Ublituximab side effects: what 3,775 FDA adverse event reports show

Ublituximab · Briumvi · 49 reaction terms · 2,644 drug–reaction co-reports · data 2026-09-14

Drug class

CD20-directed Cytolytic Antibody

FDA label (Established Pharmacologic Class) · compare the class

Brand names

Briumvi

openFDA label

Who reports

3,775 reports · 22% serious · 62 with death outcome · 74% female

openFDA FAERS counts, all years, deduplication not applied

Used for

BRIUMVI is indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults. BRIUMVI is a CD20-directed cytolytic antibo.

FDA label, Indications and Usage

What it is

Ublituximab-xiiy is a recombinant chimeric monoclonal IgG1 antibody with reduced fucose content directed against CD20-expressing B-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 24 strongest signals

Labeled adverse reaction 6Labeled (related wording) 5Likely indication confounding 1Reporting / coding artifact 6Lab value / disease marker 1Not 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.
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.
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. 25 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
Infusion related reaction (reaction during infusion)	1,412	121.1 116.2–126.3ROR 192.8 · χ² 165,009 / p <1e-300	118.4 EB05 113.3 · IC025 +6.7 3/3 methods agree	Labeled (related wording) related wording	serious PRR 40.0 · 72% consumer	no trial data cached
Brain fog	32	12.2 8.6–17.2ROR 12.3 · χ² 317 / p 3e-71	11.7 EB05 8.4 · IC025 +2.8 3/3 methods agree	Labeled (related wording) related wording	serious PRR 7.6 · 94% consumer	no trial data cached
Drug effect less than expected	22	8.7 5.7–13.1ROR 8.7 · χ² 141 / p 6e-33	7.7 EB05 5.2 · IC025 +2.2 3/3 methods agree	Reporting / coding artifact	serious n=1 · 95% consumer	no trial data cached
Multiple sclerosis	75	8.7 6.9–10.8ROR 8.8 · χ² 501 / p 3e-111	8.4 EB05 6.9 · IC025 +2.7 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 13.5 · 76% consumer	no trial data cached
Covid-19 pneumonia	18	8.4 5.3–13.3ROR 8.4 · χ² 110 / p 5e-26	7.3 EB05 4.7 · IC025 +2.0 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 22.2	no trial data cached
Multiple sclerosis relapse	94	7.6 6.2–9.2ROR 7.7 · χ² 529 / p 3e-117	7.3 EB05 6.1 · IC025 +2.5 3/3 methods agree	Labeled (related wording) related wording	serious PRR 12.8 · 86% consumer	no trial data cached
Oral herpes	19	5.4 3.5–8.5ROR 5.4 · χ² 64 / p 6e-16	4.8 EB05 3.3 · IC025 +1.5 3/3 methods agree	Not in label — unassessed	serious PRR 1.7	no trial data cached
Illness	97	5.4 4.4–6.5ROR 5.5 · χ² 341 / p 2e-76	5.2 EB05 4.4 · IC025 +2.1 3/3 methods agree	Reporting / coding artifact	serious PRR 4.3 · 85% consumer	no trial data cached
Upper respiratory tract infection (cold/sinus infection)	42	5.1 3.7–6.8ROR 5.1 · χ² 133 / p 6e-31	4.8 EB05 3.7 · IC025 +1.8 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 6.9	no trial data cached
Maternal exposure during pregnancy	80	5.0 4.1–6.3ROR 5.1 · χ² 255 / p 9e-58	4.9 EB05 4.1 · IC025 +1.9 3/3 methods agree	Reporting / coding artifact	serious PRR 2.9	no trial data cached
Therapeutic response shortened	25	4.4 2.9–6.4ROR 4.4 · χ² 61 / p 2e-15	4.1 EB05 2.9 · IC025 +1.4 3/3 methods agree	Reporting / coding artifact	serious PRR 1.3 · 88% consumer	no trial data cached
Blood test abnormal	11	4.3 2.4–7.8ROR 4.4 · χ² 25 / p 3e-7	3.7 EB05 2.3 · IC025 +0.9 3/3 methods agree	Reporting / coding artifact	serious PRR 3.2	no trial data cached
Immunodeficiency	10	3.8 2.0–7.0ROR 3.8 · χ² 18 / p 1e-5	3.3 EB05 1.9 · IC025 +0.7	Not in label — unassessed	serious PRR 8.5	no trial data cached
Respiratory tract infection	17	3.6 2.3–5.8ROR 3.6 · χ² 30 / p 2e-8	3.4 EB05 2.2 · IC025 +0.9 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 4.1	no trial data cached
Lymphocyte count decreased	11	3.5 1.9–6.2ROR 3.5 · χ² 17 / p 2e-5	3.1 EB05 1.9 · IC025 +0.6	Lab value / disease marker	serious PRR 1.0	no trial data cached
Urinary tract infection (bladder infection)	99	3.2 2.7–3.9ROR 3.3 · χ² 151 / p 4e-35	3.2 EB05 2.7 · IC025 +1.3 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 4.3	no trial data cached
Inappropriate schedule of product administration	88	2.8 2.2–3.4ROR 2.8 · χ² 98 / p 2e-23	2.7 EB05 2.3 · IC025 +1.1 3/3 methods agree	Reporting / coding artifact	serious PRR 0.4 · 75% consumer	no trial data cached
Balance disorder	43	2.8 2.0–3.7ROR 2.8 · χ² 47 / p 5e-12	2.7 EB05 2.1 · IC025 +0.9 3/3 methods agree	Not in label — unassessed	serious PRR 1.9 · 91% consumer	no trial data cached
Herpes zoster (shingles)	28	2.7 1.9–3.9ROR 2.7 · χ² 28 / p 5e-8	2.6 EB05 1.9 · IC025 +0.8	Not in label — unassessed	serious PRR 2.0	no trial data cached
Cognitive disorder	21	2.5 1.6–3.8ROR 2.5 · χ² 18 / p 1e-5	2.4 EB05 1.7 · IC025 +0.5	Not in label — unassessed	serious PRR 1.7 · 90% consumer	no trial data cached
Covid-19	73	2.3 1.8–2.9ROR 2.3 · χ² 52 / p 3e-13	2.3 EB05 1.9 · IC025 +0.8	Labeled adverse reaction exact term	serious PRR 2.9 · 79% consumer	no trial data cached
Memory impairment	56	2.3 1.7–2.9ROR 2.3 · χ² 38 / p 3e-10	2.2 EB05 1.8 · IC025 +0.7	Labeled (related wording) related wording	serious PRR 2.7 · 89% consumer	no trial data cached
Nasopharyngitis (common cold)	75	2.3 1.8–2.8ROR 2.3 · χ² 51 / p 4e-13	2.2 EB05 1.8 · IC025 +0.8	Labeled adverse reaction exact term	serious PRR 1.2 · 92% consumer	no trial data cached
Influenza like illness (flu-like illness)	33	2.2 1.6–3.1ROR 2.2 · χ² 21 / p 2e-6	2.2 EB05 1.6 · IC025 +0.5	Labeled (related wording) related wording	serious PRR 1.5 · 85% consumer	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
Infusion related reaction (reaction during infusion)	1,412	121.1 116.2–126.3ROR 192.8 · χ² 165,009 / p <1e-300	118.4 EB05 113.3 · IC025 +6.7 3/3 methods agree	Labeled (related wording) related wording	serious PRR 40.0 · 72% consumer	no trial data cached
Urinary tract infection (bladder infection)	99	3.2 2.7–3.9ROR 3.3 · χ² 151 / p 4e-35	3.2 EB05 2.7 · IC025 +1.3 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 4.3	no trial data cached
Illness	97	5.4 4.4–6.5ROR 5.5 · χ² 341 / p 2e-76	5.2 EB05 4.4 · IC025 +2.1 3/3 methods agree	Reporting / coding artifact	serious PRR 4.3 · 85% consumer	no trial data cached
Multiple sclerosis relapse	94	7.6 6.2–9.2ROR 7.7 · χ² 529 / p 3e-117	7.3 EB05 6.1 · IC025 +2.5 3/3 methods agree	Labeled (related wording) related wording	serious PRR 12.8 · 86% consumer	no trial data cached
Inappropriate schedule of product administration	88	2.8 2.2–3.4ROR 2.8 · χ² 98 / p 2e-23	2.7 EB05 2.3 · IC025 +1.1 3/3 methods agree	Reporting / coding artifact	serious PRR 0.4 · 75% consumer	no trial data cached
Maternal exposure during pregnancy	80	5.0 4.1–6.3ROR 5.1 · χ² 255 / p 9e-58	4.9 EB05 4.1 · IC025 +1.9 3/3 methods agree	Reporting / coding artifact	serious PRR 2.9	no trial data cached
Nasopharyngitis (common cold)	75	2.3 1.8–2.8ROR 2.3 · χ² 51 / p 4e-13	2.2 EB05 1.8 · IC025 +0.8	Labeled adverse reaction exact term	serious PRR 1.2 · 92% consumer	no trial data cached
Multiple sclerosis	75	8.7 6.9–10.8ROR 8.8 · χ² 501 / p 3e-111	8.4 EB05 6.9 · IC025 +2.7 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 13.5 · 76% consumer	no trial data cached
Covid-19	73	2.3 1.8–2.9ROR 2.3 · χ² 52 / p 3e-13	2.3 EB05 1.9 · IC025 +0.8	Labeled adverse reaction exact term	serious PRR 2.9 · 79% consumer	no trial data cached
Memory impairment	56	2.3 1.7–2.9ROR 2.3 · χ² 38 / p 3e-10	2.2 EB05 1.8 · IC025 +0.7	Labeled (related wording) related wording	serious PRR 2.7 · 89% consumer	no trial data cached
Balance disorder	43	2.8 2.0–3.7ROR 2.8 · χ² 47 / p 5e-12	2.7 EB05 2.1 · IC025 +0.9 3/3 methods agree	Not in label — unassessed	serious PRR 1.9 · 91% consumer	no trial data cached
Upper respiratory tract infection (cold/sinus infection)	42	5.1 3.7–6.8ROR 5.1 · χ² 133 / p 6e-31	4.8 EB05 3.7 · IC025 +1.8 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 6.9	no trial data cached
Influenza like illness (flu-like illness)	33	2.2 1.6–3.1ROR 2.2 · χ² 21 / p 2e-6	2.2 EB05 1.6 · IC025 +0.5	Labeled (related wording) related wording	serious PRR 1.5 · 85% consumer	no trial data cached
Brain fog	32	12.2 8.6–17.2ROR 12.3 · χ² 317 / p 3e-71	11.7 EB05 8.4 · IC025 +2.8 3/3 methods agree	Labeled (related wording) related wording	serious PRR 7.6 · 94% consumer	no trial data cached
Herpes zoster (shingles)	28	2.7 1.9–3.9ROR 2.7 · χ² 28 / p 5e-8	2.6 EB05 1.9 · IC025 +0.8	Not in label — unassessed	serious PRR 2.0	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.

Balance disorder — n=43, PRR 2.8
Herpes zoster — n=28, PRR 2.7
Cognitive disorder — n=21, PRR 2.5

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 Ublituximab?

In FDA FAERS, the most frequently co-reported reaction terms for Ublituximab are infusion related reaction, urinary tract infection, multiple sclerosis relapse, nasopharyngitis, multiple sclerosis, covid-19. 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 Ublituximab have an FDA boxed warning?

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

Do FAERS signals prove that Ublituximab 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 3a77cd8c-811b-407c-9140-d0c5c26435c2, effective 20260219; matched on openfda.generic_name.exact:"UBLITUXIMAB")
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, 49 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.