Venetoclax side effects: what 61,217 FDA adverse event reports show
Drug class
BCL-2 Inhibitor
Brand names
Venclexta
Who reports
61,217 reports · 90% serious · 17,332 with death outcome · 38% female
Used for
VENCLEXTA is a BCL-2 inhibitor indicated: For the treatment of adult patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). ( 1.1 ) In combination with azacitidine, or decitabine, or low-dose cytarabine for the treatment of newly diagnosed acute myeloid leukemia (AML) in adults 75 years or older, or who have comorbidities that preclude use of intensive induction chemotherapy.
What it is
Venetoclax is a BCL-2 inhibitor. It is a light yellow to dark yellow solid with the empirical formula C 45 H 50 ClN 7 O 7 S and a molecular weight of 868.44. Venetoclax is described chemically.
Boxed warning
None in the current label
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). 1,128 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 |
|---|---|---|---|---|---|---|
| Allogenic stem cell transplantation | 83 | 394.0 287.0–540.8ROR 394.5 · calibrated p 2e-12 ✓ | 174.9 EB05 145.5 · IC025 +6.1 3/3 methods agree | Not in label — unassessed | serious n=82 | not reported in cached trials |
| Acute myeloid leukaemia refractory | 72 | 258.1 189.9–350.8ROR 258.4 · calibrated p 1e-10 ✓ | 141.2 EB05 115.9 · IC025 +5.8 3/3 methods agree | Labeled (related wording) related wording | serious n=72 | not reported in cached trials |
| Autologous haematopoietic stem cell transplant | 33 | 205.9 133.6–317.5ROR 206.1 · calibrated p 2e-9 ✓ | 119.5 EB05 89.0 · IC025 +4.9 3/3 methods agree | Not in label — unassessed | serious n=33 | not reported in cached trials |
| Platelet transfusion | 386 | 148.7 131.9–167.5ROR 149.6 · calibrated p 5e-9 ✓ | 103.0 EB05 94.6 · IC025 +6.3 3/3 methods agree | Not in label — unassessed | serious n=386 · 77% consumer | not reported in cached trials |
| T-cell prolymphocytic leukaemia | 28 | 147.4 94.6–229.9ROR 147.5 · calibrated p 2e-8 ✓ | 96.3 EB05 69.9 · IC025 +4.6 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=28 · 100% clinician | not reported in cached trials |
| Chronic lymphocytic leukaemia recurrent | 204 | 143.2 121.6–168.7ROR 143.7 · calibrated p 8e-9 ✓ | 99.9 EB05 88.9 · IC025 +6.1 3/3 methods agree | Labeled (related wording) related wording | serious n=204 | not reported in cached trials |
| Acute myeloid leukaemia recurrent | 602 | 135.2 123.0–148.5ROR 136.5 · calibrated p 1e-8 ✓ | 96.5 EB05 90.2 · IC025 +6.4 3/3 methods agree | Labeled (related wording) related wording | serious n=601 | NCT04161885: 3/214 (1.4%) on Venetoclax (serious AE) |
| Aspiration bone marrow | 36 | 125.1 85.3–183.3ROR 125.1 · calibrated p 6e-8 ✓ | 87.4 EB05 65.9 · IC025 +4.8 3/3 methods agree | Labeled (related wording) related wording | serious n=36 · 100% clinician | not reported in cached trials |
| Blastic plasmacytoid dendritic cell neoplasia | 21 | 124.2 75.3–204.8ROR 124.2 · calibrated p 1e-7 ✓ | 84.3 EB05 58.1 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=21 | not reported in cached trials |
| Protothecosis | 25 | 123.9 78.3–195.9ROR 123.9 · calibrated p 1e-7 ✓ | 85.1 EB05 60.6 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=25 · ♀ 100% (drug 38%) · 100% clinician | not reported in cached trials |
| Minimal residual disease | 108 | 102.5 82.7–127.1ROR 102.7 · calibrated p 1e-7 ✓ | 77.8 EB05 66.2 · IC025 +5.5 3/3 methods agree | Not in label — unassessed | serious n=107 · 92% clinician | not reported in cached trials |
| Chronic lymphocytic leukaemia refractory | 21 | 98.3 60.5–159.8ROR 98.3 · calibrated p 6e-7 ✓ | 71.6 EB05 49.4 · IC025 +4.1 3/3 methods agree | Labeled (related wording) related wording | serious n=20 · 100% clinician | not reported in cached trials |
| Cord blood transplant therapy | 18 | 90.5 53.8–152.3ROR 90.6 · calibrated p 1e-6 ✓ | 66.7 EB05 44.7 · IC025 +3.8 3/3 methods agree | Reporting / coding artifact | serious n=18 | not reported in cached trials |
| Red blood cell transfusion | 82 | 88.3 69.2–112.6ROR 88.4 · calibrated p 4e-7 ✓ | 69.1 EB05 57.4 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious n=82 | not reported in cached trials |
| Chronic lymphocytic leukaemia | 770 | 65.9 61.1–71.2ROR 66.8 · calibrated p 2e-6 ✓ | 55.2 EB05 52.0 · IC025 +5.6 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious n=767 | not reported in cached trials |
| Chronic lymphocytic leukaemia transformation | 32 | 60.9 41.8–88.8ROR 61.0 · calibrated p 8e-6 ✓ | 50.3 EB05 37.3 · IC025 +4.3 3/3 methods agree | Labeled (related wording) related wording | serious n=32 · 100% clinician | not reported in cached trials |
| Bone marrow transplant | 272 | 57.6 50.7–65.5ROR 57.9 · calibrated p 6e-6 ✓ | 49.2 EB05 44.5 · IC025 +5.3 3/3 methods agree | Not in label — unassessed | serious n=272 · 79% consumer | not reported in cached trials |
| Tumour lysis syndrome | 1,145 | 51.6 48.5–54.9ROR 52.6 · calibrated p 1e-5 ✓ | 44.9 EB05 42.7 · IC025 +5.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 28.4 | not reported in cached trials |
| Mantle cell lymphoma recurrent | 56 | 51.4 38.8–68.1ROR 51.5 · calibrated p 2e-5 ✓ | 44.1 EB05 35.2 · IC025 +4.6 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=56 · ♀ 18% (drug 38%) | not reported in cached trials |
| Blast cell count increased | 137 | 51.3 42.9–61.4ROR 51.4 · calibrated p 1e-5 ✓ | 44.4 EB05 38.5 · IC025 +5.0 3/3 methods agree | Lab value / disease marker | serious n=135 | not reported in cached trials |
| Mantle cell lymphoma | 191 | 49.3 42.4–57.4ROR 49.4 · calibrated p 2e-5 ✓ | 43.0 EB05 38.1 · IC025 +5.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=189 | not reported in cached trials |
| Acute myeloid leukaemia | 1,890 | 47.3 45.1–49.6ROR 48.7 · calibrated p 2e-5 ✓ | 41.6 EB05 40.0 · IC025 +5.3 3/3 methods agree | Likely indication confounding term in indications; also in warnings | serious PRR 26.5 | NCT04161885: 1/216 (0.5%) on Venetoclax (serious AE) |
| Refractory cancer | 26 | 46.6 30.9–70.2ROR 46.6 · calibrated p 4e-5 ✓ | 40.0 EB05 28.7 · IC025 +3.9 3/3 methods agree | Not in label — unassessed | serious n=26 · ♀ 100% (drug 38%) | not reported in cached trials |
| Congenital aplasia | 33 | 44.0 30.6–63.2ROR 44.0 · calibrated p 5e-5 ✓ | 38.2 EB05 28.5 · IC025 +4.1 3/3 methods agree | Not in label — unassessed | serious n=33 · ♀ 0% (drug 38%) · 100% clinician | not reported in cached trials |
| B-cell small lymphocytic lymphoma | 25 | 42.3 27.9–64.2ROR 42.4 · calibrated p 7e-5 ✓ | 36.8 EB05 26.2 · IC025 +3.8 3/3 methods agree | Labeled (related wording) related wording | serious n=25 · 100% clinician | not reported in cached trials |
| Hospice care | 1,056 | 41.1 38.5–43.8ROR 41.8 · calibrated p 4e-5 ✓ | 36.7 EB05 34.9 · IC025 +5.1 3/3 methods agree | Not in label — unassessed | serious PRR 33.8 | not reported in cached trials |
| Stem cell transplant | 242 | 37.1 32.5–42.3ROR 37.2 · calibrated p 8e-5 ✓ | 33.4 EB05 30.0 · IC025 +4.8 3/3 methods agree | Not in label — unassessed | serious n=242 | not reported in cached trials |
| Infusion | 40 | 36.7 26.5–50.9ROR 36.8 · calibrated p 1e-4 ✓ | 32.8 EB05 25.1 · IC025 +4.0 3/3 methods agree | Not in label — unassessed | serious n=40 · 100% consumer | not reported in cached trials |
| Cytopenia | 1,135 | 35.9 33.8–38.1ROR 36.5 · calibrated p 9e-5 ✓ | 32.5 EB05 31.0 · IC025 +4.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 20.7 | NCT04161885: 1/214 (0.5%) on Venetoclax (serious AE) |
| Blast cells present | 44 | 34.6 25.3–47.1ROR 34.6 · calibrated p 2e-4 ✓ | 31.1 EB05 24.1 · IC025 +4.0 3/3 methods agree | Lab value / disease marker | serious n=44 · ♀ 59% (drug 38%) | not reported in cached trials |
| Transfusion | 857 | 30.3 28.3–32.5ROR 30.8 · calibrated p 2e-4 ✓ | 27.9 EB05 26.4 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious PRR 18.6 · 89% consumer | not reported in cached trials |
| Myelosuppression | 2,662 | 29.0 27.9–30.2ROR 30.3 · calibrated p 2e-4 ✓ | 26.8 EB05 26.0 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious PRR 17.1 · 97% clinician | NCT04161885: 1/214 (0.5%) on Venetoclax (serious AE) |
| Transformation to acute myeloid leukaemia | 51 | 28.7 21.6–38.2ROR 28.8 · calibrated p 4e-4 ✓ | 26.3 EB05 20.8 · IC025 +3.9 3/3 methods agree | Labeled (related wording) related wording | serious n=50 | not reported in cached trials |
| Transplant | 180 | 28.0 24.1–32.6ROR 28.1 · calibrated p 4e-4 ✓ | 25.9 EB05 22.9 · IC025 +4.4 3/3 methods agree | Not in label — unassessed | serious n=179 | NCT04161885: 1/30 (3.3%) on Venetoclax (serious AE) |
| Investigation abnormal | 99 | 26.1 21.3–32.1ROR 26.2 · calibrated p 6e-4 ✓ | 24.2 EB05 20.5 · IC025 +4.1 3/3 methods agree | Labeled (related wording) related wording | serious n=86 · 83% consumer | not reported in cached trials |
| Respiratory moniliasis | 18 | 24.8 15.3–40.0ROR 24.8 · calibrated p 0.001 ✓ | 22.6 EB05 15.0 · IC025 +3.1 3/3 methods agree | Not in label — unassessed | serious n=18 | not reported in cached trials |
| Aspergillus infection | 428 | 24.2 21.9–26.6ROR 24.3 · calibrated p 8e-4 ✓ | 22.6 EB05 20.8 · IC025 +4.3 3/3 methods agree | Not in label — unassessed | serious n=426 | not reported in cached trials |
| Leukaemia recurrent | 108 | 23.3 19.2–28.3ROR 23.4 · calibrated p 0.001 ✓ | 21.8 EB05 18.6 · IC025 +4.0 3/3 methods agree | Likely indication confounding shares a disease stem with the indications wording | serious n=108 | NCT04161885: 3/214 (1.4%) on Venetoclax (serious AE) |
| Granulocyte count decreased | 113 | 23.1 19.1–28.0ROR 23.2 · calibrated p 0.001 ✓ | 21.6 EB05 18.5 · IC025 +4.0 3/3 methods agree | Lab value / disease marker | serious n=113 · 100% clinician | not reported in cached trials |
| Blood uric acid abnormal | 25 | 22.5 15.0–33.8ROR 22.5 · calibrated p 0.002 ✓ | 20.9 EB05 14.8 · IC025 +3.3 3/3 methods agree | Lab value / disease marker | serious n=24 | 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 Venetoclax 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 (6 of 40 signal terms matched).
- NCT04161885 — A Study Evaluating Safety and Efficacy of Venetoclax in Combination With Azacitidine Versus Standard of Care A (N=465, PHASE3; 266 AE terms posted; arms: Part 1: Venetoclax 200 mg QD 28 Days + A; Part 1: Venetoclax 200 mg QD 14 Days + A; Part 2: Best Supportive Care; Part 2: Venetoclax 200 mg QD 28 Days + A)
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 |
|---|---|---|---|---|---|---|
| Death | 10,178 | 4.1 4.0–4.2ROR 4.7 · calibrated p 0.270 | 4.0 EB05 4.0 · IC025 +2.0 3/3 methods agree | Outcome field, not a reaction | serious PRR 2.6 | not reported in cached trials |
| Off label use (used outside approved label) | 6,840 | 2.7 2.7–2.8ROR 2.9 · calibrated p 0.650 | 2.7 EB05 2.6 · IC025 +1.4 3/3 methods agree | Reporting / coding artifact | serious PRR 2.7 | not reported in cached trials |
| Neutropenia (low neutrophils (infection-fighting cells)) | 3,427 | 8.9 8.6–9.2ROR 9.3 · calibrated p 0.041 ✓ | 8.7 EB05 8.4 · IC025 +3.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.5 | NCT04161885: 7/214 (3.3%) on Venetoclax (serious AE) |
| Febrile neutropenia | 3,114 | 16.9 16.3–17.5ROR 17.7 · calibrated p 0.003 ✓ | 16.1 EB05 15.6 · IC025 +3.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 10.3 | NCT04161885: 7/214 (3.3%) on Venetoclax (serious AE) |
| Platelet count decreased | 2,824 | 9.3 9.0–9.7ROR 9.7 · calibrated p 0.036 ✓ | 9.1 EB05 8.8 · IC025 +3.1 3/3 methods agree | Labeled (related wording) related wording | serious PRR 6.7 | NCT04161885: 2/214 (0.9%) on Venetoclax (serious AE) |
| Pyrexia (fever) | 2,765 | 2.7 2.7–2.9ROR 2.8 · calibrated p 0.683 | 2.7 EB05 2.7 · IC025 +1.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.1 | NCT04161885: 5/214 (2.3%) on Venetoclax (serious AE) |
| Pneumonia (lung infection) | 2,672 | 2.8 2.7–3.0ROR 2.9 · calibrated p 0.649 | 2.8 EB05 2.7 · IC025 +1.4 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 1.8 | NCT04161885: 1/216 (0.5%) on Venetoclax (serious AE) |
| Myelosuppression | 2,662 | 29.0 27.9–30.2ROR 30.3 · calibrated p 2e-4 ✓ | 26.8 EB05 26.0 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious PRR 17.1 · 97% clinician | NCT04161885: 1/214 (0.5%) on Venetoclax (serious AE) |
| Fatigue (tiredness) | 2,637 | 1.2 1.1–1.2ROR 1.2 · calibrated p 0.420 | 1.2 EB05 1.1 · IC025 +0.2 | Labeled adverse reaction exact term | serious PRR 1.1 · 72% consumer | NCT04161885: 1/214 (0.5%) on Venetoclax (serious AE) |
| Diarrhoea (diarrhea) | 2,374 | 1.3 1.2–1.3ROR 1.3 · calibrated p 0.492 | 1.3 EB05 1.2 · IC025 +0.3 | Labeled adverse reaction exact term | serious PRR 1.1 | NCT04161885: 3/214 (1.4%) on Venetoclax (serious AE) |
| White blood cell count decreased | 2,290 | 7.4 7.1–7.7ROR 7.6 · calibrated p 0.077 | 7.2 EB05 7.0 · IC025 +2.8 3/3 methods agree | Labeled (related wording) related wording | serious PRR 5.8 | NCT04161885: 55/214 (25.7%) on Venetoclax |
| Nausea | 2,130 | 0.9 0.9–1.0ROR 0.9 · calibrated p 0.257 | 0.9 EB05 0.9 · IC025 -0.2 PRR-only: not supported by EBGM or IC | Labeled adverse reaction exact term | serious PRR 0.9 | NCT04161885: 1/214 (0.5%) on Venetoclax (serious AE) |
| Thrombocytopenia (low platelets) | 2,098 | 6.6 6.3–6.8ROR 6.7 · calibrated p 0.109 | 6.4 EB05 6.2 · IC025 +2.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.1 | NCT04161885: 1/214 (0.5%) on Venetoclax (serious AE) |
| Infection | 1,984 | 4.8 4.6–5.0ROR 4.9 · calibrated p 0.247 | 4.7 EB05 4.5 · IC025 +2.2 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.7 | NCT04161885: 1/214 (0.5%) on Venetoclax (serious AE) |
| Anaemia (low red blood cells) | 1,926 | 3.5 3.3–3.6ROR 3.6 · calibrated p 0.470 | 3.5 EB05 3.3 · IC025 +1.7 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 2.4 | NCT04161885: 1/214 (0.5%) on Venetoclax (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.
- Allogenic stem cell transplantation — n=83, PRR 394.0
- Autologous haematopoietic stem cell transplant — n=33, PRR 205.9
- Platelet transfusion — n=386, PRR 148.7
- Blastic plasmacytoid dendritic cell neoplasia — n=21, PRR 124.2
- Protothecosis — n=25, PRR 123.9
- Minimal residual disease — n=108, PRR 102.5
- Red blood cell transfusion — n=82, PRR 88.3
- Bone marrow transplant — n=272, PRR 57.6
- Refractory cancer — n=26, PRR 46.6
- Congenital aplasia — n=33, PRR 44.0
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 Venetoclax?
In FDA FAERS, the most frequently co-reported reaction terms for Venetoclax are neutropenia, febrile neutropenia, platelet count decreased, pyrexia, pneumonia, myelosuppression. 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 Venetoclax have an FDA boxed warning?
No. The FDA label retrieved for Venetoclax has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Venetoclax 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 b118a40d-6b56-cee3-10f6-ded821a97018, effective 20260520; matched on
openfda.generic_name.exact:"VENETOCLAX") - 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, 1,168 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
VENETOCLAX, 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.