PeptideTrace
ApprovedComplement C5 Inhibitor (Peptide)Immune & Anti-inflammatory

Zilucoplan (Zilbrysq)

A

Evidence Grade A — Regulatory approved. 83 published studies. 19 registered clinical trials.

19 trials83 studiesUSEUCA

Medically reviewed by a licensed medical professional

Licensed Indications

  • Generalized Myasthenia Gravis

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Overview

Zilucoplan (sold as Zilbrysq) is a self-injectable treatment for generalised myasthenia gravis — a condition where the immune system attacks the connections between nerves and muscles, causing fluctuating weakness that can affect breathing, swallowing, and movement. Its key advantage over existing treatments is that patients can inject it themselves at home daily, rather than needing hospital visits for intravenous infusions.

Also Known As

Zilucoplan is also known by these brand and alternate names:

Research Activity

83studies
Human 52
In-vitro 4
Reviews 31

83 published studies: 52 human, 0 animal, 4 in-vitro, 31 reviews

Regulatory Status

US
FDA-approved(FDA)
EU
EMA-authorised(EMA)
CA
Health Canada approved(Health Canada)

Legal Status

USPrescription drug (Rx)
EUPrescription medicine (EU centralised authorisation)
CAPrescription drug

Summary

Zilucoplan is marketed as Zilbrysq (approved October 2023) for anti-acetylcholine receptor antibody-positive generalised myasthenia gravis in adults. Administered as a daily subcutaneous self-injection.

In the RAISE trial, zilucoplan showed statistically significant improvements in both activities of daily living and quantitative muscle strength scores compared to placebo, with improvements evident from week one. Its key differentiator from existing complement inhibitors (eculizumab, ravulizumab) is the self-injectable format — those alternatives require hospital-based intravenous infusions. As with all complement inhibitors, patients require meningococcal vaccination before starting treatment due to increased susceptibility to meningococcal infection.

Mechanism of Action

In antibody-positive myasthenia gravis, immune antibodies against the acetylcholine receptor activate the complement system — a destructive cascade of immune proteins. The final step of this cascade creates a 'membrane attack complex' (MAC) that punches holes in the muscle cell membrane at the neuromuscular junction, destroying the receptor-rich folds that receive nerve signals. Zilucoplan blocks complement component C5, preventing both the formation of the MAC and the release of the inflammatory signal C5a, halting the destruction.

Research Summary

The RAISE trial showed statistically significant improvements in both daily activities and muscle strength scores compared to placebo, with benefits appearing within the first week. As a small synthetic peptide (approximately 40 times smaller than the antibody-based complement inhibitors eculizumab and ravulizumab), zilucoplan can be delivered as a subcutaneous injection rather than requiring IV infusions. As with all complement inhibitors, patients must be vaccinated against meningococcal bacteria at least two weeks before starting treatment, because the drug reduces the immune system's ability to fight these infections. Data are currently limited to 12 weeks, with no head-to-head comparisons against existing treatments (eculizumab, ravulizumab, or efgartigimod). The self-administration convenience is the primary differentiator in a field where existing treatments work well but require hospital-based infusions.

Clinical Trials

PeptideTrace tracks 19 registered clinical trials for Zilucoplan sourced from ClinicalTrials.gov.

NCT07215949Phase IIIRecruiting

Zilucoplan for Severe gMG Exacerbations

Miriam FreimerEndpoint: Change from baseline to Week 2 in the Myasthenia Gravis - Activities of Daily Living (MG-ADL) scoreCompletion: 2028-04-01
NCT06961747Phase IRecruiting

A Study to Assess Zilucoplan Concentration in Breast Milk of Healthy Lactating Women

UCB Biopharma SRLEndpoint: Concentrations of zilucoplan and its major metabolites (RA103488 and RA102758) in breast milk during 24 hour steady state (SS) Sampling PeriodCompletion: 2027-03-23
NCT06815133N/ARecruiting

Effectiveness and Safety of Zilucoplan Treatment for French Patients With Myasthenia Gravis Over 3 Months

Centre Hospitalier Universitaire de NiceEndpoint: MG-ADL scoresCompletion: 2026-03-03
NCT06435312Phase IIIEnrolling by Invitation

An Open-label Extension Study to Evaluate Subcutaneous Zilucoplan in Pediatric Participants With Generalized Myasthenia Gravis

UCB Biopharma SRLEndpoint: Occurence of treatment emergent adverse events during the course of the studyCompletion: 2027-11-19
NCT06055959Phase IIIRecruiting

A Study to Evaluate Subcutaneous Zilucoplan in Pediatric Participants With Generalized Myasthenia Gravis

UCB Biopharma SRLEndpoint: Plasma concentrations of zilucoplan (ZLP) sampled at Week 4 (Day 29)Completion: 2026-12-25
View all 19 trials on ClinicalTrials.gov →

Regulatory Timeline

2023
Regulatory

FDA ORIG 1

2023
Regulatory

EMA Marketing Authorisation

2024
Regulatory

FDA SUPPL 4

2024
Regulatory

FDA SUPPL 1

2025
Regulatory

FDA SUPPL 9

2025
Regulatory

FDA SUPPL 8

2025
Regulatory

Health Canada Market Authorisation

2026
Regulatory

FDA SUPPL 13

Scientific Detail

Overview (Scientific)

Zilucoplan is a macrocyclic peptide C5 inhibitor, 15 amino acids (synthetic), MW ~3,500 Da. Incorporates non-natural amino acids and PEG linker. Identified via mRNA display (>10^12 variants). Binds distinct C5 epitope vs. eculizumab. Small size (~3.5 kDa vs. ~148 kDa) enables SC self-administration. SC 0.3 mg/kg daily. Half-life ~25.5 hours.

Mechanism of Action (Scientific)

Binds complement C5 (~0.5 nM Kd), preventing cleavage by C5 convertases into C5a (anaphylatoxin) and C5b (initiates MAC). In MG, anti-AChR antibodies activate classical complement at neuromuscular junction, causing MAC destruction of postsynaptic folds. Zilucoplan prevents both C5a inflammation and MAC formation.

Summary (Scientific)

Marketed as Zilbrysq. Approved October 17, 2023. RAISE (Phase III; N=174): MG-ADL improvement -3.37 vs. -2.30 (difference -1.07, P=0.0260). QMG: -4.39 vs. -2.30 (P=0.0052). Response from Week 1. Indication: anti-AChR antibody-positive gMG in adults.

Related Compounds

Vancomycin

Approved
Glycopeptide Antibiotic

Vancomycin is marketed as Vancocin and Firvanq (approved 1958, with oral solution Firvanq approved 2018). It is the standard treatment for serious MRSA infections (bloodstream infections, endocarditis, pneumonia, bone infections) and is first-line for severe C. difficile colitis. Vancomycin requires therapeutic drug monitoring — blood levels must be checked regularly to ensure the dose is effective without causing kidney damage or hearing loss. The rise of vancomycin-resistant enterococci (VRE) and occasional vancomycin-intermediate S. aureus (VISA) strains represent ongoing challenges. Despite being nearly 70 years old, vancomycin remains irreplaceable for many serious infections, though newer alternatives like daptomycin and the lipoglycopeptides offer advantages in specific settings.

Daptomycin

Approved
Lipopeptide Antibiotic

Daptomycin is marketed as Cubicin (approved September 2003). It is indicated for complicated skin and soft tissue infections and S. aureus bloodstream infections including right-sided endocarditis. Administered as a once-daily intravenous infusion. A key limitation is that daptomycin cannot be used for pneumonia — lung surfactant inactivates the drug. In the bacteraemia trial, daptomycin was non-inferior to vancomycin with significantly lower rates of kidney problems (11% versus 26%). Creatine kinase (CK) levels must be monitored during treatment, as daptomycin can cause muscle toxicity. Generics became available after patent expiry, significantly reducing cost.

Bacitracin

Approved
Polypeptide Antibiotic (Topical)

Bacitracin is marketed as Baciguent (topical) and BACiiM (injection), and is a component of Neosporin and Polysporin. Approved in 1948, it is one of the oldest peptide antibiotics still in widespread use. Topical bacitracin is available over the counter and is applied to minor cuts, scrapes, and burns to prevent infection. Its systemic use is limited to rare situations where no alternatives exist, due to severe nephrotoxicity. There has been growing discussion in wound care about whether routine topical antibiotic use on minor wounds provides meaningful benefit over simple petroleum jelly in keeping wounds moist, and about the risk of contact allergic dermatitis with repeated bacitracin use.

Related Research

This content is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before making decisions about your health.