Nemolizumab-Ilto side effects: what 12,635 FDA adverse event reports show

Nemolizumab-Ilto · Nemluvio · 477 reaction terms · 24,184 drug–reaction co-reports · data 2026-09-14

Drug class

Interleukin-31 Receptor alpha Antagonist

FDA label (Established Pharmacologic Class)

Brand names

Nemluvio

openFDA label

Who reports

12,635 reports · 6% serious · 117 with death outcome · 68% female

openFDA FAERS counts, all years, deduplication not applied

Used for

NEMLUVIO is an interleukin-31 receptor antagonist indicated for: Prurigo Nodularis The treatment of adults with prurigo nodularis. ( 1.1 ) Atopic Dermatitis The treatment of adults and pediatric patients 12 years of age and older with moderate-to-sever.

FDA label, Indications and Usage

What it is

Nemolizumab-ilto, an interleukin-31 receptor alpha (IL-31RA) antagonist, is a humanized monoclonal modified immunoglobulin G (IgG) antibody with a molecular weight of approximately 144 kDa. Nemolizumab-ilto is produced by recombinant DNA technology in Chinese Hamster Ovary cells.

FDA label, Description section

Boxed warning

None in the current 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 40 strongest signals

Labeled adverse reaction 3Labeled (related wording) 1Likely indication confounding 1Reporting / coding artifact 11Not in label — unassessed 24

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.
Likely indication confounding The term appears in the label's indications: reports probably describe the disease being treated (or its progression), not a drug effect. Classic confounding by indication.
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. 437 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
Neurodermatitis	272	140.6 124.3–158.9ROR 143.6 · χ² 34,587 / p <1e-300	128.4 EB05 116.1 · IC025 +6.5 3/3 methods agree	Not in label — unassessed	serious n=12 · 83% consumer	no trial data cached
Needle track marks	20	85.7 54.7–134.3ROR 85.8 · χ² 1,511 / p <1e-300	75.8 EB05 51.8 · IC025 +4.0 3/3 methods agree	Not in label — unassessed	100% consumer	no trial data cached
Eczema nummular	21	78.6 50.8–121.8ROR 78.8 · χ² 1,463 / p <1e-300	70.5 EB05 48.6 · IC025 +4.1 3/3 methods agree	Labeled adverse reaction exact term	serious n=2 · 76% consumer	no trial data cached
Device malfunction	2,066	52.6 50.6–54.8ROR 62.7 · χ² 101,655 / p <1e-300	51.0 EB05 49.2 · IC025 +5.6 3/3 methods agree	Reporting / coding artifact	serious PRR 11.4 · 87% consumer	no trial data cached
Skin weeping	86	44.0 35.6–54.5ROR 44.3 · χ² 3,480 / p <1e-300	42.5 EB05 35.5 · IC025 +4.8 3/3 methods agree	Not in label — unassessed	serious n=12 · 88% consumer	no trial data cached
Device use issue	269	26.2 23.2–29.5ROR 26.7 · χ² 6,393 / p <1e-300	25.7 EB05 23.3 · IC025 +4.4 3/3 methods agree	Reporting / coding artifact	serious n=1 · 91% consumer	no trial data cached
Product dose omission issue	4,300	25.4 24.8–26.1ROR 38.0 · χ² 100,742 / p <1e-300	25.1 EB05 24.4 · IC025 +4.6 3/3 methods agree	Reporting / coding artifact	serious PRR 16.3 · 96% consumer	no trial data cached
Skin texture abnormal	13	23.3 13.5–40.2ROR 23.3 · χ² 252 / p 5e-57	22.2 EB05 13.5 · IC025 +2.7 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Product reconstitution quality issue	10	19.4 10.4–36.2ROR 19.4 · χ² 155 / p 7e-36	17.9 EB05 9.4 · IC025 +2.3 3/3 methods agree	Reporting / coding artifact	–	no trial data cached
Dermatitis atopic	478	16.0 14.7–17.5ROR 16.6 · χ² 6,669 / p <1e-300	15.9 EB05 14.7 · IC025 +3.8 3/3 methods agree	Labeled adverse reaction exact term	serious n=24 · 84% consumer	no trial data cached
Device use error	315	15.5 13.9–17.3ROR 15.8 · χ² 4,217 / p <1e-300	15.3 EB05 13.9 · IC025 +3.7 3/3 methods agree	Reporting / coding artifact	serious n=6 · 95% consumer	no trial data cached
Inappropriate schedule of product administration	1,487	14.1 13.4–14.8ROR 15.8 · χ² 18,037 / p <1e-300	14.0 EB05 13.4 · IC025 +3.7 3/3 methods agree	Reporting / coding artifact	serious PRR 6.2 · 95% consumer	no trial data cached
Device leakage	339	13.4 12.0–14.9ROR 13.7 · χ² 3,850 / p <1e-300	13.3 EB05 12.1 · IC025 +3.5 3/3 methods agree	Reporting / coding artifact	serious n=2 · 88% consumer	no trial data cached
Intentional underdose	57	13.1 10.1–17.0ROR 13.1 · χ² 619 / p 7e-137	12.8 EB05 10.1 · IC025 +3.1 3/3 methods agree	Not in label — unassessed	serious n=3 · 86% consumer	no trial data cached
Rash papular	172	12.8 11.0–14.9ROR 13.0 · χ² 1,846 / p <1e-300	12.6 EB05 11.1 · IC025 +3.4 3/3 methods agree	Not in label — unassessed	serious PRR 10.2 · 96% consumer	no trial data cached
Device defective	116	12.0 10.0–14.4ROR 12.1 · χ² 1,148 / p 6e-252	11.8 EB05 10.1 · IC025 +3.2 3/3 methods agree	Reporting / coding artifact	98% consumer	no trial data cached
Eczema	341	11.3 10.2–12.6ROR 11.6 · χ² 3,184 / p <1e-300	11.2 EB05 10.2 · IC025 +3.3 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 23.0 · 76% consumer	no trial data cached
Dermatitis exfoliative generalised	20	9.7 6.3–15.1ROR 9.7 · χ² 147 / p 4e-34	8.6 EB05 5.6 · IC025 +2.2 3/3 methods agree	Not in label — unassessed	serious n=20	no trial data cached
Incorrect dose administered	1,258	9.3 8.9–9.8ROR 10.3 · χ² 9,395 / p <1e-300	9.3 EB05 8.8 · IC025 +3.1 3/3 methods agree	Reporting / coding artifact	serious PRR 0.8 · 83% consumer	no trial data cached
Skin discomfort	13	8.1 4.7–14.0ROR 8.2 · χ² 74 / p 4e-18	6.7 EB05 4.0 · IC025 +1.7 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Skin mass	31	7.8 5.5–11.1ROR 7.8 · χ² 176 / p 2e-40	7.1 EB05 5.2 · IC025 +2.2 3/3 methods agree	Not in label — unassessed	serious n=4 · 81% consumer	no trial data cached
Skin hyperpigmentation	32	6.2 4.4–8.8ROR 6.2 · χ² 134 / p 2e-31	5.7 EB05 4.2 · IC025 +1.9 3/3 methods agree	Not in label — unassessed	serious n=2 · 97% consumer	no trial data cached
Skin haemorrhage	53	6.1 4.7–8.0ROR 6.1 · χ² 221 / p 3e-50	5.8 EB05 4.6 · IC025 +2.1 3/3 methods agree	Not in label — unassessed	serious n=6 · 83% consumer	no trial data cached
Skin swelling	31	6.1 4.3–8.6ROR 6.1 · χ² 126 / p 2e-29	5.6 EB05 4.1 · IC025 +1.9 3/3 methods agree	Not in label — unassessed	serious n=2 · 81% consumer	no trial data cached
Scab	41	6.0 4.4–8.2ROR 6.0 · χ² 166 / p 3e-38	5.6 EB05 4.3 · IC025 +2.0 3/3 methods agree	Not in label — unassessed	serious n=2 · 93% consumer	no trial data cached
Skin hypertrophy	10	5.9 3.2–11.1ROR 5.9 · χ² 36 / p 9e-10	4.8 EB05 2.8 · IC025 +1.2 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Pruritus (itching)	1,274	5.6 5.3–5.9ROR 6.1 · χ² 4,893 / p <1e-300	5.6 EB05 5.3 · IC025 +2.4 3/3 methods agree	Not in label — unassessed	serious PRR 5.7 · 86% consumer	no trial data cached
Purulent discharge	14	5.4 3.2–9.2ROR 5.5 · χ² 46 / p 5e-12	4.7 EB05 3.0 · IC025 +1.3 3/3 methods agree	Not in label — unassessed	serious n=3	no trial data cached
Skin warm	18	5.1 3.2–8.2ROR 5.2 · χ² 56 / p 4e-14	4.6 EB05 3.1 · IC025 +1.4 3/3 methods agree	Not in label — unassessed	serious n=1	no trial data cached
Pain of skin	79	4.9 3.9–6.1ROR 4.9 · χ² 238 / p 4e-54	4.7 EB05 3.9 · IC025 +1.9 3/3 methods agree	Not in label — unassessed	serious PRR 15.0 · 86% consumer	no trial data cached
Skin fissures	54	4.8 3.6–6.2ROR 4.8 · χ² 156 / p 4e-36	4.6 EB05 3.6 · IC025 +1.7 3/3 methods agree	Not in label — unassessed	serious n=4 · 81% consumer	no trial data cached
Pemphigoid	21	4.7 3.1–7.2ROR 4.7 · χ² 58 / p 2e-14	4.3 EB05 3.0 · IC025 +1.4 3/3 methods agree	Not in label — unassessed	serious PRR 43.9 · 100% clinician	no trial data cached
Skin exfoliation	235	4.7 4.1–5.3ROR 4.8 · χ² 682 / p 1e-150	4.7 EB05 4.2 · IC025 +2.0 3/3 methods agree	Not in label — unassessed	serious PRR 16.2 · 84% consumer	no trial data cached
Intentional product use issue	230	4.3 3.8–4.9ROR 4.4 · χ² 591 / p 9e-131	4.3 EB05 3.9 · IC025 +1.9 3/3 methods agree	Reporting / coding artifact	serious PRR 3.3 · 91% consumer	no trial data cached
Skin ulcer	63	4.1 3.2–5.2ROR 4.1 · χ² 142 / p 5e-33	3.9 EB05 3.2 · IC025 +1.6 3/3 methods agree	Not in label — unassessed	serious PRR 2.3 · 95% consumer	no trial data cached
Drug effect less than expected	34	4.0 2.9–5.6ROR 4.0 · χ² 74 / p 5e-18	3.8 EB05 2.9 · IC025 +1.4 3/3 methods agree	Reporting / coding artifact	serious n=2 · 71% consumer	no trial data cached
Injection site haemorrhage	191	4.0 3.5–4.6ROR 4.0 · χ² 428 / p 3e-95	4.0 EB05 3.5 · IC025 +1.7 3/3 methods agree	Labeled (related wording) related wording	serious PRR 4.3 · 92% consumer	no trial data cached
Skin tightness	11	3.9 2.2–7.0ROR 3.9 · χ² 21 / p 2e-6	3.4 EB05 2.1 · IC025 +0.8 3/3 methods agree	Not in label — unassessed	serious n=2	no trial data cached
Dermatitis	46	3.7 2.8–4.9ROR 3.7 · χ² 87 / p 4e-21	3.6 EB05 2.8 · IC025 +1.3 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 3.0	no trial data cached
Periorbital swelling	12	3.6 2.1–6.4ROR 3.6 · χ² 20 / p 3e-6	3.3 EB05 2.0 · IC025 +0.7 3/3 methods agree	Not in label — unassessed	serious n=1	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	4,300	25.4 24.8–26.1ROR 38.0 · χ² 100,742 / p <1e-300	25.1 EB05 24.4 · IC025 +4.6 3/3 methods agree	Reporting / coding artifact	serious PRR 16.3 · 96% consumer	no trial data cached
Device malfunction	2,066	52.6 50.6–54.8ROR 62.7 · χ² 101,655 / p <1e-300	51.0 EB05 49.2 · IC025 +5.6 3/3 methods agree	Reporting / coding artifact	serious PRR 11.4 · 87% consumer	no trial data cached
Inappropriate schedule of product administration	1,487	14.1 13.4–14.8ROR 15.8 · χ² 18,037 / p <1e-300	14.0 EB05 13.4 · IC025 +3.7 3/3 methods agree	Reporting / coding artifact	serious PRR 6.2 · 95% consumer	no trial data cached
Pruritus (itching)	1,274	5.6 5.3–5.9ROR 6.1 · χ² 4,893 / p <1e-300	5.6 EB05 5.3 · IC025 +2.4 3/3 methods agree	Not in label — unassessed	serious PRR 5.7 · 86% consumer	no trial data cached
Incorrect dose administered	1,258	9.3 8.9–9.8ROR 10.3 · χ² 9,395 / p <1e-300	9.3 EB05 8.8 · IC025 +3.1 3/3 methods agree	Reporting / coding artifact	serious PRR 0.8 · 83% consumer	no trial data cached
Rash	832	3.2 3.0–3.4ROR 3.3 · χ² 1,271 / p 9e-279	3.2 EB05 3.0 · IC025 +1.6 3/3 methods agree	Not in label — unassessed	serious PRR 3.9 · 80% consumer	no trial data cached
Drug ineffective (drug did not work)	699	0.9 0.8–0.9ROR 0.9 · χ² 12 / p 3e-4	0.9 EB05 0.8 · IC025 -0.3 PRR-only: not supported by EBGM or IC	Reporting / coding artifact	serious PRR 0.6 · 87% consumer	no trial data cached
Dermatitis atopic	478	16.0 14.7–17.5ROR 16.6 · χ² 6,669 / p <1e-300	15.9 EB05 14.7 · IC025 +3.8 3/3 methods agree	Labeled adverse reaction exact term	serious n=24 · 84% consumer	no trial data cached
Headache	433	1.1 1.0–1.3ROR 1.2 · χ² 8 / p 0.002	1.1 EB05 1.1 · IC025 +0.0	Labeled adverse reaction exact term	serious PRR 1.6 · 91% consumer	no trial data cached
Eczema	341	11.3 10.2–12.6ROR 11.6 · χ² 3,184 / p <1e-300	11.2 EB05 10.2 · IC025 +3.3 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 23.0 · 76% consumer	no trial data cached
Device leakage	339	13.4 12.0–14.9ROR 13.7 · χ² 3,850 / p <1e-300	13.3 EB05 12.1 · IC025 +3.5 3/3 methods agree	Reporting / coding artifact	serious n=2 · 88% consumer	no trial data cached
Device use error	315	15.5 13.9–17.3ROR 15.8 · χ² 4,217 / p <1e-300	15.3 EB05 13.9 · IC025 +3.7 3/3 methods agree	Reporting / coding artifact	serious n=6 · 95% consumer	no trial data cached
Dry skin	287	3.6 3.2–4.1ROR 3.7 · χ² 545 / p 6e-121	3.6 EB05 3.3 · IC025 +1.7 3/3 methods agree	Not in label — unassessed	serious PRR 9.0 · 87% consumer	no trial data cached
Arthralgia (joint pain)	280	1.1 1.0–1.3ROR 1.1 · χ² 4 / p 0.028	1.1 EB05 1.0 · IC025 -0.0 PRR-only: not supported by EBGM or IC	Labeled adverse reaction exact term	serious PRR 1.3 · 80% consumer	no trial data cached
Neurodermatitis	272	140.6 124.3–158.9ROR 143.6 · χ² 34,587 / p <1e-300	128.4 EB05 116.1 · IC025 +6.5 3/3 methods agree	Not in label — unassessed	serious n=12 · 83% consumer	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.

Neurodermatitis — n=272, PRR 140.6
Needle track marks — n=20, PRR 85.7
Skin weeping — n=86, PRR 44.0
Intentional underdose — n=57, PRR 13.1
Rash papular — n=172, PRR 12.8
Dermatitis exfoliative generalised — n=20, PRR 9.7
Skin mass — n=31, PRR 7.8
Skin hyperpigmentation — n=32, PRR 6.2
Skin haemorrhage — n=53, PRR 6.1
Skin swelling — n=31, PRR 6.1

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 Nemolizumab-Ilto?

In FDA FAERS, the most frequently co-reported reaction terms for Nemolizumab-Ilto are pruritus, rash, dermatitis atopic, headache, eczema, dry skin. 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 Nemolizumab-Ilto have an FDA boxed warning?

No. The FDA label retrieved for Nemolizumab-Ilto has no boxed warning; see the label's Warnings and Precautions for the recognised risks.

Do FAERS signals prove that Nemolizumab-Ilto 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 e9229ef1-ac60-4c24-afb6-009d3c781687, effective 20250626; matched on openfda.generic_name.exact:"NEMOLIZUMAB-ILTO")
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, 477 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.