Avalglucosidase Alfa-Ngpt side effects: what 914 FDA adverse event reports show

Avalglucosidase Alfa-Ngpt · Nexviazyme · 11 reaction terms · 70 drug–reaction co-reports · data 2026-09-14

Drug class

Hydrolytic Lysosomal Glycogen-specific Enzyme

FDA label (Established Pharmacologic Class)

Brand names

Nexviazyme

openFDA label

Who reports

914 reports · 20% serious · 7 with death outcome · 55% female

openFDA FAERS counts, all years, deduplication not applied

Used for

NEXVIAZYME is indicated for the treatment of patients 1 year of age and older with late-onset Pompe disease (lysosomal acid alpha-glucosidase [GAA] deficiency). NEXVIAZYME is a hydrolytic lysosomal glycogen-specific enzyme indicated for the treatment of patients 1 year of age and older with late-onset Pompe disease (lysosomal acid alpha-glucosidase [GAA] deficiency). ( 1 )

FDA label, Indications and Usage

What it is

Avalglucosidase alfa-ngpt is a hydrolytic lysosomal glycogen-specific recombinant human α-glucosidase enzyme conjugated with multiple synthetic bis-mannose-6-phosphate (bis-M6P)-tetra-mannose .

FDA label, Description section

Boxed warning

SEVERE HYPERSENSITIVITY REACTIONS, INFUSION-ASSOCIATED REACTIONS, and RISK OF ACUTE CARDIORESPIRATORY FAILURE IN SUSCEPTIBLE PATIENTS WARNING: SEVERE HYPERSENSITIVITY REACTIONS, INFUSION-ASSOCIATED REACTIONS, and RISK OF ACUTE CARDIORESPIRATORY FAILURE IN SUSCEPTIBLE PATIENTS See full prescribing information for complete boxed warning.

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 5 strongest signals

Reporting / coding artifact 1Not in label — unassessed 4

What the badges mean

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. 6 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
Product preparation error	21	23.3 15.3–35.5ROR 23.8 · χ² 426 / p 6e-95	22.8 EB05 15.7 · IC025 +3.2 3/3 methods agree	Reporting / coding artifact	serious n=1	no trial data cached
Poor venous access	10	22.2 12.0–41.2ROR 22.5 · χ² 182 / p 8e-42	21.0 EB05 11.6 · IC025 +2.4 3/3 methods agree	Not in label — unassessed	serious n=2	no trial data cached
Weight fluctuation	5	11.0 4.6–26.4ROR 11.1 · χ² 36 / p 1e-9	7.1 EB05 2.9 · IC025 +1.0 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Pharyngitis streptococcal	5	10.6 4.4–25.4ROR 10.7 · χ² 34 / p 2e-9	6.8 EB05 2.8 · IC025 +0.9 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Respiratory tract congestion	7	10.1 4.8–21.1ROR 10.2 · χ² 49 / p 2e-12	7.2 EB05 3.4 · IC025 +1.3 3/3 methods agree	Not in label — unassessed	serious PRR 9.4	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 preparation error	21	23.3 15.3–35.5ROR 23.8 · χ² 426 / p 6e-95	22.8 EB05 15.7 · IC025 +3.2 3/3 methods agree	Reporting / coding artifact	serious n=1	no trial data cached
Poor venous access	10	22.2 12.0–41.2ROR 22.5 · χ² 182 / p 8e-42	21.0 EB05 11.6 · IC025 +2.4 3/3 methods agree	Not in label — unassessed	serious n=2	no trial data cached
Respiratory tract congestion	7	10.1 4.8–21.1ROR 10.2 · χ² 49 / p 2e-12	7.2 EB05 3.4 · IC025 +1.3 3/3 methods agree	Not in label — unassessed	serious PRR 9.4	no trial data cached
Pharyngitis streptococcal	5	10.6 4.4–25.4ROR 10.7 · χ² 34 / p 2e-9	6.8 EB05 2.8 · IC025 +0.9 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Weight fluctuation	5	11.0 4.6–26.4ROR 11.1 · χ² 36 / p 1e-9	7.1 EB05 2.9 · IC025 +1.0 3/3 methods agree	Not in label — unassessed	–	no trial data cached
Breast cancer female	4	3.4 1.3–9.1ROR 3.4 · χ² 5 / p 0.016	2.7 EB05 1.2 · IC025 -0.3 PRR-only: not supported by EBGM or IC	Not in label — unassessed	serious PRR 9.7	no trial data cached
Incorrect product administration duration	4	4.5 1.7–12.0ROR 4.5 · χ² 8 / p 0.003	3.2 EB05 1.4 · IC025 -0.1 PRR-only: not supported by EBGM or IC	Reporting / coding artifact	serious n=1	no trial data cached
Intercepted product preparation error	4	7.5 2.8–20.0ROR 7.6 · χ² 17 / p 2e-5	4.6 EB05 1.9 · IC025 +0.4	Not in label — unassessed	–	no trial data cached
Pharyngeal swelling	4	9.6 3.6–25.5ROR 9.6 · χ² 23 / p 9e-7	5.6 EB05 2.2 · IC025 +0.5 3/3 methods agree	Not in label — unassessed	serious n=1	no trial data cached
Pancreatic carcinoma	3	2.4 0.8–7.3ROR 2.4 · χ² 1 / p 0.136	2.0 EB05 0.8 · IC025 -1.1 PRR-only: not supported by EBGM or IC	Not in label — unassessed	serious PRR 6.7	no trial data cached
Exposure via skin contact	3	3.0 1.0–9.4ROR 3.1 · χ² 2 / p 0.064	2.4 EB05 1.0 · IC025 -0.8 PRR-only: not supported by EBGM or IC	Reporting / coding artifact	serious n=1	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.

✓ A hand-written Bradford Hill causality assessment exists for this drug: Erythropoiesis-stimulating agents (darbepoetin alfa) ↔ Mortality / cardiovascular risk.

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 Avalglucosidase Alfa-Ngpt?

In FDA FAERS, the most frequently co-reported reaction terms for Avalglucosidase Alfa-Ngpt are poor venous access, respiratory tract congestion, pharyngitis streptococcal, weight fluctuation, breast cancer female, intercepted product preparation error. 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 Avalglucosidase Alfa-Ngpt have an FDA boxed warning?

Yes. The current FDA label carries a boxed warning: SEVERE HYPERSENSITIVITY REACTIONS, INFUSION-ASSOCIATED REACTIONS, and RISK OF ACUTE CARDIORESPIRATORY FAILURE IN SUSCEPTIBLE PATIENTS WARNING: SEVERE HYPERSENSITIVITY REACTIONS, INFUSION-ASSOCIATED REACTIONS, and RISK OF ACUTE CARDIORESPIRATORY FAILURE IN SUSCEPTIBLE PATIENTS See full prescribing information for complete boxed warning.

Do FAERS signals prove that Avalglucosidase Alfa-Ngpt 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 80eb3c9c-01d3-44fe-90ef-81df101b954d, effective 20250605; matched on openfda.generic_name.exact:"AVALGLUCOSIDASE ALFA-NGPT")
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, 11 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.