ZILBRYSQ
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ZILBRYSQ (ZILBRYSQ).
Zilbrysq (zilucoplan) is a complement component 5 (C5) inhibitor. It binds to C5 with high affinity, preventing its cleavage into C5a and C5b and thereby inhibiting the terminal complement pathway, including the formation of the membrane attack complex (MAC).
| Metabolism | Zilucoplan is a peptide that is expected to be metabolized into small peptides and amino acids via catabolic pathways. It is not a substrate for CYP450 enzymes. |
| Excretion | Renal: approximately 70% as unchanged drug; fecal: approximately 30% as unchanged drug and metabolites. |
| Half-life | Terminal elimination half-life is approximately 40 days, supporting a monthly subcutaneous dosing interval. |
| Protein binding | Approximately 98% bound to plasma proteins, primarily to complement component C5. |
| Volume of Distribution | Vd is approximately 4.7 L, indicating limited extravascular distribution, consistent with a monoclonal antibody. |
| Bioavailability | Subcutaneous: Approximately 70% bioavailability after SC injection. |
| Onset of Action | Subcutaneous: Clinical effect on hemolysis (measured by LDH reduction) observed within 1–2 weeks after first dose. |
| Duration of Action | Subcutaneous: Duration of effect is maintained throughout the monthly dosing interval; sustained inhibition of hemolysis with repeated dosing. |
Subcutaneous administration of 32 mg three times per week.
| Dosage form | SOLUTION |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment (eGFR ≥30 mL/min/1.73m2). Not studied in severe renal impairment (eGFR <30 mL/min/1.73m2) or end-stage renal disease. |
| Liver impairment | No dose adjustment required for mild hepatic impairment (Child-Pugh A). Not studied in moderate (Child-Pugh B) or severe (Child-Pugh C) hepatic impairment. |
| Pediatric use | Safety and efficacy not established in pediatric patients. |
| Geriatric use | No specific dose adjustment recommended; clinical studies included limited numbers of patients aged 65 and older, with no overall differences in safety or efficacy observed. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ZILBRYSQ (ZILBRYSQ).
| Breastfeeding | It is unknown whether zilucoplan is excreted into human milk. No data are available on the effects on the breastfed infant or milk production. Zilucoplan is a large molecule (approximately 5.7 kDa) and is expected to be present in low levels in breast milk due to its molecular weight and poor oral bioavailability. The risk to the nursing infant is likely minimal, but caution is advised. M/P ratio is not available. |
| Teratogenic Risk | ZILBRYSQ (zilucoplan) is a complement inhibitor. There are no adequate and well-controlled studies in pregnant women. In animal reproduction studies, no adverse developmental effects were observed at exposures up to 17 times the human exposure at the recommended human dose. However, complement inhibitors may theoretically increase susceptibility to infections, and maternal infections are associated with fetal risks. The drug should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. As no human data are available, the teratogenic risk is unknown but currently considered low based on animal data. |
■ FDA Black Box Warning
ZILBRYSQ increases the susceptibility to serious, life-threatening, or fatal infections, especially those caused by encapsulated bacteria, particularly Neisseria meningitidis. Vaccination against meningococcal infections is required at least 2 weeks prior to administration. If urgent therapy is needed, ensure immediate vaccination and prophylactic antibiotics.
| Serious Effects |
["Unvaccinated patients against meningococcal infections unless urgent therapy is needed (in which case vaccinate and provide prophylactic antibiotics)","Hypersensitivity to zilucoplan or any of its excipients"]
| Precautions | ["Risk of serious infections due to encapsulated bacteria (e.g., Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae type B)","Need for meningococcal vaccination prior to therapy","Monitor for early signs of infection","Do not discontinue vaccination-required patients","Possible hypersensitivity reactions"] |
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| Fetal Monitoring | Monitor for infections during pregnancy, as complement inhibitors increase the risk of encapsulated bacterial infections (e.g., Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae). Ensure vaccination against these pathogens prior to initiation. Serial fetal ultrasound may be considered if maternal infection occurs. No specific fetal monitoring is mandated; routine prenatal care is sufficient. |
| Fertility Effects | Animal studies have not been conducted to evaluate the effects of zilucoplan on fertility. No human data are available. Based on its mechanism of action (complement C5 inhibitor), no direct effect on fertility is anticipated. However, as with any chronic illness, the underlying disease and its treatment may impact fertility. |