recommended per ACIP guidelines
Monitor for infusion-related reactions during administration
Monitor for disease manifestations (rebound hemolysis/thrombotic microangiopathy, NMOSD relapse) if therapy is interrupted or discontinued

Available pregnancy data from case reports/series have not identified a drug-associated risk of major birth defects or miscarriage, though data are limited
Animal reproduction studies using a homologous antibody in mice showed increased developmental abnormalities at doses 2-8 times the human dose
A pregnancy exposure registry exists for women exposed to Soliris during pregnancy
Maternal IgG is known to be present in breast milk; there are no data on eculizumab in human milk, its effects on the breastfed infant, or on milk production — weigh developmental/health benefits of breastfeeding against the mother's clinical need for therapy