Zilucoplan side effects: what 816 FDA adverse event reports show

Zilucoplan · Zilbrysq · 35 reaction terms · 759 drug–reaction co-reports · data 2026-09-14

Drug class

Complement Inhibitor

FDA label (Established Pharmacologic Class) · compare the class

Brand names

Zilbrysq

openFDA label

Who reports

816 reports · 82% serious · 40 with death outcome · 55% female

openFDA FAERS counts, all years, deduplication not applied

Used for

ZILBRYSQ is indicated for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) antibody positive. ZILBRYSQ is a complement inhibitor indicated for the treatment of generalized myasthenia gravis (gMG) in adult patients who are anti-acetylcholine receptor (AChR) antibody positive. ( 1 )

FDA label, Indications and Usage

What it is

Zilucoplan, a complement inhibitor, is a 15 amino-acid, synthetic macrocyclic peptide.

FDA label, Description section

Boxed warning

SERIOUS MENINGOCOCCAL INFECTIONS ZILBRYSQ, a complement inhibitor, increases the risk of serious infections caused by Neisseria meningitidis [see Warnings and Precautions (5.1) ] . Life-threatening and fatal meningococcal infections have occurred in patients treated with complement inhibitors.

FDA label

How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation. Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)? That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.

Causality screen of the 24 strongest signals

Labeled adverse reaction 1Labeled (related wording) 8Reporting / coding artifact 10Not in label — unassessed 5

What the badges mean

Labeled adverse reaction The exact term appears in the label's warnings or adverse-reactions sections: a known, expected effect. The FAERS signal confirms the label rather than discovering anything.
Labeled (related wording) The label describes this effect under different wording (e.g. 'neutropenia' for 'neutrophil count decreased'). Treated as known.
Reporting / coding artifact An administrative, monitoring or exposure term (product issue, off-label use, 'test normal', overdose...). Not a biological reaction; a high PRR here reflects how reports are coded.
Not in label — unassessed Not found in the label text, not an artifact pattern. This is a genuine candidate for a formal causality assessment (Bradford Hill / WHO-UMC); it has NOT had one here.

Strongest disproportionality signals

Flagged terms (PRR ≥ 2, χ² ≥ 4, n ≥ 10), ranked by PRR; infinite PRRs (no comparator reports) excluded. The EBGM column is a second, shrinkage-based estimate (MGPS) with its 5th percentile EB05 and the BCPNN IC025; a pair flagged by PRR alone is marked PRR-only and should be read as fragile. The strata column recomputes the PRR on serious reports only and flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 11 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.

Show: hide coding/lab/outcome terms hide indication terms unlabeled only hide PRR-only

Reaction	Reports	PRR 95% CI · ROR · χ²/p	EBGM EB05 · IC025	Label screen	Serious-only & strata	Trial cross-check
Syringe issue	35	51.4 37.1–71.0ROR 53.6 · χ² 1,676 / p <1e-300	49.9 EB05 37.5 · IC025 +4.3 3/3 methods agree	Not in label — unassessed	serious n=28 · 80% consumer	no trial data cached
Insurance issue	24	41.5 28.0–61.6ROR 42.8 · χ² 908 / p 8e-200	40.2 EB05 28.5 · IC025 +3.8 3/3 methods agree	Not in label — unassessed	serious PRR 55.4 · 79% consumer	no trial data cached
Eyelid ptosis	13	32.8 19.1–56.3ROR 33.4 · χ² 370 / p 1e-82	31.4 EB05 19.5 · IC025 +3.0 3/3 methods agree	Not in label — unassessed	serious n=9	no trial data cached
Product dose omission in error	28	26.8 18.6–38.6ROR 27.7 · χ² 670 / p 6e-148	26.3 EB05 19.1 · IC025 +3.6 3/3 methods agree	Reporting / coding artifact	serious PRR 55.8 · 96% consumer	no trial data cached
Needle issue	29	26.0 18.2–37.2ROR 27.0 · χ² 674 / p 7e-149	25.6 EB05 18.7 · IC025 +3.6 3/3 methods agree	Not in label — unassessed	serious n=18 · 83% consumer	no trial data cached
Intentional dose omission	22	20.7 13.7–31.2ROR 21.2 · χ² 392 / p 1e-87	20.3 EB05 14.0 · IC025 +3.1 3/3 methods agree	Reporting / coding artifact	serious PRR 27.2 · 77% consumer	no trial data cached
Injection site induration	10	19.8 10.7–36.7ROR 20.0 · χ² 160 / p 5e-37	18.6 EB05 9.9 · IC025 +2.3 3/3 methods agree	Labeled (related wording) related wording	serious n=10	no trial data cached
Cytokine release syndrome	12	16.2 9.2–28.4ROR 16.4 · χ² 156 / p 4e-36	15.0 EB05 8.3 · IC025 +2.4 3/3 methods agree	Not in label — unassessed	serious PRR 11.5	no trial data cached
Product availability issue	13	14.9 8.7–25.5ROR 15.1 · χ² 155 / p 7e-36	13.8 EB05 7.7 · IC025 +2.4 3/3 methods agree	Reporting / coding artifact	serious PRR 16.8	no trial data cached
Therapy interrupted	34	12.7 9.1–17.6ROR 13.2 · χ² 354 / p 2e-79	12.3 EB05 8.9 · IC025 +2.9 3/3 methods agree	Reporting / coding artifact	serious PRR 19.2 · 79% consumer	no trial data cached
Product dose omission issue	129	11.6 9.9–13.6ROR 13.6 · χ² 1,260 / p 3e-276	11.5 EB05 9.9 · IC025 +3.2 3/3 methods agree	Reporting / coding artifact	serious PRR 25.9 · 92% consumer	no trial data cached
Hospitalisation	62	10.4 8.2–13.3ROR 11.2 · χ² 524 / p 3e-116	10.2 EB05 8.1 · IC025 +2.9 3/3 methods agree	Reporting / coding artifact	serious PRR 7.5 · 73% consumer	no trial data cached
Injection site bruising	32	10.4 7.4–14.6ROR 10.8 · χ² 264 / p 1e-59	9.8 EB05 7.1 · IC025 +2.6 3/3 methods agree	Labeled (related wording) related wording	serious PRR 34.7 · 72% consumer	no trial data cached
Therapeutic response decreased	24	10.2 6.9–15.2ROR 10.5 · χ² 191 / p 1e-43	9.4 EB05 6.4 · IC025 +2.4 3/3 methods agree	Reporting / coding artifact	serious PRR 18.4	no trial data cached
Injection site mass	14	9.8 5.8–16.4ROR 9.9 · χ² 102 / p 4e-24	8.3 EB05 4.9 · IC025 +2.0 3/3 methods agree	Labeled (related wording) related wording	serious PRR 36.6	no trial data cached
Device issue	32	9.4 6.7–13.2ROR 9.8 · χ² 233 / p 6e-53	8.8 EB05 6.3 · IC025 +2.5 3/3 methods agree	Reporting / coding artifact	serious PRR 19.6 · 81% consumer	no trial data cached
Injection site pruritus	24	9.3 6.2–13.7ROR 9.5 · χ² 169 / p 6e-39	8.4 EB05 5.7 · IC025 +2.3 3/3 methods agree	Labeled (related wording) related wording	serious PRR 42.2 · 71% consumer	no trial data cached
Therapeutic response shortened	11	8.9 4.9–16.0ROR 9.0 · χ² 69 / p 4e-17	7.1 EB05 4.0 · IC025 +1.7 3/3 methods agree	Reporting / coding artifact	serious PRR 15.0	no trial data cached
Injection site rash	10	8.5 4.6–15.7ROR 8.6 · χ² 59 / p 1e-14	6.6 EB05 3.7 · IC025 +1.6 3/3 methods agree	Labeled (related wording) related wording	serious n=10	no trial data cached
Injection site pain (pain where injected)	95	8.0 6.7–9.7ROR 9.0 · χ² 586 / p 7e-130	7.8 EB05 6.6 · IC025 +2.6 3/3 methods agree	Labeled (related wording) related wording	serious PRR 30.3 · 81% consumer	no trial data cached
Injection site swelling	15	5.1 3.1–8.4ROR 5.2 · χ² 45 / p 8e-12	4.4 EB05 2.9 · IC025 +1.3 3/3 methods agree	Labeled (related wording) related wording	serious PRR 23.2	no trial data cached
Injection site reaction	12	4.5 2.6–7.9ROR 4.5 · χ² 29 / p 3e-8	3.9 EB05 2.4 · IC025 +1.0 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 13.6	no trial data cached
Product storage error	11	3.3 1.8–5.9ROR 3.3 · χ² 15 / p 5e-5	2.9 EB05 1.8 · IC025 +0.5	Reporting / coding artifact	serious PRR 24.7	no trial data cached
Injection site haemorrhage	10	3.2 1.7–6.0ROR 3.3 · χ² 13 / p 1e-4	2.9 EB05 1.7 · IC025 +0.5	Labeled (related wording) related wording	serious PRR 11.9	no trial data cached

Trial evidence (ClinicalTrials.gov)

Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).

Most frequently reported reactions

By raw co-report count, regardless of disproportionality. Common terms here are often the illness itself or generic outcomes.

Reaction	Reports	PRR 95% CI · ROR · χ²/p	EBGM EB05 · IC025	Label screen	Serious-only & strata	Trial cross-check
Product dose omission issue	129	11.6 9.9–13.6ROR 13.6 · χ² 1,260 / p 3e-276	11.5 EB05 9.9 · IC025 +3.2 3/3 methods agree	Reporting / coding artifact	serious PRR 25.9 · 92% consumer	no trial data cached
Injection site pain (pain where injected)	95	8.0 6.7–9.7ROR 9.0 · χ² 586 / p 7e-130	7.8 EB05 6.6 · IC025 +2.6 3/3 methods agree	Labeled (related wording) related wording	serious PRR 30.3 · 81% consumer	no trial data cached
Hospitalisation	62	10.4 8.2–13.3ROR 11.2 · χ² 524 / p 3e-116	10.2 EB05 8.1 · IC025 +2.9 3/3 methods agree	Reporting / coding artifact	serious PRR 7.5 · 73% consumer	no trial data cached
Syringe issue	35	51.4 37.1–71.0ROR 53.6 · χ² 1,676 / p <1e-300	49.9 EB05 37.5 · IC025 +4.3 3/3 methods agree	Not in label — unassessed	serious n=28 · 80% consumer	no trial data cached
Therapy interrupted	34	12.7 9.1–17.6ROR 13.2 · χ² 354 / p 2e-79	12.3 EB05 8.9 · IC025 +2.9 3/3 methods agree	Reporting / coding artifact	serious PRR 19.2 · 79% consumer	no trial data cached
Device issue	32	9.4 6.7–13.2ROR 9.8 · χ² 233 / p 6e-53	8.8 EB05 6.3 · IC025 +2.5 3/3 methods agree	Reporting / coding artifact	serious PRR 19.6 · 81% consumer	no trial data cached
Injection site bruising	32	10.4 7.4–14.6ROR 10.8 · χ² 264 / p 1e-59	9.8 EB05 7.1 · IC025 +2.6 3/3 methods agree	Labeled (related wording) related wording	serious PRR 34.7 · 72% consumer	no trial data cached
Needle issue	29	26.0 18.2–37.2ROR 27.0 · χ² 674 / p 7e-149	25.6 EB05 18.7 · IC025 +3.6 3/3 methods agree	Not in label — unassessed	serious n=18 · 83% consumer	no trial data cached
Product dose omission in error	28	26.8 18.6–38.6ROR 27.7 · χ² 670 / p 6e-148	26.3 EB05 19.1 · IC025 +3.6 3/3 methods agree	Reporting / coding artifact	serious PRR 55.8 · 96% consumer	no trial data cached
Injection site pruritus	24	9.3 6.2–13.7ROR 9.5 · χ² 169 / p 6e-39	8.4 EB05 5.7 · IC025 +2.3 3/3 methods agree	Labeled (related wording) related wording	serious PRR 42.2 · 71% consumer	no trial data cached
Therapeutic response decreased	24	10.2 6.9–15.2ROR 10.5 · χ² 191 / p 1e-43	9.4 EB05 6.4 · IC025 +2.4 3/3 methods agree	Reporting / coding artifact	serious PRR 18.4	no trial data cached
Insurance issue	24	41.5 28.0–61.6ROR 42.8 · χ² 908 / p 8e-200	40.2 EB05 28.5 · IC025 +3.8 3/3 methods agree	Not in label — unassessed	serious PRR 55.4 · 79% consumer	no trial data cached
Intentional dose omission	22	20.7 13.7–31.2ROR 21.2 · χ² 392 / p 1e-87	20.3 EB05 14.0 · IC025 +3.1 3/3 methods agree	Reporting / coding artifact	serious PRR 27.2 · 77% consumer	no trial data cached
Injection site swelling	15	5.1 3.1–8.4ROR 5.2 · χ² 45 / p 8e-12	4.4 EB05 2.9 · IC025 +1.3 3/3 methods agree	Labeled (related wording) related wording	serious PRR 23.2	no trial data cached
Injection site mass	14	9.8 5.8–16.4ROR 9.9 · χ² 102 / p 4e-24	8.3 EB05 4.9 · IC025 +2.0 3/3 methods agree	Labeled (related wording) related wording	serious PRR 36.6	no trial data cached

Unlabeled candidate signals

These flagged terms were not found in the FDA label text and do not match an artifact pattern. They are the pairs that would merit a structured assessment (temporality, dose-response, biological plausibility, consistency across databases, trial or cohort evidence). The screen has not done that; string-matching misses label wording, and a strong PRR can still be stimulated reporting, co-medication, or the disease itself.

Syringe issue — n=35, PRR 51.4
Insurance issue — n=24, PRR 41.5
Needle issue — n=29, PRR 26.0

Want to assess one of these properly? The runbook describes the Bradford Hill / trial-evidence workflow used on the assessment page, and handoff_top1000_signals.csv lists the strongest unassessed pairs across all drugs.

Common questions

What are the most reported side effects of Zilucoplan?

In FDA FAERS, the most frequently co-reported reaction terms for Zilucoplan are injection site pain, syringe issue, injection site bruising, needle issue, injection site pruritus, insurance issue. These are report counts, not rates: FAERS has no denominator, reporting is voluntary and uneven, and a term can be reported because of the illness being treated rather than the drug.

Does Zilucoplan have an FDA boxed warning?

Yes. The current FDA label carries a boxed warning: SERIOUS MENINGOCOCCAL INFECTIONS ZILBRYSQ, a complement inhibitor, increases the risk of serious infections caused by Neisseria meningitidis [see Warnings and Precautions (5.1) ] . Life-threatening and fatal meningococcal infections have occurred in patients treated with complement inhibitors.

Do FAERS signals prove that Zilucoplan causes these side effects?

No. A disproportionality signal (PRR, ROR) means a reaction is reported more often with this drug than with others in the database. That can reflect a real effect, but also the disease being treated, stimulated reporting after news or litigation, co-medications, or how reports are coded. Causality needs temporality, dose-response, biological plausibility, consistency across data sources and, ideally, trial or cohort evidence. This page screens each term against the FDA label and ClinicalTrials.gov results; it does not establish causation.

Sources & methods

FDA label via openFDA (set ID 9f1d53d6-e495-4a3a-8bb9-680a15d25034, effective 20260203; matched on openfda.generic_name.exact:"ZILUCOPLAN")
Bayesian shrinkage measures computed offline over all 1,317,300 cached pairs: BCPNN information component (IC, with Norén closed-form IC025) and MGPS empirical-Bayes geometric mean (EBGM, EB05) with a two-component gamma prior fitted by maximum marginal likelihood (α₁=0.57, β₁=0.02, α₂=1.42, β₂=0.70, w=0.17); unstratified
FAERS pair statistics from the OpenPV build of 2026-09-14 (openFDA count= aggregation, field patient.drug.openfda.generic_name.exact, 35 reaction terms, min 3 co-reports); PRR/ROR with 95% CI, chi-square with Yates correction
Serious-only and stratified counts (serious:1, patient.patientsex, primarysource.qualification) from openFDA count queries; serious-only PRR uses the drug serious report total and the term global serious total (N_serious=11,882,979); strata shown only when n ≥ 20
Seriousness and sex counts from openFDA count=serious, patient.patientsex, seriousnessdeath

Page generated 2026-10-08. Label and PubChem text are retrieved automatically and may lag the current label; always check the current prescribing information. OpenPV is a beta research tool of the Open Source Medicine Foundation.