Talazoparib side effects: what 1,763 FDA adverse event reports show
Drug class
Poly (adp-ribose) polymerase (parp) inhibitor
Brand names
Talzenna
Who reports
1,763 reports · 80% serious · 328 with death outcome · 49% female
Used for
TALZENNA is a poly (ADP-ribose) polymerase (PARP) inhibitor indicated for: Breast Cancer • As a single agent, for the treatment of adult patients with deleterious or suspected deleterious germline BRCA -mutated (g BRCA m) HER2-negative locally advanced or metastatic breast cancer. Select patients for therapy based on an FDA-approved companion diagnostic for TALZENNA.
What it is
Talazoparib is an inhibitor of mammalian polyadenosine 5'-diphosphoribose (ADP-ribose) polymerase (PARP) enzymes. TALZENNA contains talazoparib tosylate.
Boxed warning
None in the current label
Causality screen of the 23 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.
- 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. 12 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 |
|---|---|---|---|---|---|---|
| Haematotoxicity | 47 | 60.6 45.7–80.4ROR 62.2 · χ² 2,683 / p <1e-300 | 58.9 EB05 46.1 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious PRR 43.5 · ♀ 84% (drug 49%) · 98% clinician | no trial data cached |
| Neoplasm progression | 171 | 58.2 50.5–67.2ROR 64.4 · χ² 9,528 / p <1e-300 | 57.6 EB05 50.7 · IC025 +5.4 3/3 methods agree | Not in label — unassessed | serious PRR 36.3 · ♀ 72% (drug 49%) | no trial data cached |
| Prostatic specific antigen increased | 39 | 33.6 24.6–45.8ROR 34.3 · χ² 1,198 / p 1e-262 | 33.0 EB05 25.2 · IC025 +4.0 3/3 methods agree | Lab value / disease marker | serious PRR 30.3 · ♀ 0% (drug 49%) | no trial data cached |
| Metastases to bone | 27 | 19.7 13.5–28.6ROR 20.0 · χ² 459 / p 3e-102 | 19.4 EB05 13.9 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 14.2 · ♀ 81% (drug 49%) · 100% clinician | no trial data cached |
| Anaemia (low red blood cells) | 273 | 17.0 15.3–19.0ROR 20.0 · χ² 4,137 / p <1e-300 | 17.0 EB05 15.4 · IC025 +3.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 12.4 | no trial data cached |
| Metastases to liver | 22 | 14.9 9.9–22.6ROR 15.1 · χ² 272 / p 2e-61 | 14.4 EB05 9.7 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 10.8 · ♀ 95% (drug 49%) · 100% clinician | no trial data cached |
| Pancytopenia (all blood cells low) | 67 | 14.3 11.3–18.1ROR 14.8 · χ² 818 / p 4e-180 | 14.2 EB05 11.5 · IC025 +3.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 10.3 · 93% clinician | no trial data cached |
| Febrile neutropenia | 68 | 12.2 9.7–15.4ROR 12.7 · χ² 691 / p 1e-152 | 12.0 EB05 9.7 · IC025 +3.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.8 · 96% clinician | no trial data cached |
| Cytopenia | 12 | 12.0 6.8–21.0ROR 12.0 · χ² 110 / p 6e-26 | 10.3 EB05 5.6 · IC025 +2.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.8 | no trial data cached |
| Metastases to lung | 11 | 11.3 6.3–20.5ROR 11.4 · χ² 94 / p 2e-22 | 9.5 EB05 5.1 · IC025 +1.9 3/3 methods agree | Not in label — unassessed | serious PRR 8.2 | no trial data cached |
| Full blood count decreased | 19 | 11.2 7.2–17.5ROR 11.3 · χ² 167 / p 2e-38 | 10.2 EB05 6.5 · IC025 +2.4 3/3 methods agree | Lab value / disease marker | serious PRR 8.6 | no trial data cached |
| Myelodysplastic syndrome | 13 | 10.7 6.2–18.4ROR 10.8 · χ² 105 / p 7e-25 | 9.1 EB05 5.2 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.7 | no trial data cached |
| Thrombocytopenia (low platelets) | 95 | 10.1 8.3–12.3ROR 10.7 · χ² 777 / p 3e-171 | 9.9 EB05 8.3 · IC025 +2.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.5 · 94% clinician | no trial data cached |
| Haemoglobin decreased | 80 | 9.3 7.5–11.5ROR 9.6 · χ² 583 / p 4e-129 | 9.0 EB05 7.4 · IC025 +2.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.4 | no trial data cached |
| Acute myeloid leukaemia | 12 | 9.2 5.2–16.1ROR 9.2 · χ² 79 / p 3e-19 | 7.5 EB05 4.3 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.6 | no trial data cached |
| Red blood cell count decreased | 21 | 8.7 5.7–13.4ROR 8.8 · χ² 136 / p 9e-32 | 7.7 EB05 5.2 · IC025 +2.2 3/3 methods agree | Lab value / disease marker | serious PRR 6.3 | no trial data cached |
| Malignant neoplasm progression | 70 | 8.2 6.5–10.3ROR 8.5 · χ² 436 / p 5e-97 | 7.9 EB05 6.4 · IC025 +2.6 3/3 methods agree | Reporting / coding artifact | serious PRR 6.0 | no trial data cached |
| Platelet count decreased | 73 | 8.2 6.5–10.2ROR 8.5 · χ² 453 / p 7e-101 | 7.9 EB05 6.4 · IC025 +2.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.3 | no trial data cached |
| Neutrophil count decreased | 25 | 7.3 5.0–10.8ROR 7.4 · χ² 131 / p 1e-30 | 6.6 EB05 4.7 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.1 · 96% clinician | no trial data cached |
| Myelosuppression | 16 | 5.6 3.4–9.1ROR 5.6 · χ² 56 / p 4e-14 | 4.9 EB05 3.2 · IC025 +1.5 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 4.0 | no trial data cached |
| Pneumonitis | 12 | 5.3 3.0–9.3ROR 5.3 · χ² 37 / p 5e-10 | 4.5 EB05 2.7 · IC025 +1.2 3/3 methods agree | Not in label — unassessed | serious PRR 3.9 | no trial data cached |
| Leukopenia (low white blood cells) | 21 | 5.0 3.3–7.7ROR 5.1 · χ² 64 / p 8e-16 | 4.5 EB05 3.1 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 · 90% clinician | no trial data cached |
| Neutropenia (low neutrophils (infection-fighting cells)) | 56 | 4.9 3.8–6.4ROR 5.0 · χ² 172 / p 1e-39 | 4.7 EB05 3.8 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.7 | 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 |
|---|---|---|---|---|---|---|
| Anaemia (low red blood cells) | 273 | 17.0 15.3–19.0ROR 20.0 · χ² 4,137 / p <1e-300 | 17.0 EB05 15.4 · IC025 +3.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 12.4 | no trial data cached |
| Neoplasm progression | 171 | 58.2 50.5–67.2ROR 64.4 · χ² 9,528 / p <1e-300 | 57.6 EB05 50.7 · IC025 +5.4 3/3 methods agree | Not in label — unassessed | serious PRR 36.3 · ♀ 72% (drug 49%) | no trial data cached |
| Thrombocytopenia (low platelets) | 95 | 10.1 8.3–12.3ROR 10.7 · χ² 777 / p 3e-171 | 9.9 EB05 8.3 · IC025 +2.9 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 7.5 · 94% clinician | no trial data cached |
| Haemoglobin decreased | 80 | 9.3 7.5–11.5ROR 9.6 · χ² 583 / p 4e-129 | 9.0 EB05 7.4 · IC025 +2.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.4 | no trial data cached |
| Platelet count decreased | 73 | 8.2 6.5–10.2ROR 8.5 · χ² 453 / p 7e-101 | 7.9 EB05 6.4 · IC025 +2.6 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 6.3 | no trial data cached |
| Malignant neoplasm progression | 70 | 8.2 6.5–10.3ROR 8.5 · χ² 436 / p 5e-97 | 7.9 EB05 6.4 · IC025 +2.6 3/3 methods agree | Reporting / coding artifact | serious PRR 6.0 | no trial data cached |
| Febrile neutropenia | 68 | 12.2 9.7–15.4ROR 12.7 · χ² 691 / p 1e-152 | 12.0 EB05 9.7 · IC025 +3.1 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 8.8 · 96% clinician | no trial data cached |
| Pancytopenia (all blood cells low) | 67 | 14.3 11.3–18.1ROR 14.8 · χ² 818 / p 4e-180 | 14.2 EB05 11.5 · IC025 +3.3 3/3 methods agree | Labeled (related wording) related wording | serious PRR 10.3 · 93% clinician | no trial data cached |
| Neutropenia (low neutrophils (infection-fighting cells)) | 56 | 4.9 3.8–6.4ROR 5.0 · χ² 172 / p 1e-39 | 4.7 EB05 3.8 · IC025 +1.8 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 3.7 | no trial data cached |
| Haematotoxicity | 47 | 60.6 45.7–80.4ROR 62.2 · χ² 2,683 / p <1e-300 | 58.9 EB05 46.1 · IC025 +4.7 3/3 methods agree | Not in label — unassessed | serious PRR 43.5 · ♀ 84% (drug 49%) · 98% clinician | no trial data cached |
| Prostatic specific antigen increased | 39 | 33.6 24.6–45.8ROR 34.3 · χ² 1,198 / p 1e-262 | 33.0 EB05 25.2 · IC025 +4.0 3/3 methods agree | Lab value / disease marker | serious PRR 30.3 · ♀ 0% (drug 49%) | no trial data cached |
| Metastases to bone | 27 | 19.7 13.5–28.6ROR 20.0 · χ² 459 / p 3e-102 | 19.4 EB05 13.9 · IC025 +3.2 3/3 methods agree | Not in label — unassessed | serious PRR 14.2 · ♀ 81% (drug 49%) · 100% clinician | no trial data cached |
| Neutrophil count decreased | 25 | 7.3 5.0–10.8ROR 7.4 · χ² 131 / p 1e-30 | 6.6 EB05 4.7 · IC025 +2.0 3/3 methods agree | Labeled adverse reaction exact term | serious PRR 5.1 · 96% clinician | no trial data cached |
| Metastases to liver | 22 | 14.9 9.9–22.6ROR 15.1 · χ² 272 / p 2e-61 | 14.4 EB05 9.7 · IC025 +2.8 3/3 methods agree | Not in label — unassessed | serious PRR 10.8 · ♀ 95% (drug 49%) · 100% clinician | no trial data cached |
| Leukopenia (low white blood cells) | 21 | 5.0 3.3–7.7ROR 5.1 · χ² 64 / p 8e-16 | 4.5 EB05 3.1 · IC025 +1.5 3/3 methods agree | Not in label — unassessed | serious PRR 3.7 · 90% clinician | 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.
- Haematotoxicity — n=47, PRR 60.6
- Neoplasm progression — n=171, PRR 58.2
- Metastases to bone — n=27, PRR 19.7
- Metastases to liver — n=22, PRR 14.9
- Leukopenia — n=21, PRR 5.0
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 Talazoparib?
In FDA FAERS, the most frequently co-reported reaction terms for Talazoparib are anaemia, neoplasm progression, thrombocytopenia, haemoglobin decreased, platelet count decreased, febrile neutropenia. 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 Talazoparib have an FDA boxed warning?
No. The FDA label retrieved for Talazoparib has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Talazoparib 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 b653221e-971f-4452-92d4-797924f1ff59, effective 20240709; matched on
openfda.generic_name.exact:"TALAZOPARIB") - 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, 35 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.