Peginterferon Alfa-2A side effects: what 53,742 FDA adverse event reports show
Drug class
Interferon alpha
Brand names
Pegasys
Who reports
53,742 reports · 43% serious · 1,798 with death outcome · 46% female
Used for
PEGASYS is an inducer of the innate immune response indicated for the treatment of Chronic Hepatitis C (CHC) ( 1.1 ) Adult Patients: In combination therapy with other hepatitis C virus drugs for adults with compensated liver disease. PEGASYS monotherapy is indicated only if patient has contraindication or significant intolerance to other HCV drugs.
What it is
Peginterferon alfa-2a, is a covalent conjugate of recombinant alfa-2a interferon (approximate molecular weight [MW] 20,000 daltons) with a single branched bis-monomethoxy polyethylene glycol (PEG) chain (approximate MW 40,000 daltons).
Boxed warning
RISK OF SERIOUS DISORDERS WARNING: RISK OF SERIOUS DISORDERS See full prescribing information for complete boxed warning. Risk of Serious Disorders May cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders.
Causality screen of the 40 strongest signals
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, for the 300 most-reported drugs, adjusted for age band), and flags pairs whose reports are unusually skewed by sex or come mostly from consumers. Each row also shows the PRR against the other drugs of the same FDA class, which removes most confounding by the condition being treated, and a calibrated p-value: on validation, known non-causes average an ROR of about 2, so significance is judged against that empirical null (✓ = p < 0.05 after calibration). 1,126 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 |
|---|---|---|---|---|---|---|
| Anal pruritus | 896 | 295.3 270.8–322.1ROR 300.3 · calibrated p 1e-11 ✓ | 166.8 EB05 157.8 · IC025 +7.1 3/3 methods agree | Not in label — unassessed | serious n=121 · 85% consumer | not reported in cached trials |
| Anorectal discomfort | 1,845 | 206.3 195.1–218.2ROR 213.6 · calibrated p 2e-10 ✓ | 134.4 EB05 129.3 · IC025 +6.9 3/3 methods agree | Not in label — unassessed | serious n=221 · 89% consumer | not reported in cached trials |
| Viral load decreased | 40 | 144.9 100.7–208.5ROR 145.0 · calibrated p 2e-8 ✓ | 100.5 EB05 77.0 · IC025 +5.0 3/3 methods agree | Lab value / disease marker | 100% consumer | not reported in cached trials |
| Exposure via direct contact | 222 | 118.2 101.8–137.4ROR 118.7 · calibrated p 4e-8 ✓ | 90.0 EB05 80.5 · IC025 +6.0 3/3 methods agree | Reporting / coding artifact | – | not reported in cached trials |
| Hepatitis c rna increased | 73 | 105.0 81.1–136.0ROR 105.1 · calibrated p 1e-7 ✓ | 81.0 EB05 66.5 · IC025 +5.3 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=46 | NCT00922779: 1/6,661 (0.0%) on Peginterferon Alfa-2A (serious AE) |
| Viral load | 23 | 59.3 38.2–92.0ROR 59.3 · calibrated p 1e-5 ✓ | 49.5 EB05 34.7 · IC025 +3.9 3/3 methods agree | Labeled adverse reaction exact term | – | not reported in cached trials |
| Painful defaecation | 82 | 51.4 40.8–64.7ROR 51.4 · calibrated p 1e-5 ✓ | 45.0 EB05 37.4 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious n=11 · 87% consumer | not reported in cached trials |
| Hepatitis c rna positive | 17 | 42.1 25.5–69.5ROR 42.1 · calibrated p 1e-4 ✓ | 36.6 EB05 24.2 · IC025 +3.4 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=15 | not reported in cached trials |
| Viral load increased | 378 | 41.8 37.6–46.4ROR 42.0 · calibrated p 4e-5 ✓ | 37.7 EB05 34.6 · IC025 +5.0 3/3 methods agree | Lab value / disease marker | serious n=207 | not reported in cached trials |
| Retinal exudates | 80 | 36.4 28.9–45.8ROR 36.5 · calibrated p 1e-4 ✓ | 33.1 EB05 27.4 · IC025 +4.4 3/3 methods agree | Labeled adverse reaction exact term | serious n=55 | not reported in cached trials |
| Proctalgia | 462 | 30.2 27.5–33.2ROR 30.5 · calibrated p 2e-4 ✓ | 28.0 EB05 26.0 · IC025 +4.6 3/3 methods agree | Not in label — unassessed | serious n=84 · 82% consumer | not reported in cached trials |
| Essential thrombocythaemia | 26 | 29.9 20.1–44.6ROR 29.9 · calibrated p 4e-4 ✓ | 27.3 EB05 19.6 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=13 | not reported in cached trials |
| Porphyria non-acute | 30 | 28.5 19.7–41.3ROR 28.5 · calibrated p 5e-4 ✓ | 26.2 EB05 19.2 · IC025 +3.6 3/3 methods agree | Not in label — unassessed | serious n=25 · 100% clinician | not reported in cached trials |
| Hepatitis c | 731 | 24.8 23.0–26.7ROR 25.1 · calibrated p 7e-4 ✓ | 23.3 EB05 21.9 · IC025 +4.4 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 22.9 | NCT00922779: 1/6,661 (0.0%) on Peginterferon Alfa-2A (serious AE) |
| Haemorrhoids | 1,071 | 22.6 21.2–24.0ROR 23.0 · calibrated p 0.001 ✓ | 21.4 EB05 20.3 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious PRR 7.1 · 82% consumer | NCT00081770: 1/1,035 (0.1%) on Peginterferon Alfa-2A (serious AE) |
| Remission not achieved | 32 | 21.2 14.8–30.2ROR 21.2 · calibrated p 0.002 ✓ | 19.9 EB05 14.7 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=32 · 100% clinician | not reported in cached trials |
| Red blood cell count decreased | 1,390 | 19.9 18.8–21.0ROR 20.4 · calibrated p 0.002 ✓ | 18.9 EB05 18.1 · IC025 +4.1 3/3 methods agree | Lab value / disease marker | serious PRR 15.1 · 76% consumer | NCT00081770: 1/1,019 (0.1%) on Peginterferon Alfa-2A (serious AE) |
| Chronic hepatitis c | 18 | 18.6 11.6–29.8ROR 18.6 · calibrated p 0.004 ✓ | 17.3 EB05 11.2 · IC025 +2.8 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=11 | NCT00922779: 1/6,661 (0.0%) on Peginterferon Alfa-2A (serious AE) |
| Cryoglobulinaemia | 32 | 18.5 13.0–26.4ROR 18.5 · calibrated p 0.004 ✓ | 17.5 EB05 12.9 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=29 | not reported in cached trials |
| Pregnancy of partner | 32 | 18.2 12.8–26.0ROR 18.2 · calibrated p 0.004 ✓ | 17.2 EB05 12.7 · IC025 +3.2 3/3 methods agree | Labeled (related wording) related wording | ♀ 0% (drug 46%) | not reported in cached trials |
| Viral test positive | 16 | 17.8 10.8–29.3ROR 17.8 · calibrated p 0.006 ✓ | 16.4 EB05 10.2 · IC025 +2.7 3/3 methods agree | Likely indication confounding term in indications; also in warnings | – | not reported in cached trials |
| Basedow's disease | 20 | 17.0 10.9–26.6ROR 17.0 · calibrated p 0.006 ✓ | 15.9 EB05 10.5 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious n=20 | not reported in cached trials |
| White blood cell count decreased | 4,228 | 15.8 15.3–16.3ROR 17.0 · calibrated p 0.004 ✓ | 15.2 EB05 14.8 · IC025 +3.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 16.3 | NCT00081770: 1/1,019 (0.1%) on Peginterferon Alfa-2A (serious AE) |
| Hepatic neoplasm malignant | 79 | 14.9 11.9–18.7ROR 14.9 · calibrated p 0.008 ✓ | 14.3 EB05 11.8 · IC025 +3.4 3/3 methods agree | Not in label — unassessed | serious n=79 · ♀ 19% (drug 46%) | NCT00081770: 2/1,035 (0.2%) on Peginterferon Alfa-2A (serious AE) |
| Hepatitis c virus test positive | 21 | 14.3 9.3–22.1ROR 14.3 · calibrated p 0.012 ✓ | 13.2 EB05 8.7 · IC025 +2.7 3/3 methods agree | Likely indication confounding term in indications; also in warnings | – | not reported in cached trials |
| Rash generalised | 929 | 14.3 13.4–15.2ROR 14.5 · calibrated p 0.008 ✓ | 13.8 EB05 13.1 · IC025 +3.7 3/3 methods agree | Not in label — unassessed | serious PRR 11.2 | not reported in cached trials |
| Anaemia (low red blood cells) | 6,628 | 14.0 13.7–14.3ROR 15.8 · calibrated p 0.006 ✓ | 13.5 EB05 13.3 · IC025 +3.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 11.8 | NCT00922779: 459/6,661 (6.9%) on Peginterferon Alfa-2A |
| Anorectal disorder | 69 | 13.9 10.9–17.6ROR 13.9 · calibrated p 0.011 ✓ | 13.3 EB05 10.8 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=32 | not reported in cached trials |
| Hepatic pain | 146 | 13.8 11.7–16.2ROR 13.8 · calibrated p 0.010 ✓ | 13.3 EB05 11.5 · IC025 +3.4 3/3 methods agree | Labeled (related wording) related wording | serious n=62 · 84% consumer | not reported in cached trials |
| Influenza like illness (flu-like illness) | 2,738 | 13.3 12.9–13.8ROR 14.0 · calibrated p 0.009 ✓ | 12.9 EB05 12.5 · IC025 +3.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.6 · 83% consumer | NCT00922779: 833/6,661 (12.5%) on Peginterferon Alfa-2A |
| Therapy responder | 16 | 13.0 7.9–21.5ROR 13.0 · calibrated p 0.018 ✓ | 11.6 EB05 7.0 · IC025 +2.4 3/3 methods agree | Not in label — unassessed | – | not reported in cached trials |
| Alpha 1 foetoprotein increased | 23 | 13.0 8.5–19.6ROR 13.0 · calibrated p 0.016 ✓ | 11.9 EB05 7.9 · IC025 +2.6 3/3 methods agree | Lab value / disease marker | serious n=18 | not reported in cached trials |
| Anal haemorrhage | 83 | 11.9 9.6–14.8ROR 11.9 · calibrated p 0.019 ✓ | 11.4 EB05 9.4 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=20 · 85% consumer | not reported in cached trials |
| Bleeding varicose vein | 16 | 11.8 7.2–19.5ROR 11.8 · calibrated p 0.025 ✓ | 10.3 EB05 6.2 · IC025 +2.3 3/3 methods agree | Not in label — unassessed | serious n=12 | not reported in cached trials |
| Haemorrhoidal haemorrhage | 144 | 11.7 9.9–13.9ROR 11.8 · calibrated p 0.019 ✓ | 11.3 EB05 9.8 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious n=34 · 82% consumer | NCT00081770: 1/1,019 (0.1%) on Peginterferon Alfa-2A (serious AE) |
| No therapeutic response | 347 | 11.2 10.1–12.5ROR 11.3 · calibrated p 0.021 ✓ | 10.9 EB05 10.0 · IC025 +3.3 3/3 methods agree | Reporting / coding artifact | serious PRR 7.1 | not reported in cached trials |
| Pruritus generalised | 600 | 10.9 10.1–11.9ROR 11.1 · calibrated p 0.023 ✓ | 10.6 EB05 9.9 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 5.9 · 80% consumer | not reported in cached trials |
| Retinopathy | 100 | 10.7 8.8–13.1ROR 10.7 · calibrated p 0.027 ✓ | 10.3 EB05 8.6 · IC025 +3.0 3/3 methods agree | Labeled adverse reaction exact term | serious n=82 | not reported in cached trials |
| Rash pruritic | 1,438 | 10.7 10.1–11.2ROR 10.9 · calibrated p 0.024 ✓ | 10.4 EB05 9.9 · IC025 +3.3 3/3 methods agree | Not in label — unassessed | serious PRR 5.9 · 83% consumer | not reported in cached trials |
| Angular cheilitis | 18 | 10.5 6.6–16.8ROR 10.5 · calibrated p 0.036 ✓ | 9.1 EB05 5.8 · IC025 +2.2 3/3 methods agree | Not in label — unassessed | – | not reported in cached trials |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Peginterferon Alfa-2A as a study intervention. The right-hand column of the signal table shows whether each FAERS term was also recorded in these trials, with a real denominator (10 of 40 signal terms matched).
- NCT00922779 — A Study of Ribavirin in Combination With PEGASYS (Peginterferon Alfa-2a (40KD))in Patients With Chronic Hepati (N=6661, PHASE4; 70 AE terms posted; arms: Ribavirin + Peginterferon Alfa-2a)
- NCT00081770 — Peginterferon Dose Evaluations for Previously Untreated Subjects With Chronic Hepatitis C Infected With Genoty (N=4469, PHASE3; 334 AE terms posted; arms: PegIntron 1.5 ug/kg/wk Plus REBETOL; PegIntron 1.0 ug/kg/wk Plus REBETOL; PEGASYS 180 ug/wk Plus COPEGUS)
Caveats: trial populations, doses and follow-up differ from the reporting population; AE terms are sponsor-coded and matched here by wording; absence from a trial list means the term was not reported above the sponsor's frequency threshold, not that it cannot occur.
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 |
|---|---|---|---|---|---|---|
| Fatigue (tiredness) | 9,260 | 4.7 4.6–4.8ROR 5.5 · calibrated p 0.190 | 4.6 EB05 4.6 · IC025 +2.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.4 · 80% consumer | NCT00081770: 1/1,019 (0.1%) on Peginterferon Alfa-2A (serious AE) |
| Nausea | 7,165 | 3.6 3.5–3.6ROR 4.0 · calibrated p 0.385 | 3.5 EB05 3.5 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.6 · 79% consumer | NCT00081770: 1/1,016 (0.1%) on Peginterferon Alfa-2A (serious AE) |
| Anaemia (low red blood cells) | 6,628 | 14.0 13.7–14.3ROR 15.8 · calibrated p 0.006 ✓ | 13.5 EB05 13.3 · IC025 +3.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 11.8 | NCT00922779: 459/6,661 (6.9%) on Peginterferon Alfa-2A |
| Rash | 4,878 | 4.4 4.3–4.5ROR 4.8 · calibrated p 0.261 | 4.4 EB05 4.3 · IC025 +2.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.4 | NCT00081770: 225/1,019 (22.1%) on Peginterferon Alfa-2A |
| Headache | 4,454 | 2.8 2.7–2.9ROR 2.9 · calibrated p 0.643 | 2.8 EB05 2.7 · IC025 +1.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.0 · 81% consumer | NCT00081770: 508/1,019 (49.9%) on Peginterferon Alfa-2A |
| White blood cell count decreased | 4,228 | 15.8 15.3–16.3ROR 17.0 · calibrated p 0.004 ✓ | 15.2 EB05 14.8 · IC025 +3.9 3/3 methods agree | Labeled (related wording) related wording | serious PRR 16.3 | NCT00081770: 1/1,019 (0.1%) on Peginterferon Alfa-2A (serious AE) |
| Pruritus (itching) | 4,224 | 4.4 4.3–4.5ROR 4.7 · calibrated p 0.271 | 4.4 EB05 4.2 · IC025 +2.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.0 · 78% consumer | NCT00081770: 163/1,019 (16.0%) on Peginterferon Alfa-2A |
| Pyrexia (fever) | 3,477 | 3.9 3.8–4.1ROR 4.2 · calibrated p 0.350 | 3.9 EB05 3.8 · IC025 +1.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.7 · 71% consumer | NCT00922779: 1/6,661 (0.0%) on Peginterferon Alfa-2A (serious AE) |
| Diarrhoea (diarrhea) | 3,385 | 2.1 2.0–2.1ROR 2.1 · calibrated p 0.987 | 2.1 EB05 2.0 · IC025 +1.0 | Labeled adverse reaction exact term | serious PRR 1.6 · 78% consumer | NCT00081770: 1/1,019 (0.1%) on Peginterferon Alfa-2A (serious AE) |
| Vomiting | 3,336 | 2.8 2.7–2.9ROR 2.9 · calibrated p 0.657 | 2.8 EB05 2.7 · IC025 +1.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.1 · 76% consumer | NCT00081770: 3/1,016 (0.3%) on Peginterferon Alfa-2A (serious AE) |
| Asthenia (weakness) | 3,149 | 3.3 3.2–3.4ROR 3.4 · calibrated p 0.502 | 3.3 EB05 3.2 · IC025 +1.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.9 · 73% consumer | NCT00922779: 2/6,661 (0.0%) on Peginterferon Alfa-2A (serious AE) |
| Insomnia (trouble sleeping) | 3,079 | 4.5 4.4–4.7ROR 4.8 · calibrated p 0.262 | 4.5 EB05 4.4 · IC025 +2.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.8 · 80% consumer | NCT00081770: 401/1,019 (39.4%) on Peginterferon Alfa-2A |
| Dyspnoea (shortness of breath) | 3,051 | 2.1 2.0–2.2ROR 2.2 · calibrated p 0.963 | 2.1 EB05 2.0 · IC025 +1.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 1.7 · 74% consumer | NCT00081770: 2/1,019 (0.2%) on Peginterferon Alfa-2A (serious AE) |
| Decreased appetite (loss of appetite) | 2,918 | 5.0 4.8–5.1ROR 5.2 · calibrated p 0.215 | 4.9 EB05 4.8 · IC025 +2.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.4 · 78% consumer | NCT00081770: 184/1,019 (18.1%) on Peginterferon Alfa-2A |
| Influenza like illness (flu-like illness) | 2,738 | 13.3 12.9–13.8ROR 14.0 · calibrated p 0.009 ✓ | 12.9 EB05 12.5 · IC025 +3.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.6 · 83% consumer | NCT00922779: 833/6,661 (12.5%) on Peginterferon Alfa-2A |
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.
- Anal pruritus — n=896, PRR 295.3
- Anorectal discomfort — n=1,845, PRR 206.3
- Painful defaecation — n=82, PRR 51.4
- Proctalgia — n=462, PRR 30.2
- Essential thrombocythaemia — n=26, PRR 29.9
- Porphyria non-acute — n=30, PRR 28.5
- Haemorrhoids — n=1,071, PRR 22.6 (also seen in trial arm)
- Remission not achieved — n=32, PRR 21.2
- Cryoglobulinaemia — n=32, PRR 18.5
- Basedow's disease — n=20, PRR 17.0
✓ 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 Peginterferon Alfa-2A?
In FDA FAERS, the most frequently co-reported reaction terms for Peginterferon Alfa-2A are fatigue, nausea, anaemia, rash, headache, white blood cell count decreased. 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 Peginterferon Alfa-2A have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: RISK OF SERIOUS DISORDERS WARNING: RISK OF SERIOUS DISORDERS See full prescribing information for complete boxed warning. Risk of Serious Disorders May cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders.
Do FAERS signals prove that Peginterferon Alfa-2A 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 d9290e5b-6d40-2318-e053-2995a90a9916, effective 20260902; matched on
openfda.generic_name.exact:"PEGINTERFERON ALFA-2A") - 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, 1,166 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 - ClinicalTrials.gov API v2 (query
PEGINTERFERON ALFA-2A, results-bearing studies sorted by enrollment)
Page generated 2026-10-14. 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.