Belumosudil side effects: what 3,180 FDA adverse event reports show

Belumosudil · Rezurock · 73 reaction terms · 2,231 drug–reaction co-reports · data 2026-09-14

Drug class

Kinase inhibitor

FDA label, Indications wording

Brand names

Rezurock

openFDA label

Who reports

3,180 reports · 50% serious · 287 with death outcome · 47% female

openFDA FAERS counts, all years, deduplication not applied

Used for

REZUROCK is indicated for the treatment of adult and pediatric patients 12 years and older with chronic graft-versus-host disease (chronic GVHD) after failure of at least two prior lines of systemic therapy. REZUROCK is a kinase inhibitor indicated for.

FDA label, Indications and Usage

What it is

Belumosudil is a kinase inhibitor. The active pharmaceutical ingredient is belumosudil mesylate with the molecular formula C 27 H 28 N 6 O 5 S and the molecular weight is 548.62 g/mol.

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 37 strongest signals

Labeled adverse reaction 5Labeled (related wording) 4Reporting / coding artifact 8Lab value / disease marker 6Not in label — unassessed 14

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.
Lab value / disease marker A laboratory result, investigation or disease-activity marker (antibody positive, CRP abnormal, swollen joint count) not described in the label. These usually mirror the monitored disease or testing protocol rather than a drug effect; not screened further.
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. 36 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
Inappropriate schedule of product administration	440	16.4 15.1–17.9ROR 18.9 · χ² 6,400 / p <1e-300	16.4 EB05 15.1 · IC025 +3.9 3/3 methods agree	Reporting / coding artifact	serious PRR 25.2	no trial data cached
Product use in unapproved indication	454	12.3 11.3–13.4ROR 14.1 · χ² 4,732 / p <1e-300	12.2 EB05 11.3 · IC025 +3.4 3/3 methods agree	Reporting / coding artifact	serious PRR 16.8	no trial data cached
Decreased activity	17	10.5 6.5–16.8ROR 10.5 · χ² 136 / p 9e-32	9.2 EB05 5.8 · IC025 +2.2 3/3 methods agree	Not in label — unassessed	serious PRR 7.5	no trial data cached
Product dose omission in error	30	7.4 5.2–10.5ROR 7.4 · χ² 159 / p 1e-36	6.7 EB05 4.9 · IC025 +2.1 3/3 methods agree	Reporting / coding artifact	serious PRR 5.6	no trial data cached
Dry eye	54	7.3 5.6–9.6ROR 7.5 · χ² 290 / p 2e-65	7.0 EB05 5.5 · IC025 +2.3 3/3 methods agree	Not in label — unassessed	serious PRR 8.1	no trial data cached
Hospitalisation	145	6.3 5.4–7.4ROR 6.5 · χ² 642 / p 7e-142	6.2 EB05 5.4 · IC025 +2.3 3/3 methods agree	Reporting / coding artifact	serious PRR 7.3	no trial data cached
Cytopenia	11	6.1 3.4–10.9ROR 6.1 · χ² 42 / p 6e-11	4.9 EB05 3.0 · IC025 +1.3 3/3 methods agree	Not in label — unassessed	serious PRR 7.2	no trial data cached
Liver function test increased	19	5.9 3.8–9.2ROR 5.9 · χ² 72 / p 1e-17	5.2 EB05 3.5 · IC025 +1.6 3/3 methods agree	Labeled (related wording) related wording	serious PRR 5.0	no trial data cached
Emotional disorder	26	5.5 3.8–8.1ROR 5.6 · χ² 92 / p 4e-22	5.1 EB05 3.6 · IC025 +1.7 3/3 methods agree	Not in label — unassessed	serious PRR 5.8	no trial data cached
Depressed mood	40	5.0 3.7–6.8ROR 5.1 · χ² 125 / p 3e-29	4.7 EB05 3.6 · IC025 +1.7 3/3 methods agree	Not in label — unassessed	serious PRR 3.3	no trial data cached
Bacterial infection	14	5.0 2.9–8.4ROR 5.0 · χ² 41 / p 1e-10	4.3 EB05 2.8 · IC025 +1.2 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 5.7	no trial data cached
Full blood count decreased	15	4.9 3.0–8.1ROR 4.9 · χ² 43 / p 3e-11	4.3 EB05 2.8 · IC025 +1.3 3/3 methods agree	Lab value / disease marker	serious PRR 3.8	no trial data cached
Muscle tightness	12	4.9 2.8–8.6ROR 4.9 · χ² 33 / p 4e-9	4.2 EB05 2.6 · IC025 +1.1 3/3 methods agree	Not in label — unassessed	serious PRR 0.9	no trial data cached
Blood bilirubin increased	19	4.6 3.0–7.2ROR 4.6 · χ² 50 / p 6e-13	4.2 EB05 2.8 · IC025 +1.3 3/3 methods agree	Lab value / disease marker	serious PRR 3.2	no trial data cached
Hepatic enzyme increased	45	4.4 3.3–5.8ROR 4.4 · χ² 114 / p 8e-27	4.2 EB05 3.3 · IC025 +1.6 3/3 methods agree	Lab value / disease marker	serious PRR 2.7	no trial data cached
Disease progression	77	4.3 3.5–5.4ROR 4.4 · χ² 193 / p 4e-44	4.2 EB05 3.5 · IC025 +1.7 3/3 methods agree	Reporting / coding artifact	serious PRR 4.8	no trial data cached
Loss of personal independence in daily activities	31	4.3 3.0–6.1ROR 4.3 · χ² 75 / p 2e-18	4.1 EB05 3.0 · IC025 +1.4 3/3 methods agree	Not in label — unassessed	serious PRR 3.4	no trial data cached
Acute myeloid leukaemia	10	4.2 2.3–7.9ROR 4.2 · χ² 22 / p 2e-6	3.6 EB05 2.1 · IC025 +0.8 3/3 methods agree	Not in label — unassessed	serious PRR 4.9	no trial data cached
Musculoskeletal discomfort	11	4.2 2.3–7.6ROR 4.2 · χ² 24 / p 5e-7	3.7 EB05 2.2 · IC025 +0.9 3/3 methods agree	Labeled (related wording) related wording	serious PRR 0.8	no trial data cached
Blood sodium decreased	11	3.9 2.1–7.0ROR 3.9 · χ² 20 / p 3e-6	3.4 EB05 2.1 · IC025 +0.8 3/3 methods agree	Lab value / disease marker	serious PRR 5.0	no trial data cached
Skin disorder	19	3.8 2.4–5.9ROR 3.8 · χ² 36 / p 1e-9	3.5 EB05 2.4 · IC025 +1.0 3/3 methods agree	Labeled (related wording) related wording	serious PRR 2.4	no trial data cached
Product dose omission issue	158	3.7 3.1–4.3ROR 3.8 · χ² 306 / p 7e-69	3.6 EB05 3.2 · IC025 +1.6 3/3 methods agree	Reporting / coding artifact	serious PRR 5.5 · 81% consumer	no trial data cached
Gastroenteritis viral	10	3.6 2.0–6.8ROR 3.6 · χ² 17 / p 2e-5	3.2 EB05 1.9 · IC025 +0.6	Labeled adverse reaction exact term	serious PRR 3.2	no trial data cached
Influenza	61	3.6 2.8–4.6ROR 3.6 · χ² 112 / p 2e-26	3.5 EB05 2.8 · IC025 +1.4 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 5.4	no trial data cached
Skin ulcer	14	3.6 2.1–6.0ROR 3.6 · χ² 23 / p 6e-7	3.3 EB05 2.1 · IC025 +0.8 3/3 methods agree	Not in label — unassessed	serious PRR 4.3	no trial data cached
Viral infection	18	3.6 2.3–5.7ROR 3.6 · χ² 31 / p 1e-8	3.3 EB05 2.2 · IC025 +0.9 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 3.8	no trial data cached
Eating disorder	11	3.4 1.9–6.1ROR 3.4 · χ² 16 / p 3e-5	3.0 EB05 1.8 · IC025 +0.6	Not in label — unassessed	serious PRR 3.0	no trial data cached
Blood pressure abnormal	10	3.3 1.8–6.2ROR 3.3 · χ² 14 / p 9e-5	3.0 EB05 1.8 · IC025 +0.5	Lab value / disease marker	serious PRR 3.9	no trial data cached
Red blood cell count decreased	14	3.2 1.9–5.4ROR 3.2 · χ² 19 / p 6e-6	3.0 EB05 1.9 · IC025 +0.7	Lab value / disease marker	serious PRR 3.5	no trial data cached
Drug ineffective for unapproved indication	27	3.2 2.2–4.6ROR 3.2 · χ² 39 / p 3e-10	3.1 EB05 2.2 · IC025 +1.0 3/3 methods agree	Reporting / coding artifact	serious PRR 5.8 · 93% clinician	no trial data cached
Clostridium difficile infection	10	3.0 1.6–5.6ROR 3.0 · χ² 12 / p 3e-4	2.8 EB05 1.6 · IC025 +0.4	Labeled (related wording) related wording	serious PRR 3.7	no trial data cached
Covid-19	81	3.0 2.4–3.7ROR 3.1 · χ² 108 / p 1e-25	3.0 EB05 2.5 · IC025 +1.2 3/3 methods agree	Not in label — unassessed	serious PRR 3.6	no trial data cached
Osteonecrosis (bone death)	14	2.8 1.6–4.7ROR 2.8 · χ² 14 / p 8e-5	2.6 EB05 1.7 · IC025 +0.5	Not in label — unassessed	serious PRR 3.2	no trial data cached
Limb discomfort	13	2.8 1.6–4.8ROR 2.8 · χ² 13 / p 2e-4	2.6 EB05 1.6 · IC025 +0.4	Labeled adverse reaction exact term	serious PRR 3.7	no trial data cached
Bone pain	23	2.6 1.7–3.9ROR 2.6 · χ² 21 / p 3e-6	2.5 EB05 1.8 · IC025 +0.6	Not in label — unassessed	serious PRR 1.4	no trial data cached
Illness	37	2.4 1.8–3.3ROR 2.4 · χ² 30 / p 2e-8	2.4 EB05 1.8 · IC025 +0.7	Reporting / coding artifact	serious PRR 2.7 · ♀ 75% (drug 47%)	no trial data cached
Eye disorder	12	2.4 1.4–4.2ROR 2.4 · χ² 9 / p 0.002	2.3 EB05 1.4 · IC025 +0.2	Not in label — unassessed	serious PRR 2.8	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 use in unapproved indication	454	12.3 11.3–13.4ROR 14.1 · χ² 4,732 / p <1e-300	12.2 EB05 11.3 · IC025 +3.4 3/3 methods agree	Reporting / coding artifact	serious PRR 16.8	no trial data cached
Inappropriate schedule of product administration	440	16.4 15.1–17.9ROR 18.9 · χ² 6,400 / p <1e-300	16.4 EB05 15.1 · IC025 +3.9 3/3 methods agree	Reporting / coding artifact	serious PRR 25.2	no trial data cached
Product dose omission issue	158	3.7 3.1–4.3ROR 3.8 · χ² 306 / p 7e-69	3.6 EB05 3.2 · IC025 +1.6 3/3 methods agree	Reporting / coding artifact	serious PRR 5.5 · 81% consumer	no trial data cached
Hospitalisation	145	6.3 5.4–7.4ROR 6.5 · χ² 642 / p 7e-142	6.2 EB05 5.4 · IC025 +2.3 3/3 methods agree	Reporting / coding artifact	serious PRR 7.3	no trial data cached
Covid-19	81	3.0 2.4–3.7ROR 3.1 · χ² 108 / p 1e-25	3.0 EB05 2.5 · IC025 +1.2 3/3 methods agree	Not in label — unassessed	serious PRR 3.6	no trial data cached
Disease progression	77	4.3 3.5–5.4ROR 4.4 · χ² 193 / p 4e-44	4.2 EB05 3.5 · IC025 +1.7 3/3 methods agree	Reporting / coding artifact	serious PRR 4.8	no trial data cached
Influenza	61	3.6 2.8–4.6ROR 3.6 · χ² 112 / p 2e-26	3.5 EB05 2.8 · IC025 +1.4 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 5.4	no trial data cached
Dry eye	54	7.3 5.6–9.6ROR 7.5 · χ² 290 / p 2e-65	7.0 EB05 5.5 · IC025 +2.3 3/3 methods agree	Not in label — unassessed	serious PRR 8.1	no trial data cached
Hepatic enzyme increased	45	4.4 3.3–5.8ROR 4.4 · χ² 114 / p 8e-27	4.2 EB05 3.3 · IC025 +1.6 3/3 methods agree	Lab value / disease marker	serious PRR 2.7	no trial data cached
Depressed mood	40	5.0 3.7–6.8ROR 5.1 · χ² 125 / p 3e-29	4.7 EB05 3.6 · IC025 +1.7 3/3 methods agree	Not in label — unassessed	serious PRR 3.3	no trial data cached
Illness	37	2.4 1.8–3.3ROR 2.4 · χ² 30 / p 2e-8	2.4 EB05 1.8 · IC025 +0.7	Reporting / coding artifact	serious PRR 2.7 · ♀ 75% (drug 47%)	no trial data cached
Loss of personal independence in daily activities	31	4.3 3.0–6.1ROR 4.3 · χ² 75 / p 2e-18	4.1 EB05 3.0 · IC025 +1.4 3/3 methods agree	Not in label — unassessed	serious PRR 3.4	no trial data cached
Product dose omission in error	30	7.4 5.2–10.5ROR 7.4 · χ² 159 / p 1e-36	6.7 EB05 4.9 · IC025 +2.1 3/3 methods agree	Reporting / coding artifact	serious PRR 5.6	no trial data cached
Drug ineffective for unapproved indication	27	3.2 2.2–4.6ROR 3.2 · χ² 39 / p 3e-10	3.1 EB05 2.2 · IC025 +1.0 3/3 methods agree	Reporting / coding artifact	serious PRR 5.8 · 93% clinician	no trial data cached
Emotional disorder	26	5.5 3.8–8.1ROR 5.6 · χ² 92 / p 4e-22	5.1 EB05 3.6 · IC025 +1.7 3/3 methods agree	Not in label — unassessed	serious PRR 5.8	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.

Dry eye — n=54, PRR 7.3
Emotional disorder — n=26, PRR 5.5
Depressed mood — n=40, PRR 5.0
Loss of personal independence in daily activities — n=31, PRR 4.3
Covid-19 — n=81, PRR 3.0
Bone pain — n=23, PRR 2.6

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 Belumosudil?

In FDA FAERS, the most frequently co-reported reaction terms for Belumosudil are covid-19, influenza, dry eye, hepatic enzyme increased, depressed mood, loss of personal independence in daily activities. 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 Belumosudil have an FDA boxed warning?

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

Do FAERS signals prove that Belumosudil 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 102e4ef4-7f84-4e34-8df1-479c24d1575d, effective 20260407; matched on openfda.generic_name.exact:"BELUMOSUDIL")
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, 73 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.