Iptacopan side effects: what 730 FDA adverse event reports show

Iptacopan · Fabhalta · 10 reaction terms · 79 drug–reaction co-reports · data 2026-09-14

Drug class

Complement factor b inhibitor

FDA label, Indications wording

Brand names

Fabhalta

openFDA label

Who reports

730 reports · 47% serious · 44 with death outcome · 53% female

openFDA FAERS counts, all years, deduplication not applied

Used for

FABHALTA is a complement factor B inhibitor, indicated for: the treatment of adults with paroxysmal nocturnal hemoglobinuria (PNH). ( 1.1 ) slowing kidney function decline in adults with primary immunoglobulin A nephropathy (IgAN) at risk of disease progression. ( 1.2 ) the treatment of adults with complement 3 glomerulopathy (C3G), to reduce proteinuria.

FDA label, Indications and Usage

What it is

FABHALTA contains iptacopan, a complement Factor B inhibitor.

FDA label, Description section

Boxed warning

SERIOUS INFECTIONS CAUSED BY ENCAPSULATED BACTERIA FABHALTA, a complement inhibitor, increases the risk of serious infections, especially those caused by encapsulated bacteria, such as Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b [see Warnings and Precautions (5.1)] .

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 8 strongest signals

Likely indication confounding 1Lab value / disease marker 4Not in label — unassessed 3

What the badges mean

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.
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. 2 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
Glomerular filtration rate decreased	11	26.1 14.5–46.9ROR 26.5 · χ² 241 / p 1e-54	25.0 EB05 14.6 · IC025 +2.6 3/3 methods agree	Lab value / disease marker	serious PRR 28.9	no trial data cached
Proteinuria	13	19.8 11.6–34.0ROR 20.2 · χ² 214 / p 1e-48	19.0 EB05 11.4 · IC025 +2.6 3/3 methods agree	Likely indication confounding term in indications	serious PRR 16.8	no trial data cached
Blood urine present	12	18.1 10.3–31.7ROR 18.4 · χ² 177 / p 1e-40	17.1 EB05 9.7 · IC025 +2.4 3/3 methods agree	Lab value / disease marker	serious PRR 23.8	no trial data cached
Blood lactate dehydrogenase increased	9	16.2 8.5–31.1ROR 16.4 · χ² 114 / p 7e-27	14.4 EB05 6.8 · IC025 +2.0 3/3 methods agree	Lab value / disease marker	serious PRR 14.2	no trial data cached
Chromaturia	11	14.0 7.8–25.2ROR 14.2 · χ² 120 / p 3e-28	12.4 EB05 6.4 · IC025 +2.1 3/3 methods agree	Not in label — unassessed	serious PRR 19.8	no trial data cached
Brain fog	7	13.8 6.6–28.8ROR 13.9 · χ² 71 / p 2e-17	10.8 EB05 4.6 · IC025 +1.6 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Full blood count abnormal	5	13.6 5.7–32.6ROR 13.7 · χ² 47 / p 4e-12	9.2 EB05 3.4 · IC025 +1.1 3/3 methods agree	Lab value / disease marker	serious PRR 8.9	no trial data cached
Myelodysplastic syndrome	5	9.9 4.1–23.8ROR 10.0 · χ² 32 / p 9e-9	6.3 EB05 2.7 · IC025 +0.9 3/3 methods agree	Not in label — unassessed	serious PRR 12.3	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
Proteinuria	13	19.8 11.6–34.0ROR 20.2 · χ² 214 / p 1e-48	19.0 EB05 11.4 · IC025 +2.6 3/3 methods agree	Likely indication confounding term in indications	serious PRR 16.8	no trial data cached
Blood urine present	12	18.1 10.3–31.7ROR 18.4 · χ² 177 / p 1e-40	17.1 EB05 9.7 · IC025 +2.4 3/3 methods agree	Lab value / disease marker	serious PRR 23.8	no trial data cached
Chromaturia	11	14.0 7.8–25.2ROR 14.2 · χ² 120 / p 3e-28	12.4 EB05 6.4 · IC025 +2.1 3/3 methods agree	Not in label — unassessed	serious PRR 19.8	no trial data cached
Glomerular filtration rate decreased	11	26.1 14.5–46.9ROR 26.5 · χ² 241 / p 1e-54	25.0 EB05 14.6 · IC025 +2.6 3/3 methods agree	Lab value / disease marker	serious PRR 28.9	no trial data cached
Blood lactate dehydrogenase increased	9	16.2 8.5–31.1ROR 16.4 · χ² 114 / p 7e-27	14.4 EB05 6.8 · IC025 +2.0 3/3 methods agree	Lab value / disease marker	serious PRR 14.2	no trial data cached
Brain fog	7	13.8 6.6–28.8ROR 13.9 · χ² 71 / p 2e-17	10.8 EB05 4.6 · IC025 +1.6 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Myelodysplastic syndrome	5	9.9 4.1–23.8ROR 10.0 · χ² 32 / p 9e-9	6.3 EB05 2.7 · IC025 +0.9 3/3 methods agree	Not in label — unassessed	serious PRR 12.3	no trial data cached
Full blood count abnormal	5	13.6 5.7–32.6ROR 13.7 · χ² 47 / p 4e-12	9.2 EB05 3.4 · IC025 +1.1 3/3 methods agree	Lab value / disease marker	serious PRR 8.9	no trial data cached
Pneumocystis jirovecii pneumonia	3	8.6 2.8–26.7ROR 8.7 · χ² 13 / p 1e-4	4.5 EB05 1.7 · IC025 -0.0 PRR-only: not supported by EBGM or IC	Not in label — unassessed	serious PRR 10.6	no trial data cached
Decreased immune responsiveness	3	8.8 2.9–27.3ROR 8.9 · χ² 14 / p 1e-4	4.6 EB05 1.7 · IC025 -0.0 PRR-only: not supported by EBGM or IC	Not in label — unassessed	serious PRR 9.0	no trial data cached

Unlabeled candidate signals

Every screened signal with n ≥ 20 was either labeled, an indication term, or an artifact pattern — no unlabeled candidate stood out in the top signals.

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 Iptacopan?

In FDA FAERS, the most frequently co-reported reaction terms for Iptacopan are proteinuria, blood urine present, chromaturia, glomerular filtration rate decreased, blood lactate dehydrogenase increased, brain fog. 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 Iptacopan have an FDA boxed warning?

Yes. The current FDA label carries a boxed warning: SERIOUS INFECTIONS CAUSED BY ENCAPSULATED BACTERIA FABHALTA, a complement inhibitor, increases the risk of serious infections, especially those caused by encapsulated bacteria, such as Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae type b [see Warnings and Precautions (5.1)] .

Do FAERS signals prove that Iptacopan 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 a76b5845-6e21-4d3b-ad07-cd8df1b60bee, effective 20260716; matched on openfda.generic_name.exact:"IPTACOPAN")
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, 10 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.