Evidence review: Open Peptide Project (verified against primary PubMed, ClinicalTrials.gov & FDA records) · Last checked 2026-10-27. ← Back to Evidence Library

Zilucoplan (Zilbrysq): what the evidence says

Name: Zilucoplan (Zilbrysq)
Published: 2026-10-27

At a glance

What it is: a 15-amino-acid synthetic macrocyclic peptide that blocks complement protein C5, self-injected under the skin. Approved as Zilbrysq (Oct 2023) for adults with generalized myasthenia gravis who test positive for acetylcholine-receptor antibodies. An autoinjector option was approved in Oct 2026. ^{R1, R2, R3}

What the evidence says: Human in RAISE (174 adults), zilucoplan improved daily-living scores more than placebo over 12 weeks. ^R4

Biggest risks: boxed warning: serious, possibly fatal meningococcal infections; patients need meningococcal vaccination and the drug is available only through a restricted program (REMS). Pancreatitis and pancreatic cysts have also been reported. ^R2

Rating


Human Human evidence	Strong: phase 3 RCT (n = 174) ^R4
Animal Animal / lab evidence	Not reviewed
Regulatory	FDA-approved ^R1 · not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page ^{R5, R6, R7} · not named by WADA ^R8
Established human dose	Yes, label dose (see Study details)

Evidence verdict: Generalized myasthenia gravis (AChR-antibody positive): Strong (phase 3 RCT) · Other uses: No human data

This page reports what studies used. It is not dosing advice.

Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source

About the evidence: one pivotal placebo-controlled RCT of 12 weeks; longer data come from an open-label extension.

What is it?

Related pages: pegcetacoplan.

Does it work?

Human RAISE (12 weeks): MG-ADL score −4.39 vs −2.30 with placebo (difference −2.09). ^{R4, R9}
Human Adverse events 77% vs 70%; injection-site bruising was most common. ^R4

Is it safe?

Boxed warning: serious meningococcal infections; REMS program. ^R2
Warnings: other infections, pancreatitis and pancreatic cysts. ^R2
Most common: injection-site reactions, upper respiratory infection, diarrhea. ^R2

Gray-market vials: extra risks

A gray-market vial has no quality control and no guarantee of identity, strength or sterility. We test retail vials blind under the Open Peptide Standard; see /tests/. A passing test covers one batch on one date and does not mean the compound is safe.

Is it legal?

US: FDA-approved, prescription (Zilbrysq), restricted program (REMS). ^{R1, R2}
Compounding: not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page. ^{R5, R6, R7}
Sport: not named on WADA's 2026 Prohibited List. ^R8

Study details

These are amounts researchers used, not recommendations.

Study	People / model	Route	Amount used	Follow-up	Reported	Citation
RAISE 2023	174 adults with AChR+ generalized MG	SC	0.3 mg/kg daily	12 weeks	MG-ADL −4.39 vs −2.30 (placebo)	PMID 37059508

Full reference list (PubMed, CT.gov, FDA and WADA checked Oct 27, 2026)

^R1 Drugs@FDA, Zilbrysq (zilucoplan), application NDA216834 (openFDA drugsfda record checked Oct 27, 2026). https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=NDA216834
^R2 Zilbrysq prescribing information, label published Feb 5, 2026 (DailyMed, checked Oct 27, 2026). https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=9f1d53d6-e495-4a3a-8bb9-680a15d25034
^R3 UCB. UCB announces U.S. FDA approval for ZILBRYSQ (zilucoplan) autoinjector self-administration for adults living with generalized myasthenia gravis. Press release, Oct 16, 2026. https://www.ucb.com/newsroom/press-releases/article/ucb-announces-us-fda-approval-for-zilbrysqr-zilucoplan-autoinjector-self-administration-for-adults-living-with-generalized-myasthenia-gravis
^R4 Howard JF Jr, et al. Lancet Neurol. 2023. PMID 37059508
^R5 FDA, 503A bulk drug substances categories list (updated May 14, 2026). https://www.fda.gov/media/94155/download
^R6 FDA, 503B bulk drug substances categories list (updated Mar 21, 2025). https://www.fda.gov/media/94164/download
^R7 FDA, Certain bulk drug substances for use in compounding that may present significant safety risks (content current Apr 22, 2026). https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
^R8 WADA. The 2026 Prohibited List, full list checked; compound not named. https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf
^R9 ClinicalTrials.gov NCT04115293, RAISE, phase 3, completed, 174 enrolled (CT.gov API v2, checked Oct 27, 2026). https://clinicaltrials.gov/study/NCT04115293

Disclaimer

This page is for education and harm reduction, not medical advice or a recommendation to use Zilucoplan (Zilbrysq). This is a prescription medicine. Use it only under the care of a licensed clinician; do not buy it from research-chemical or gray-market sellers. Report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).