Omalizumab side effects: what 84,416 FDA adverse event reports show
Drug class
Anti-IgE
Brand names
Xolair, Xolair Pfs
Who reports
84,416 reports · 53% serious · 2,453 with death outcome · 74% female
Used for
XOLAIR is an anti-IgE antibody indicated for: Moderate to severe persistent asthma in adults and pediatric patients 6 years of age and older with a positive skin test or in vitro reactivity to a perennial aeroallergen and symptoms that are inadequately.
What it is
Omalizumab is a recombinant DNA-derived humanized IgG1κ monoclonal antibody that selectively binds to human immunoglobulin E (IgE). The antibody has a molecular weight of approximately 149 kiloDaltons. XOLAIR is produced by a Chinese hamster ovary cell suspension culture.
Boxed warning
ANAPHYLAXIS Anaphylaxis presenting as bronchospasm, hypotension, syncope, urticaria, and/or angioedema of the throat or tongue, has been reported to occur after administration of XOLAIR. Anaphylaxis has occurred as early as after the first dose of XOLAIR, but also has occurred beyond 1 year after beginning regularly administered treatment.
Causality screen of the 40 strongest signals
What the badges mean
- 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). 1,212 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 |
|---|---|---|---|---|---|---|
| Urticaria thermal | 96 | 507.6 357.2–721.3ROR 508.2 · calibrated p 2e-13 ✓ | 159.9 EB05 134.8 · IC025 +6.1 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=90 · ♀ 100% (drug 74%) | not reported in cached trials |
| Forced expiratory flow decreased | 62 | 443.5 291.9–673.8ROR 443.8 · calibrated p 2e-12 ✓ | 150.5 EB05 121.6 · IC025 +5.7 3/3 methods agree | Lab value / disease marker | serious n=62 · ♀ 49% (drug 74%) | not reported in cached trials |
| Chronic spontaneous urticaria | 689 | 420.0 371.3–475.0ROR 423.4 · calibrated p 4e-13 ✓ | 154.0 EB05 144.6 · IC025 +7.0 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=579 | NCT03580356: 4/321 (1.2%) on Omalizumab; 1/103 (1.0%) control |
| Fev1/fvc ratio decreased | 70 | 347.5 241.2–500.5ROR 347.7 · calibrated p 1e-11 ✓ | 138.3 EB05 113.2 · IC025 +5.8 3/3 methods agree | Lab value / disease marker | serious n=70 | not reported in cached trials |
| Idiopathic urticaria | 562 | 333.4 293.6–378.6ROR 335.6 · calibrated p 4e-12 ✓ | 140.5 EB05 131.1 · IC025 +6.8 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=53 · 89% consumer | not reported in cached trials |
| Forced expiratory volume decreased | 1,613 | 330.5 306.7–356.1ROR 336.9 · calibrated p 3e-12 ✓ | 140.5 EB05 134.8 · IC025 +7.0 3/3 methods agree | Lab value / disease marker | serious n=1,604 | not reported in cached trials |
| Smoke sensitivity | 153 | 249.8 199.3–312.9ROR 250.2 · calibrated p 9e-11 ✓ | 121.9 EB05 106.5 · IC025 +6.2 3/3 methods agree | Labeled (related wording) related wording | serious n=153 | not reported in cached trials |
| Perfume sensitivity | 258 | 213.4 180.6–252.3ROR 214.1 · calibrated p 3e-10 ✓ | 113.2 EB05 102.1 · IC025 +6.3 3/3 methods agree | Not in label — unassessed | serious n=254 | not reported in cached trials |
| Acquired factor v deficiency | 49 | 195.4 134.2–284.5ROR 195.5 · calibrated p 2e-9 ✓ | 104.5 EB05 82.1 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious n=49 · ♀ 0% (drug 74%) · 100% consumer | not reported in cached trials |
| Bronchopulmonary aspergillosis allergic | 390 | 184.2 161.5–210.1ROR 185.0 · calibrated p 9e-10 ✓ | 104.7 EB05 96.3 · IC025 +6.4 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=387 | not reported in cached trials |
| Blood immunoglobulin e decreased | 65 | 177.6 129.0–244.6ROR 177.8 · calibrated p 3e-9 ✓ | 100.1 EB05 81.3 · IC025 +5.4 3/3 methods agree | Lab value / disease marker | serious n=49 | not reported in cached trials |
| Total lung capacity increased | 98 | 138.6 108.1–177.6ROR 138.7 · calibrated p 1e-8 ✓ | 87.2 EB05 73.6 · IC025 +5.6 3/3 methods agree | Not in label — unassessed | serious n=98 · ♀ 100% (drug 74%) | not reported in cached trials |
| Vital capacity decreased | 157 | 132.6 109.2–161.0ROR 132.8 · calibrated p 2e-8 ✓ | 85.3 EB05 74.7 · IC025 +5.8 3/3 methods agree | Not in label — unassessed | serious n=157 | not reported in cached trials |
| Blood immunoglobulin e increased | 819 | 125.6 115.5–136.6ROR 126.8 · calibrated p 2e-8 ✓ | 83.0 EB05 78.3 · IC025 +6.2 3/3 methods agree | Lab value / disease marker | serious n=654 | not reported in cached trials |
| Coagulation factor v level abnormal | 40 | 117.2 80.4–170.9ROR 117.3 · calibrated p 9e-8 ✓ | 76.6 EB05 58.7 · IC025 +4.8 3/3 methods agree | Lab value / disease marker | serious n=40 · ♀ 0% (drug 74%) · 100% consumer | not reported in cached trials |
| Forced vital capacity decreased | 204 | 113.8 96.4–134.4ROR 114.1 · calibrated p 5e-8 ✓ | 77.3 EB05 68.8 · IC025 +5.8 3/3 methods agree | Not in label — unassessed | serious n=203 | not reported in cached trials |
| Humidity intolerance | 123 | 111.6 90.2–138.2ROR 111.8 · calibrated p 7e-8 ✓ | 76.0 EB05 65.3 · IC025 +5.6 3/3 methods agree | Not in label — unassessed | serious n=122 | not reported in cached trials |
| Coagulation factor deficiency | 49 | 107.4 76.7–150.3ROR 107.4 · calibrated p 1e-7 ✓ | 72.8 EB05 57.2 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=49 · ♀ 0% (drug 74%) | not reported in cached trials |
| Reversible airways obstruction | 141 | 93.4 77.0–113.5ROR 93.6 · calibrated p 2e-7 ✓ | 67.2 EB05 58.4 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious n=141 · ♀ 100% (drug 74%) | not reported in cached trials |
| Cold urticaria | 59 | 90.3 66.9–121.7ROR 90.3 · calibrated p 4e-7 ✓ | 64.8 EB05 52.1 · IC025 +5.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=55 · ♀ 100% (drug 74%) | not reported in cached trials |
| Mast cell activation syndrome | 338 | 84.8 75.0–96.0ROR 85.2 · calibrated p 4e-7 ✓ | 62.9 EB05 57.5 · IC025 +5.7 3/3 methods agree | Not in label — unassessed | serious n=269 · 74% consumer | not reported in cached trials |
| Exposure to allergen | 78 | 82.8 64.1–107.1ROR 82.9 · calibrated p 7e-7 ✓ | 61.2 EB05 50.6 · IC025 +5.1 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=77 · ♀ 100% (drug 74%) | not reported in cached trials |
| Peak expiratory flow rate decreased | 109 | 81.1 65.3–100.7ROR 81.2 · calibrated p 7e-7 ✓ | 60.4 EB05 51.5 · IC025 +5.3 3/3 methods agree | Lab value / disease marker | serious n=102 | not reported in cached trials |
| Mastocytosis | 110 | 76.9 62.1–95.3ROR 77.0 · calibrated p 1e-6 ✓ | 58.1 EB05 49.5 · IC025 +5.2 3/3 methods agree | Not in label — unassessed | serious n=92 | not reported in cached trials |
| Dust allergy | 205 | 66.7 57.2–77.9ROR 66.9 · calibrated p 2e-6 ✓ | 52.3 EB05 46.6 · IC025 +5.3 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=204 | not reported in cached trials |
| Asthmatic crisis | 766 | 65.5 60.5–71.0ROR 66.1 · calibrated p 2e-6 ✓ | 51.8 EB05 48.8 · IC025 +5.5 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=765 · 71% consumer | not reported in cached trials |
| Nasal oedema | 375 | 65.4 58.3–73.3ROR 65.7 · calibrated p 2e-6 ✓ | 51.6 EB05 47.4 · IC025 +5.4 3/3 methods agree | Labeled (related wording) related wording | serious n=364 · ♀ 97% (drug 74%) | not reported in cached trials |
| Asthma-chronic obstructive pulmonary disease overlap syndrome | 107 | 63.9 51.7–79.1ROR 64.0 · calibrated p 3e-6 ✓ | 50.4 EB05 42.9 · IC025 +5.0 3/3 methods agree | Labeled (related wording) related wording | serious n=107 | not reported in cached trials |
| Cryopyrin associated periodic syndrome | 39 | 62.0 43.6–88.1ROR 62.0 · calibrated p 6e-6 ✓ | 48.5 EB05 37.0 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=39 · ♀ 100% (drug 74%) · 100% clinician | not reported in cached trials |
| Allergy to animal | 209 | 61.5 52.8–71.5ROR 61.6 · calibrated p 4e-6 ✓ | 49.1 EB05 43.7 · IC025 +5.2 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=204 | not reported in cached trials |
| Mechanical urticaria | 90 | 59.3 47.1–74.7ROR 59.4 · calibrated p 6e-6 ✓ | 47.4 EB05 39.8 · IC025 +4.9 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=68 · ♀ 100% (drug 74%) | not reported in cached trials |
| Pulmonary function test abnormal | 302 | 59.2 52.2–67.2ROR 59.4 · calibrated p 5e-6 ✓ | 47.7 EB05 43.3 · IC025 +5.3 3/3 methods agree | Reporting / coding artifact | serious n=299 | not reported in cached trials |
| Urticaria chronic | 100 | 54.5 43.9–67.7ROR 54.6 · calibrated p 1e-5 ✓ | 44.4 EB05 37.5 · IC025 +4.9 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=69 | NCT03580356: 1/321 (0.3%) on Omalizumab; 1/103 (1.0%) control (serious AE) |
| Lung diffusion test decreased | 70 | 53.0 41.0–68.7ROR 53.1 · calibrated p 1e-5 ✓ | 43.2 EB05 35.4 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious n=69 | not reported in cached trials |
| Sputum discoloured | 1,639 | 51.8 49.2–54.7ROR 52.8 · calibrated p 1e-5 ✓ | 42.9 EB05 41.2 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious PRR 60.5 | not reported in cached trials |
| Urinary tract discomfort | 78 | 51.4 40.3–65.6ROR 51.5 · calibrated p 1e-5 ✓ | 42.2 EB05 34.9 · IC025 +4.7 3/3 methods agree | Labeled (related wording) related wording | serious n=78 · ♀ 100% (drug 74%) | not reported in cached trials |
| Alveolar osteitis | 72 | 50.2 38.9–64.7ROR 50.2 · calibrated p 2e-5 ✓ | 41.3 EB05 33.9 · IC025 +4.6 3/3 methods agree | Not in label — unassessed | serious n=72 · ♀ 100% (drug 74%) | not reported in cached trials |
| Obstructive airways disorder | 1,857 | 49.3 46.9–51.8ROR 50.4 · calibrated p 1e-5 ✓ | 41.2 EB05 39.6 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | age-adj. PRR 66.5 · serious PRR 46.3 | not reported in cached trials |
| Spirometry abnormal | 95 | 47.6 38.2–59.4ROR 47.7 · calibrated p 2e-5 ✓ | 39.7 EB05 33.4 · IC025 +4.7 3/3 methods agree | Lab value / disease marker | serious n=95 | not reported in cached trials |
| Nasal discharge discolouration | 220 | 46.8 40.5–54.0ROR 46.9 · calibrated p 2e-5 ✓ | 39.3 EB05 35.1 · IC025 +5.0 3/3 methods agree | Not in label — unassessed | serious n=212 | not reported in cached trials |
Clinical concept groups
MedDRA splits one clinical problem across several terms (e.g. "neutropenia", "neutrophil count decreased", "agranulocytosis"), which dilutes term-level signals. These rows count reports with any term in a concept group (an exact union, not a sum), compared with all other drugs. Groups are hand-built and listed in the methods.
| Concept | Reports | PRR 95% CI | Reading |
|---|---|---|---|
| Anaphylaxis / angioedema | 6,906 | 14.414.1–14.7 | signal |
| Serious infection | 6,990 | 2.32.2–2.3 | signal |
| Opportunistic infection | 865 | 1.61.5–1.7 | raised |
| Tendon disorder | 226 | 1.51.3–1.7 | raised |
| Fall / fracture | 1,852 | 1.21.2–1.3 | raised |
| Interstitial lung disease | 404 | 1.00.9–1.1 | no difference |
| Venous thromboembolism | 895 | 1.01.0–1.1 | no difference |
| Depression | 1,144 | 1.00.9–1.1 | no difference |
| Hyperglycaemia / diabetes | 1,379 | 1.00.9–1.0 | no difference |
| Rhabdomyolysis / myopathy | 264 | 0.80.7–0.9 | lower than other drugs |
| Malignancy | 1,134 | 0.70.7–0.8 | lower than other drugs |
| Myocardial infarction | 566 | 0.70.6–0.7 | lower than other drugs |
| Arrhythmia / qt | 510 | 0.70.6–0.7 | lower than other drugs |
| Heart failure | 450 | 0.60.6–0.7 | lower than other drugs |
| Stroke | 621 | 0.60.6–0.7 | lower than other drugs |
| Anaemia | 739 | 0.60.6–0.7 | lower than other drugs |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Omalizumab 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 (2 of 40 signal terms matched).
- NCT03580356 — A Phase III Study of and Efficacy of Ligelizumab in the Treatment of CSU in Adolescents and Adults Inadequatel (N=1078, PHASE3; 50 AE terms posted; arms: Ligelizumab 72mg (Adults); Ligelizumab 72mg (Adolescents); Ligelizumab 72mg (Adults+Adolescents); Ligelizumab 120 mg (Adults))
- NCT03580369 — A Phase III Study of Safety and Efficacy of Ligelizumab in the Treatment of CSU in Adolescents and Adults Inad (N=1072, PHASE3; 120 AE terms posted; arms: QGE031 72mg; QGE031 120mg; Omalizumab 300mg; Placebo Only)
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 |
|---|---|---|---|---|---|---|
| Asthma | 12,151 | 30.0 29.5–30.5ROR 34.9 · calibrated p 1e-4 ✓ | 26.8 EB05 26.4 · IC025 +4.7 3/3 methods agree | Labeled — boxed warning exact term | age-adj. PRR 37.5 · serious PRR 36.5 | not reported in cached trials |
| Urticaria (hives) | 11,363 | 18.1 17.8–18.4ROR 20.7 · calibrated p 0.002 ✓ | 16.9 EB05 16.6 · IC025 +4.0 3/3 methods agree | Labeled — boxed warning exact term | age-adj. PRR 17.2 · serious PRR 21.6 | NCT03580356: 1/321 (0.3%) on Omalizumab; 1/103 (1.0%) control (serious AE) |
| No adverse event | 10,865 | 16.1 15.8–16.4ROR 18.3 · calibrated p 0.003 ✓ | 15.2 EB05 14.9 · IC025 +3.9 3/3 methods agree | Reporting / coding artifact | age-adj. PRR 24.9 · serious PRR 2.0 | not reported in cached trials |
| Off label use (used outside approved label) | 10,711 | 3.1 3.0–3.1ROR 3.4 · calibrated p 0.515 | 3.1 EB05 3.0 · IC025 +1.6 3/3 methods agree | Reporting / coding artifact | age-adj. PRR 3.1 · serious PRR 1.6 | not reported in cached trials |
| Dyspnoea (shortness of breath) | 10,336 | 4.6 4.5–4.7ROR 5.1 · calibrated p 0.225 | 4.5 EB05 4.4 · IC025 +2.1 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 5.9 · serious PRR 6.1 | not reported in cached trials |
| Drug ineffective (drug did not work) | 8,310 | 1.6 1.5–1.6ROR 1.6 · calibrated p 0.724 | 1.6 EB05 1.5 · IC025 +0.6 | Reporting / coding artifact | age-adj. PRR 1.9 · serious PRR 2.7 | not reported in cached trials |
| Cough | 7,083 | 6.4 6.3–6.6ROR 6.9 · calibrated p 0.103 | 6.3 EB05 6.1 · IC025 +2.6 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 9.0 · serious PRR 11.0 | NCT03580356: 6/321 (1.9%) on Omalizumab; 2/103 (1.9%) control |
| Pruritus (itching) | 6,360 | 4.2 4.1–4.3ROR 4.5 · calibrated p 0.299 | 4.2 EB05 4.1 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 4.9 · serious PRR 7.8 | not reported in cached trials |
| Fatigue (tiredness) | 6,113 | 2.0 1.9–2.0ROR 2.0 · calibrated p 0.960 | 1.9 EB05 1.9 · IC025 +0.9 | Labeled adverse reaction exact term | age-adj. PRR 2.5 · serious PRR 3.1 | NCT03580356: 7/321 (2.2%) on Omalizumab; 1/103 (1.0%) control |
| Malaise (feeling unwell) | 5,689 | 3.2 3.2–3.3ROR 3.4 · calibrated p 0.512 | 3.2 EB05 3.1 · IC025 +1.6 3/3 methods agree | Not in label — unassessed | age-adj. PRR 4.5 · serious PRR 5.1 | not reported in cached trials |
| Wheezing | 5,551 | 25.6 24.9–26.2ROR 27.3 · calibrated p 4e-4 ✓ | 23.2 EB05 22.7 · IC025 +4.5 3/3 methods agree | Not in label — unassessed | age-adj. PRR 34.0 · serious PRR 32.4 | not reported in cached trials |
| Headache | 5,455 | 2.2 2.1–2.2ROR 2.2 · calibrated p 0.929 | 2.2 EB05 2.1 · IC025 +1.1 3/3 methods agree | Labeled adverse reaction exact term | age-adj. PRR 2.6 · serious PRR 3.7 | NCT03580356: 39/321 (12.1%) on Omalizumab; 7/103 (6.8%) control |
| Pneumonia (lung infection) | 5,322 | 4.1 4.0–4.2ROR 4.3 · calibrated p 0.320 | 4.1 EB05 4.0 · IC025 +2.0 3/3 methods agree | Labeled (related wording) related wording | age-adj. PRR 5.9 · serious PRR 4.5 | NCT03580369: 2/319 (0.6%) on Omalizumab (serious AE) |
| Pain | 4,429 | 1.8 1.7–1.8ROR 1.8 · calibrated p 0.848 | 1.8 EB05 1.7 · IC025 +0.8 | Labeled adverse reaction exact term | age-adj. PRR 2.6 · serious PRR 2.3 | NCT03580356: 7/321 (2.2%) on Omalizumab; 4/103 (3.9%) control |
| Anaphylactic reaction (severe allergic reaction) | 4,366 | 21.3 20.7–22.0ROR 22.4 · calibrated p 0.001 ✓ | 19.7 EB05 19.2 · IC025 +4.2 3/3 methods agree | Labeled — boxed warning synonym match | age-adj. PRR 16.8 · serious PRR 21.7 | NCT03580369: 1/316 (0.3%) on Omalizumab (serious AE) |
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.
- Perfume sensitivity — n=258, PRR 213.4
- Acquired factor v deficiency — n=49, PRR 195.4
- Total lung capacity increased — n=98, PRR 138.6
- Vital capacity decreased — n=157, PRR 132.6
- Forced vital capacity decreased — n=204, PRR 113.8
- Humidity intolerance — n=123, PRR 111.6
- Coagulation factor deficiency — n=49, PRR 107.4
- Reversible airways obstruction — n=141, PRR 93.4
- Mast cell activation syndrome — n=338, PRR 84.8
- Mastocytosis — n=110, PRR 76.9
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 Omalizumab?
In FDA FAERS, the most frequently co-reported reaction terms for Omalizumab are asthma, urticaria, dyspnoea, cough, pruritus, fatigue. 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 Omalizumab have an FDA boxed warning?
Yes. The current FDA label carries a boxed warning: ANAPHYLAXIS Anaphylaxis presenting as bronchospasm, hypotension, syncope, urticaria, and/or angioedema of the throat or tongue, has been reported to occur after administration of XOLAIR. Anaphylaxis has occurred as early as after the first dose of XOLAIR, but also has occurred beyond 1 year after beginning regularly administered treatment.
Do FAERS signals prove that Omalizumab 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 7f6a2191-adfb-48b9-9bfa-0d9920479f0d, effective 20260813; matched on
openfda.generic_name.exact:"OMALIZUMAB" AND openfda.product_type:"HUMAN PRESCRIPTION DRUG") - 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, 1,252 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
OMALIZUMAB, 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.