Pegvaliase-Pqpz side effects: what 8,137 FDA adverse event reports show
Drug class
Phenylalanine Metabolizing Enzyme
Brand names
Palynziq
Who reports
8,137 reports · 16% serious · 12 with death outcome · 61% female
Used for
PALYNZIQ is indicated to reduce blood phenylalanine concentrations in adult and pediatric patients 12 years of age and older with phenylketonuria (PKU) who have uncontrolled blood phenylalanine concentrations greater than 600 micromol/L on existing management.
What it is
Pegvaliase-pqpz is a phenylalanine-metabolizing enzyme that is composed of recombinant phenylalanine ammonia lyase (rAvPAL) conjugated to N-hydroxysuccinimide (NHS)-methoxypolyethylene glycol (PEG).
Boxed warning
ANAPHYLAXIS Anaphylaxis has been reported after administration of PALYNZIQ and may occur at any time during treatment [see Warnings and Precautions (5.1) ] . Administer the initial dose of PALYNZIQ under the supervision of a healthcare provider equipped to manage anaphylaxis, and closely observe patients for at least 60 minutes following injection.
Causality screen of the 40 strongest signals
What the badges mean
- Labeled — boxed warning The term (or its clinical synonym) appears in the FDA boxed warning: causality is regulator-recognised and considered serious.
- 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. 442 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Hyperphenylalaninaemia | 10 | 8,442.3 2,323.8–30,670.6ROR 8,452.7 · χ² 17,578 / p <1e-300 | 411.2 EB05 238.7 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious n=1 | no trial data cached |
| Amino acid level decreased | 198 | 4,011.8 3,210.4–5,013.3ROR 4,111.4 · χ² 305,706 / p <1e-300 | 1,348.7 EB05 1,198.3 · IC025 +8.1 3/3 methods agree | Lab value / disease marker | serious n=11 · 76% consumer | no trial data cached |
| Amino acid level abnormal | 32 | 1,286.4 841.1–1,967.6ROR 1,291.5 · χ² 26,411 / p <1e-300 | 564.0 EB05 418.2 · IC025 +5.3 3/3 methods agree | Lab value / disease marker | serious n=2 | no trial data cached |
| Amino acid level increased | 136 | 589.8 490.0–709.9ROR 599.8 · χ² 64,367 / p <1e-300 | 448.3 EB05 388.5 · IC025 +7.2 3/3 methods agree | Lab value / disease marker | serious n=15 · 71% consumer | no trial data cached |
| Needle fatigue | 14 | 81.0 47.6–137.8ROR 81.1 · χ² 995 / p 1e-218 | 71.2 EB05 45.1 · IC025 +3.5 3/3 methods agree | Not in label — unassessed | – | no trial data cached |
| Injection site scar | 42 | 38.8 28.7–52.6ROR 39.0 · χ² 1,488 / p <1e-300 | 37.7 EB05 29.0 · IC025 +4.2 3/3 methods agree | Labeled (related wording) related wording | 79% consumer | no trial data cached |
| Injection site reaction | 908 | 34.4 32.4–36.6ROR 38.6 · χ² 29,131 / p <1e-300 | 34.0 EB05 32.1 · IC025 +5.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 19.0 · 89% consumer | no trial data cached |
| Injection site oedema | 17 | 25.8 16.0–41.6ROR 25.9 · χ² 377 / p 2e-84 | 24.9 EB05 16.4 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | – | no trial data cached |
| Injection site induration | 95 | 18.9 15.5–23.2ROR 19.2 · χ² 1,586 / p <1e-300 | 18.8 EB05 15.8 · IC025 +3.8 3/3 methods agree | Labeled (related wording) related wording | serious n=10 · 72% consumer | no trial data cached |
| Injection site swelling | 554 | 18.9 17.4–20.5ROR 20.2 · χ² 9,341 / p <1e-300 | 18.8 EB05 17.5 · IC025 +4.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 27.1 · 85% consumer | no trial data cached |
| Injection site rash | 212 | 18.1 15.8–20.6ROR 18.5 · χ² 3,379 / p <1e-300 | 17.9 EB05 16.0 · IC025 +3.9 3/3 methods agree | Labeled (related wording) related wording | serious n=11 · 76% consumer | no trial data cached |
| Pharyngeal paraesthesia | 10 | 16.6 8.9–30.8ROR 16.6 · χ² 130 / p 2e-30 | 15.0 EB05 7.5 · IC025 +2.2 3/3 methods agree | Labeled (related wording) related wording | serious n=6 | no trial data cached |
| Injection site erythema (redness where injected) | 750 | 15.7 14.7–16.8ROR 17.2 · χ² 10,298 / p <1e-300 | 15.6 EB05 14.7 · IC025 +3.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 16.7 · 86% consumer | no trial data cached |
| Anaphylactic reaction (severe allergic reaction) | 327 | 15.4 13.8–17.1ROR 16.0 · χ² 4,364 / p <1e-300 | 15.3 EB05 13.9 · IC025 +3.7 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 56.2 | no trial data cached |
| Injection site pruritus | 363 | 14.1 12.7–15.6ROR 14.7 · χ² 4,386 / p <1e-300 | 14.0 EB05 12.8 · IC025 +3.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 12.9 · 87% consumer | no trial data cached |
| Pharyngeal swelling | 50 | 13.5 10.2–17.8ROR 13.6 · χ² 562 / p 1e-124 | 13.2 EB05 10.3 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | serious n=43 · ♀ 82% (drug 61%) | no trial data cached |
| Throat tightness | 141 | 13.5 11.4–15.9ROR 13.7 · χ² 1,608 / p <1e-300 | 13.3 EB05 11.6 · IC025 +3.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 59.0 | no trial data cached |
| Injection site papule | 22 | 12.5 8.3–19.1ROR 12.6 · χ² 221 / p 2e-50 | 11.8 EB05 7.8 · IC025 +2.6 3/3 methods agree | Labeled (related wording) related wording | 86% consumer | no trial data cached |
| Injection site warmth | 91 | 11.4 9.3–14.0ROR 11.5 · χ² 849 / p 6e-187 | 11.2 EB05 9.3 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | serious n=7 · 85% consumer | no trial data cached |
| Injection site urticaria | 94 | 10.0 8.2–12.2ROR 10.1 · χ² 749 / p 4e-165 | 9.7 EB05 8.2 · IC025 +2.9 3/3 methods agree | Labeled (related wording) related wording | serious n=10 · 73% consumer | no trial data cached |
| Injection site hypersensitivity | 11 | 9.2 5.1–16.7ROR 9.2 · χ² 72 / p 9e-18 | 7.4 EB05 4.1 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | – | no trial data cached |
| Arthralgia (joint pain) | 1,395 | 8.7 8.3–9.1ROR 10.3 · χ² 9,616 / p <1e-300 | 8.6 EB05 8.3 · IC025 +3.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.8 · 82% consumer | no trial data cached |
| Injection site inflammation | 16 | 8.3 5.1–13.6ROR 8.3 · χ² 96 / p 6e-23 | 7.1 EB05 4.5 · IC025 +1.9 3/3 methods agree | Labeled (related wording) related wording | serious n=5 | no trial data cached |
| Urticaria (hives) | 497 | 7.7 7.1–8.4ROR 8.1 · χ² 2,899 / p <1e-300 | 7.6 EB05 7.1 · IC025 +2.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 13.0 · 74% consumer | no trial data cached |
| Injection site irritation | 36 | 7.3 5.3–10.2ROR 7.4 · χ² 190 / p 2e-43 | 6.8 EB05 5.1 · IC025 +2.2 3/3 methods agree | Labeled (related wording) related wording | serious n=3 · 78% consumer | no trial data cached |
| Injection site bruising | 214 | 7.0 6.1–8.0ROR 7.1 · χ² 1,092 / p 7e-240 | 6.9 EB05 6.1 · IC025 +2.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 7.2 · 80% consumer | no trial data cached |
| Sars-cov-2 test positive | 34 | 6.5 4.7–9.2ROR 6.6 · χ² 154 / p 1e-35 | 6.1 EB05 4.5 · IC025 +2.0 3/3 methods agree | Lab value / disease marker | 79% consumer | no trial data cached |
| Maternal exposure during pregnancy | 213 | 6.2 5.4–7.1ROR 6.4 · χ² 928 / p 4e-204 | 6.1 EB05 5.5 · IC025 +2.4 3/3 methods agree | Reporting / coding artifact | serious PRR 7.0 · ♀ 100% (drug 61%) | no trial data cached |
| Attention deficit hyperactivity disorder | 10 | 6.2 –ROR 6.2 · χ² – | – | Not in label — unassessed | serious n=1 | no trial data cached |
| Paraesthesia oral | 34 | 6.1 4.3–8.5ROR 6.1 · χ² 139 / p 2e-32 | 5.6 EB05 4.2 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 27.8 | no trial data cached |
| Sensation of foreign body | 19 | 5.8 3.7–9.1ROR 5.8 · χ² 71 / p 2e-17 | 5.2 EB05 3.5 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | serious n=12 | no trial data cached |
| Skin reaction | 26 | 4.8 3.2–7.0ROR 4.8 · χ² 73 / p 6e-18 | 4.4 EB05 3.2 · IC025 +1.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.3 · 77% consumer | no trial data cached |
| Seasonal allergy | 26 | 4.7 3.2–7.0ROR 4.7 · χ² 73 / p 7e-18 | 4.4 EB05 3.2 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious n=1 · 92% consumer | no trial data cached |
| Hypersensitivity (allergic reaction) | 336 | 4.7 4.2–5.2ROR 4.8 · χ² 969 / p 4e-213 | 4.6 EB05 4.2 · IC025 +2.0 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 11.6 · 73% consumer | no trial data cached |
| Swelling of eyelid | 11 | 4.6 2.6–8.4ROR 4.6 · χ² 28 / p 7e-8 | 3.9 EB05 2.4 · IC025 +1.0 3/3 methods agree | Labeled (related wording) related wording | serious n=6 | no trial data cached |
| Injection site discomfort | 17 | 4.2 2.6–6.8ROR 4.2 · χ² 39 / p 2e-10 | 3.8 EB05 2.6 · IC025 +1.1 3/3 methods agree | Labeled (related wording) related wording | serious n=1 | no trial data cached |
| Chest discomfort | 163 | 4.1 3.5–4.8ROR 4.2 · χ² 382 / p 3e-85 | 4.1 EB05 3.6 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 13.7 · 71% consumer | no trial data cached |
| Injection site mass | 57 | 4.0 3.1–5.1ROR 4.0 · χ² 124 / p 4e-29 | 3.9 EB05 3.1 · IC025 +1.5 3/3 methods agree | Labeled (related wording) related wording | serious PRR 1.3 · 89% consumer | no trial data cached |
| Scar | 25 | 3.7 2.5–5.5ROR 3.8 · χ² 48 / p 3e-12 | 3.5 EB05 2.5 · IC025 +1.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 1.7 · 88% consumer | no trial data cached |
| Injection site pain (pain where injected) | 429 | 3.6 3.3–4.0ROR 3.8 · χ² 827 / p 4e-182 | 3.6 EB05 3.3 · IC025 +1.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.9 · 84% consumer | no trial data cached |
Trial evidence (ClinicalTrials.gov)
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 |
|---|---|---|---|---|---|---|
| Arthralgia (joint pain) | 1,395 | 8.7 8.3–9.1ROR 10.3 · χ² 9,616 / p <1e-300 | 8.6 EB05 8.3 · IC025 +3.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.8 · 82% consumer | no trial data cached |
| Injection site reaction | 908 | 34.4 32.4–36.6ROR 38.6 · χ² 29,131 / p <1e-300 | 34.0 EB05 32.1 · IC025 +5.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 19.0 · 89% consumer | no trial data cached |
| Injection site erythema (redness where injected) | 750 | 15.7 14.7–16.8ROR 17.2 · χ² 10,298 / p <1e-300 | 15.6 EB05 14.7 · IC025 +3.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 16.7 · 86% consumer | no trial data cached |
| Injection site swelling | 554 | 18.9 17.4–20.5ROR 20.2 · χ² 9,341 / p <1e-300 | 18.8 EB05 17.5 · IC025 +4.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 27.1 · 85% consumer | no trial data cached |
| Rash | 507 | 3.0 2.8–3.3ROR 3.1 · χ² 690 / p 3e-152 | 3.0 EB05 2.8 · IC025 +1.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.3 · 76% consumer | no trial data cached |
| Urticaria (hives) | 497 | 7.7 7.1–8.4ROR 8.1 · χ² 2,899 / p <1e-300 | 7.6 EB05 7.1 · IC025 +2.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 13.0 · 74% consumer | no trial data cached |
| Headache | 439 | 1.8 1.6–2.0ROR 1.8 · χ² 160 / p 5e-37 | 1.8 EB05 1.7 · IC025 +0.7 | Labeled adverse reaction exact term | serious PRR 1.5 · 82% consumer | no trial data cached |
| Injection site pain (pain where injected) | 429 | 3.6 3.3–4.0ROR 3.8 · χ² 827 / p 4e-182 | 3.6 EB05 3.3 · IC025 +1.7 3/3 methods agree | Labeled (related wording) related wording | serious PRR 4.9 · 84% consumer | no trial data cached |
| Fatigue (tiredness) | 375 | 1.2 1.1–1.4ROR 1.3 · χ² 18 / p 1e-5 | 1.2 EB05 1.1 · IC025 +0.1 | Labeled adverse reaction exact term | serious PRR 0.9 · 79% consumer | no trial data cached |
| Injection site pruritus | 363 | 14.1 12.7–15.6ROR 14.7 · χ² 4,386 / p <1e-300 | 14.0 EB05 12.8 · IC025 +3.6 3/3 methods agree | Labeled (related wording) related wording | serious PRR 12.9 · 87% consumer | no trial data cached |
| Pruritus (itching) | 343 | 2.3 2.1–2.6ROR 2.4 · χ² 264 / p 1e-59 | 2.3 EB05 2.1 · IC025 +1.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.6 · 79% consumer | no trial data cached |
| Hypersensitivity (allergic reaction) | 336 | 4.7 4.2–5.2ROR 4.8 · χ² 969 / p 4e-213 | 4.6 EB05 4.2 · IC025 +2.0 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 11.6 · 73% consumer | no trial data cached |
| Dizziness | 331 | 1.7 1.5–1.9ROR 1.7 · χ² 99 / p 2e-23 | 1.7 EB05 1.6 · IC025 +0.6 | Labeled adverse reaction exact term | serious PRR 4.9 · 72% consumer | no trial data cached |
| Anaphylactic reaction (severe allergic reaction) | 327 | 15.4 13.8–17.1ROR 16.0 · χ² 4,364 / p <1e-300 | 15.3 EB05 13.9 · IC025 +3.7 3/3 methods agree | Labeled — boxed warning synonym match | serious PRR 56.2 | no trial data cached |
| Off label use (used outside approved label) | 320 | 0.9 0.9–1.1ROR 0.9 · χ² 1 / p 0.165 | 0.9 EB05 0.9 · IC025 -0.3 PRR-only: not supported by EBGM or IC | Reporting / coding artifact | serious PRR 1.0 · 78% 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.
- Paraesthesia oral — n=34, PRR 6.1
- Seasonal allergy — n=26, PRR 4.7
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 Pegvaliase-Pqpz?
In FDA FAERS, the most frequently co-reported reaction terms for Pegvaliase-Pqpz are arthralgia, injection site reaction, injection site erythema, injection site swelling, rash, urticaria. 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 Pegvaliase-Pqpz have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: ANAPHYLAXIS Anaphylaxis has been reported after administration of PALYNZIQ and may occur at any time during treatment [see Warnings and Precautions (5.1) ] . Administer the initial dose of PALYNZIQ under the supervision of a healthcare provider equipped to manage anaphylaxis, and closely observe patients for at least 60 minutes following injection.
Do FAERS signals prove that Pegvaliase-Pqpz 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 6dba844a-db02-44f8-8593-ce497ed9406c, effective 20260302; matched on
openfda.generic_name.exact:"PEGVALIASE-PQPZ") - 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, fieldpatient.drug.openfda.generic_name.exact, 482 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.