Zilucoplan — Complete Research Guide (2026)

Last updated 2026-06-30

What is Zilucoplan?

Zilucoplan (brand name Zilbrysq) is a synthetic macrocyclic peptide that inhibits complement component 5 (C5). The US FDA approved it in October 2023 for generalized myasthenia gravis (gMG) in adults who are anti-acetylcholine receptor (anti-AChR) antibody positive.

The evidence is pivotal-trial grade: approval was based on the randomized, double-blind, placebo-controlled phase 3 RAISE trial, supported by a phase 2 study and an ongoing open-label extension, all in humans.

How does Zilucoplan work?

Zilucoplan binds complement component 5 (C5) and blocks its cleavage into C5a and C5b, preventing formation of the terminal membrane attack complex and thereby reducing complement-mediated damage at the neuromuscular junction.

Biochemical work indicates it uses a dual mode of action to prevent terminal complement activation.

What does the research say about Zilucoplan?

• In the pivotal phase 3 RAISE trial, zilucoplan significantly reduced the Myasthenia Gravis Activities of Daily Living (MG-ADL) score versus placebo at week 12 in anti-AChR-antibody-positive adults with generalized MG. ^[1]
• A randomized phase 2 study first demonstrated that self-administered subcutaneous zilucoplan produced clinically meaningful, dose-dependent improvements in patients with moderate-to-severe generalized MG. ^[2]
• In an open-label extension (RAISE-XT) interim analysis, benefits observed in the controlled trial were sustained with longer-term treatment and the safety profile remained consistent. ^[3]

Clinical research & studies

The references below are the primary sources cited throughout this guide. Each links directly to PubMed or the regulator. Where evidence is preclinical (animal or in-vitro), that is stated rather than implied.

• [1] Safety and efficacy of zilucoplan in patients with generalised myasthenia gravis (RAISE): a randomised, double-blind, placebo-controlled, phase 3 study — Howard JF Jr et al., Lancet Neurology 2023. (Randomized double-blind placebo-controlled phase 3 trial (RAISE))
• [2] Clinical Effects of the Self-administered Subcutaneous Complement Inhibitor Zilucoplan in Patients With Moderate to Severe Generalized Myasthenia Gravis: A Randomized Clinical Trial — Howard JF Jr et al., JAMA Neurology 2020. (Randomized double-blind placebo-controlled phase 2 trial)
• [3] Long-term safety and efficacy of zilucoplan in patients with generalized myasthenia gravis: interim analysis of the RAISE-XT open-label extension study — Howard JF Jr et al., Therapeutic Advances in Neurological Disorders 2024. (Open-label extension study (interim analysis))
• [4] Zilucoplan, a macrocyclic peptide inhibitor of human complement component 5, uses a dual mode of action to prevent terminal complement activation — Tang GQ et al., Frontiers in Immunology 2023. (Preclinical/biochemical mechanistic study)
• [5] Zilucoplan: First Approval — Shirley M et al., Drugs 2024. (Drug-approval review)
• [6] Efficacy of zilucoplan in patients with generalised myasthenia gravis who have not previously received immunosuppressive/immunomodulatory therapy — Utsugisawa K et al., Journal of the Neurological Sciences 2025. (Post-hoc subgroup analysis of trial data)

Dosing context

Zilucoplan is a once-daily subcutaneous injection that patients can self-administer at home after training, with dose based on body weight.

This is background context only, not a dosing instruction; the actual regimen, vaccination requirements, and monitoring must be directed by the prescribing physician per the approved label.

Side effects & safety profile

Because zilucoplan inhibits terminal complement, it increases the risk of serious infections caused by encapsulated bacteria, especially Neisseria meningitidis; meningococcal vaccination is required before starting treatment (with additional antibiotic prophylaxis if therapy must begin urgently), and patients must be monitored for early signs of meningococcal infection.

It is given as a once-daily self-administered subcutaneous injection, so injection-site reactions can occur.

Other reported adverse effects include upper respiratory and other infections; it should be prescribed and monitored by a clinician experienced in managing myasthenia gravis and complement inhibition.

Stacking & combinations

It should not be casually combined with other complement inhibitors or unapproved compounds, because layered complement blockade further raises serious infection risk and any combination therapy must be physician-directed.

Finding Zilucoplan vendors

User reviews

Frequently asked questions

References

1. [1] Safety and efficacy of zilucoplan in patients with generalised myasthenia gravis (RAISE): a randomised, double-blind, placebo-controlled, phase 3 study — Howard JF Jr et al., Lancet Neurology 2023. PMID: 37059508. View sourceStudy: Randomized double-blind placebo-controlled phase 3 trial (RAISE)Zilucoplan significantly reduced MG-ADL and other MG severity scores versus placebo at week 12 in anti-AChR-antibody-positive generalized MG, with a manageable safety profile.
2. [2] Clinical Effects of the Self-administered Subcutaneous Complement Inhibitor Zilucoplan in Patients With Moderate to Severe Generalized Myasthenia Gravis: A Randomized Clinical Trial — Howard JF Jr et al., JAMA Neurology 2020. PMID: 32065623. View sourceStudy: Randomized double-blind placebo-controlled phase 2 trialSelf-administered subcutaneous zilucoplan produced rapid, dose-dependent, clinically meaningful improvement in generalized MG, supporting advancement to phase 3.
3. [3] Long-term safety and efficacy of zilucoplan in patients with generalized myasthenia gravis: interim analysis of the RAISE-XT open-label extension study — Howard JF Jr et al., Therapeutic Advances in Neurological Disorders 2024. PMID: 38638673. View sourceStudy: Open-label extension study (interim analysis)Longer-term open-label treatment sustained the clinical improvements seen in RAISE with a consistent safety profile.
4. [4] Zilucoplan, a macrocyclic peptide inhibitor of human complement component 5, uses a dual mode of action to prevent terminal complement activation — Tang GQ et al., Frontiers in Immunology 2023. PMID: 37622108. View sourceStudy: Preclinical/biochemical mechanistic studyBiochemical analysis showed zilucoplan blocks C5 cleavage and also prevents C5b-mediated assembly of the membrane attack complex, explaining its dual mechanism.
5. [5] Zilucoplan: First Approval — Shirley M et al., Drugs 2024. PMID: 38093160. View sourceStudy: Drug-approval reviewThis review summarizes zilucoplan's development, mechanism, pivotal RAISE data, and its regulatory approval for anti-AChR-positive generalized MG.
6. [6] Efficacy of zilucoplan in patients with generalised myasthenia gravis who have not previously received immunosuppressive/immunomodulatory therapy — Utsugisawa K et al., Journal of the Neurological Sciences 2025. PMID: 40450840. View sourceStudy: Post-hoc subgroup analysis of trial dataZilucoplan showed efficacy consistent with the overall population in patients who had not previously received immunosuppressive or immunomodulatory therapy.