Drug · FAERS side-effect profile with label screen
Palbociclib side effects: what 94,819 FDA adverse event reports show
Brand names
Ibrance
openFDA label
Who reports
94,819 reports · 53% serious · 10,577 with death outcome · 97% female
openFDA FAERS counts, all years, deduplication not applied
Used for
IBRANCE is a kinase inhibitor indicated: • for the treatment of adult patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer in combination with: o an aromatase inhibitor as initial endocrine-based therapy ( 1.1 ); or o fulvestrant in patients with disease progression following endocrine therapy.
FDA label, Indications and Usage
What it is
IBRANCE capsules for oral administration contain 125 mg, 100 mg, or 75 mg of palbociclib, a kinase inhibitor.
FDA label, Description section
Boxed warning
None in the current label
How to read this page. FAERS is a spontaneous-reporting system: counts are not incidence rates and a signal is not proof of causation.
Each reaction below is run through an automated screen — is the term in the FDA label (known), in the indications (the disease being treated), an administrative/coding term, or none of these (unlabeled)?
That screen is mechanical text matching, not a causality assessment. The 30 hand-written Bradford Hill assessments are on the causality assessment page. Not medical advice.
Causality screen of the 40 strongest signals
Labeled adverse reaction 3Labeled (related wording) 2Likely indication confounding 2Lab value / disease marker 16Not in label — unassessed 17
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.
- 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). 1,131 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.
Show:
| Reaction | Reports | PRR 95% CI · ROR · χ²/p | EBGM EB05 · IC025 | Label screen | Serious-only & strata | Trial cross-check |
|---|---|---|---|---|---|---|
| Carbohydrate antigen 27.29 increased | 57 | 134.6 96.7–187.3ROR 134.7 · calibrated p 3e-8 ✓ | 81.3 EB05 65.1 · IC025 +5.2 3/3 methods agree vs other Kinase Inhibitors: only this drug | Lab value / disease marker | serious n=41 | not reported in cached trials |
| Body surface area increased | 41 | 102.4 70.6–148.4ROR 102.4 · calibrated p 2e-7 ✓ | 67.8 EB05 52.1 · IC025 +4.7 3/3 methods agree vs other Kinase Inhibitors: PRR 412.6 (175.2–971.8) | Not in label — unassessed | serious n=39 | not reported in cached trials |
| Pik3ca-activated mutation | 102 | 100.7 79.6–127.4ROR 100.8 · calibrated p 2e-7 ✓ | 68.3 EB05 57.9 · IC025 +5.4 3/3 methods agree vs other Kinase Inhibitors: PRR 49.7 (38.2–64.5) | Not in label — unassessed | serious n=99 | not reported in cached trials |
| Neoplasm progression | 10,619 | 96.0 93.9–98.1ROR 108.0 · calibrated p 6e-8 ✓ | 66.9 EB05 65.8 · IC025 +6.0 3/3 methods agree vs other Kinase Inhibitors: PRR 109.1 (106.0–112.4) | Not in label — unassessed | age-adj. PRR 82.0 · serious PRR 46.4 | not reported in cached trials |
| Carbohydrate antigen 15-3 increased | 177 | 66.9 56.5–79.1ROR 67.0 · calibrated p 2e-6 ✓ | 51.1 EB05 45.1 · IC025 +5.2 3/3 methods agree vs other Kinase Inhibitors: PRR 120.1 (93.1–154.9) | Lab value / disease marker | serious n=166 | not reported in cached trials |
| Tumour marker abnormal | 62 | 50.1 38.0–66.0ROR 50.1 · calibrated p 2e-5 ✓ | 40.4 EB05 32.6 · IC025 +4.5 3/3 methods agree vs other Kinase Inhibitors: only this drug | Lab value / disease marker | serious n=27 | not reported in cached trials |
| Tumour marker increased | 873 | 48.9 45.5–52.7ROR 49.4 · calibrated p 1e-5 ✓ | 40.1 EB05 37.9 · IC025 +5.2 3/3 methods agree vs other Kinase Inhibitors: PRR 131.1 (116.6–147.5) | Lab value / disease marker | serious n=523 | not reported in cached trials |
| Pseudocirrhosis | 47 | 36.9 27.1–50.2ROR 36.9 · calibrated p 1e-4 ✓ | 31.3 EB05 24.5 · IC025 +4.1 3/3 methods agree vs other Kinase Inhibitors: PRR 129.0 (77.8–214.0) | Not in label — unassessed | serious n=47 · 100% clinician | not reported in cached trials |
| Metastases to eye | 30 | 34.7 23.6–51.0ROR 34.7 · calibrated p 2e-4 ✓ | 29.5 EB05 21.7 · IC025 +3.7 3/3 methods agree vs other Kinase Inhibitors: only this drug | Not in label — unassessed | serious n=30 | NCT02513394: 1/2,841 (0.0%) on Palbociclib |
| Hormone receptor positive her2 negative breast cancer | 42 | 34.0 24.6–47.1ROR 34.1 · calibrated p 2e-4 ✓ | 29.2 EB05 22.5 · IC025 +4.0 3/3 methods agree vs other Kinase Inhibitors: PRR 211.3 (111.3–401.4) | Likely indication confounding term in indications; also in warnings | serious n=42 · 100% clinician | not reported in cached trials |
| Full blood count abnormal | 1,162 | 27.3 25.7–29.0ROR 27.6 · calibrated p 4e-4 ✓ | 24.4 EB05 23.2 · IC025 +4.5 3/3 methods agree vs other Kinase Inhibitors: PRR 113.4 (102.9–124.9) | Lab value / disease marker | serious PRR 16.0 | not reported in cached trials |
| White blood cell count decreased | 11,437 | 26.0 25.5–26.5ROR 29.4 · calibrated p 3e-4 ✓ | 23.3 EB05 23.0 · IC025 +4.5 3/3 methods agree vs other Kinase Inhibitors: PRR 190.5 (183.9–197.3) | Labeled adverse reaction exact term | age-adj. PRR 23.2 · serious PRR 16.5 | NCT02513394: 1/2,841 (0.0%) on Palbociclib (serious AE) |
| Neutrophil percentage decreased | 54 | 24.9 18.8–33.0ROR 24.9 · calibrated p 9e-4 ✓ | 22.3 EB05 17.7 · IC025 +3.8 3/3 methods agree vs other Kinase Inhibitors: PRR 652.1 (260.9–1,630.1) | Lab value / disease marker | serious n=50 · 100% consumer | NCT02513394: 1/2,902 (0.0%) on Palbociclib |
| Breast cancer metastatic | 1,069 | 24.4 22.9–26.0ROR 24.7 · calibrated p 7e-4 ✓ | 22.0 EB05 20.9 · IC025 +4.3 3/3 methods agree vs other Kinase Inhibitors: PRR 57.3 (52.8–62.3) | Likely indication confounding term in indications; also in warnings | serious PRR 21.6 | NCT02513394: 2/2,841 (0.1%) on Palbociclib (serious AE) |
| Full blood count decreased | 1,993 | 24.2 23.1–25.3ROR 24.7 · calibrated p 7e-4 ✓ | 21.9 EB05 21.1 · IC025 +4.4 3/3 methods agree vs other Kinase Inhibitors: PRR 144.6 (133.5–156.7) | Lab value / disease marker | serious PRR 15.1 | not reported in cached trials |
| Lymphocyte percentage increased | 38 | 22.8 16.3–31.8ROR 22.8 · calibrated p 0.001 ✓ | 20.5 EB05 15.6 · IC025 +3.5 3/3 methods agree vs other Kinase Inhibitors: only this drug | Lab value / disease marker | serious n=33 · 100% consumer | NCT02513394: 1/2,841 (0.0%) on Palbociclib |
| Mean cell haemoglobin increased | 150 | 21.9 18.5–25.9ROR 21.9 · calibrated p 0.001 ✓ | 19.9 EB05 17.4 · IC025 +4.0 3/3 methods agree vs other Kinase Inhibitors: PRR 647.0 (374.2–1,118.6) | Lab value / disease marker | serious n=110 | NCT02513394: 1/2,902 (0.0%) on Palbociclib |
| Second primary malignancy | 686 | 19.8 18.3–21.4ROR 20.0 · calibrated p 0.002 ✓ | 18.2 EB05 17.1 · IC025 +4.0 3/3 methods agree vs other Kinase Inhibitors: PRR 47.7 (43.2–52.6) | Not in label — unassessed | serious PRR 19.9 | NCT02513394: 1/2,841 (0.0%) on Palbociclib (serious AE) |
| Metastases to chest wall | 28 | 19.4 13.2–28.5ROR 19.4 · calibrated p 0.003 ✓ | 17.6 EB05 12.7 · IC025 +3.2 3/3 methods agree vs other Kinase Inhibitors: PRR 31.9 (20.2–50.4) | Not in label — unassessed | serious n=28 | not reported in cached trials |
| Mean cell volume increased | 203 | 18.9 16.4–21.8ROR 19.0 · calibrated p 0.003 ✓ | 17.5 EB05 15.5 · IC025 +3.8 3/3 methods agree vs other Kinase Inhibitors: PRR 227.0 (168.2–306.4) | Lab value / disease marker | serious n=147 | NCT02513394: 1/2,841 (0.0%) on Palbociclib |
| Blood count abnormal | 1,152 | 17.8 16.8–18.9ROR 18.1 · calibrated p 0.003 ✓ | 16.6 EB05 15.8 · IC025 +3.9 3/3 methods agree vs other Kinase Inhibitors: PRR 40.5 (37.7–43.6) | Lab value / disease marker | serious PRR 9.4 | not reported in cached trials |
| Neoplasm recurrence | 242 | 16.9 14.8–19.3ROR 16.9 · calibrated p 0.004 ✓ | 15.7 EB05 14.1 · IC025 +3.7 3/3 methods agree vs other Kinase Inhibitors: PRR 120.8 (97.1–150.2) | Not in label — unassessed | serious n=99 | not reported in cached trials |
| White blood cell count abnormal | 441 | 16.4 14.9–18.0ROR 16.5 · calibrated p 0.005 ✓ | 15.3 EB05 14.1 · IC025 +3.8 3/3 methods agree vs other Kinase Inhibitors: PRR 27.4 (24.5–30.7) | Lab value / disease marker | serious n=168 | NCT02513394: 1/2,841 (0.0%) on Palbociclib (serious AE) |
| Metastases to bone | 1,106 | 16.0 15.0–17.0ROR 16.2 · calibrated p 0.005 ✓ | 14.9 EB05 14.2 · IC025 +3.8 3/3 methods agree vs other Kinase Inhibitors: PRR 28.1 (26.2–30.1) | Not in label — unassessed | serious PRR 16.2 | NCT02513394: 1/2,841 (0.0%) on Palbociclib |
| Cancer pain | 167 | 15.3 13.1–17.9ROR 15.4 · calibrated p 0.007 ✓ | 14.3 EB05 12.6 · IC025 +3.5 3/3 methods agree vs other Kinase Inhibitors: PRR 51.4 (41.9–63.2) | Labeled (related wording) related wording | serious n=154 | not reported in cached trials |
| Red blood cell count decreased | 1,845 | 15.2 14.5–15.9ROR 15.5 · calibrated p 0.006 ✓ | 14.2 EB05 13.7 · IC025 +3.8 3/3 methods agree vs other Kinase Inhibitors: PRR 57.3 (53.9–61.0) | Lab value / disease marker | age-adj. PRR 13.1 · serious PRR 12.0 | NCT02513394: 1/2,841 (0.0%) on Palbociclib (serious AE) |
| Metastases to skin | 66 | 15.2 11.8–19.5ROR 15.2 · calibrated p 0.007 ✓ | 14.1 EB05 11.4 · IC025 +3.3 3/3 methods agree vs other Kinase Inhibitors: PRR 17.2 (13.1–22.6) | Not in label — unassessed | serious n=65 | not reported in cached trials |
| Monocyte percentage increased | 45 | 15.0 11.1–20.2ROR 15.0 · calibrated p 0.008 ✓ | 13.9 EB05 10.7 · IC025 +3.1 3/3 methods agree vs other Kinase Inhibitors: PRR 452.9 (193.2–1,061.4) | Lab value / disease marker | serious n=41 · 100% consumer | NCT02513394: 1/2,902 (0.0%) on Palbociclib |
| Invasive lobular breast carcinoma | 30 | 13.7 9.5–19.8ROR 13.7 · calibrated p 0.013 ✓ | 12.5 EB05 8.9 · IC025 +2.8 3/3 methods agree vs other Kinase Inhibitors: PRR 129.4 (68.6–244.0) | Not in label — unassessed | serious n=26 · 100% clinician | not reported in cached trials |
| Metastases to the mediastinum | 24 | 13.5 8.9–20.4ROR 13.5 · calibrated p 0.014 ✓ | 12.2 EB05 8.2 · IC025 +2.7 3/3 methods agree vs other Kinase Inhibitors: PRR 16.7 (10.6–26.2) | Not in label — unassessed | serious n=24 | not reported in cached trials |
| Neutrophil count decreased | 2,284 | 13.2 12.6–13.7ROR 13.5 · calibrated p 0.011 ✓ | 12.5 EB05 12.0 · IC025 +3.6 3/3 methods agree vs other Kinase Inhibitors: PRR 117.9 (110.0–126.3) | Labeled adverse reaction exact term | age-adj. PRR 10.3 · serious PRR 9.8 | NCT02513394: 1/2,841 (0.0%) on Palbociclib (serious AE) |
| Metastases to pleura | 58 | 13.0 10.0–16.9ROR 13.0 · calibrated p 0.014 ✓ | 12.1 EB05 9.6 · IC025 +3.1 3/3 methods agree vs other Kinase Inhibitors: PRR 16.2 (12.1–21.7) | Not in label — unassessed | serious n=58 · 100% clinician | not reported in cached trials |
| Meningoencephalitis herpetic | 25 | 12.8 8.6–19.2ROR 12.8 · calibrated p 0.017 ✓ | 11.5 EB05 7.9 · IC025 +2.7 3/3 methods agree vs other Kinase Inhibitors: only this drug | Not in label — unassessed | serious n=25 · 100% consumer | not reported in cached trials |
| Mean cell haemoglobin concentration increased | 30 | 12.4 8.6–18.0ROR 12.4 · calibrated p 0.018 ✓ | 11.3 EB05 8.0 · IC025 +2.7 3/3 methods agree vs other Kinase Inhibitors: only this drug | Lab value / disease marker | serious n=24 | NCT02513394: 1/2,902 (0.0%) on Palbociclib |
| Monocyte count decreased | 62 | 11.9 9.2–15.3ROR 11.9 · calibrated p 0.019 ✓ | 11.1 EB05 8.8 · IC025 +3.0 3/3 methods agree vs other Kinase Inhibitors: only this drug | Lab value / disease marker | serious n=49 | NCT02513394: 13/2,841 (0.5%) on Palbociclib |
| Breast cancer recurrent | 160 | 11.8 10.0–13.8ROR 11.8 · calibrated p 0.019 ✓ | 11.1 EB05 9.7 · IC025 +3.2 3/3 methods agree vs other Kinase Inhibitors: PRR 76.7 (60.7–96.8) | Not in label — unassessed | serious n=156 | NCT02513394: 1/2,841 (0.0%) on Palbociclib (serious AE) |
| White blood cell disorder | 134 | 11.6 9.7–13.8ROR 11.6 · calibrated p 0.020 ✓ | 10.9 EB05 9.4 · IC025 +3.1 3/3 methods agree vs other Kinase Inhibitors: PRR 57.8 (45.6–73.2) | Labeled (related wording) related wording | serious n=65 | NCT02513394: 1/2,841 (0.0%) on Palbociclib (serious AE) |
| Neutropenia (low neutrophils (infection-fighting cells)) | 6,728 | 11.5 11.2–11.8ROR 12.3 · calibrated p 0.015 ✓ | 11.0 EB05 10.8 · IC025 +3.4 3/3 methods agree vs other Kinase Inhibitors: PRR 96.9 (93.4–100.5) | Labeled adverse reaction exact term | age-adj. PRR 8.6 · serious PRR 11.8 | NCT02513394: 13/2,841 (0.5%) on Palbociclib (serious AE) |
| Decreased immune responsiveness | 484 | 11.5 10.5–12.6ROR 11.5 · calibrated p 0.020 ✓ | 10.9 EB05 10.1 · IC025 +3.3 3/3 methods agree vs other Kinase Inhibitors: PRR 122.8 (105.2–143.3) | Not in label — unassessed | serious PRR 12.5 · 83% consumer | not reported in cached trials |
| Radiation injury | 51 | 11.1 8.4–14.7ROR 11.1 · calibrated p 0.025 ✓ | 10.2 EB05 8.0 · IC025 +2.8 3/3 methods agree vs other Kinase Inhibitors: PRR 220.0 (121.8–397.3) | Not in label — unassessed | serious n=38 | NCT02513394: 1/2,841 (0.0%) on Palbociclib |
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 |
|---|---|---|---|
| Neutropenia / agranulocytosis | 9,291 | 8.68.4–8.8 | signal |
| Thrombocytopenia | 3,755 | 3.83.7–3.9 | signal |
| Anaemia | 3,949 | 2.92.8–3.0 | signal |
| Osteonecrosis | 583 | 2.22.1–2.4 | signal |
| Interstitial lung disease | 755 | 1.71.6–1.9 | raised |
| Venous thromboembolism | 1,440 | 1.51.4–1.6 | raised |
| Serious infection | 4,066 | 1.21.1–1.2 | raised |
| Liver injury | 1,531 | 1.11.1–1.2 | raised |
| Fall / fracture | 1,637 | 1.00.9–1.0 | lower than other drugs |
| Depression | 1,138 | 0.90.8–0.9 | lower than other drugs |
| Kidney injury | 1,684 | 0.80.8–0.9 | lower than other drugs |
| Hyponatraemia | 289 | 0.80.7–0.9 | lower than other drugs |
| Malignancy | 1,287 | 0.80.7–0.8 | lower than other drugs |
| Opportunistic infection | 439 | 0.70.6–0.8 | lower than other drugs |
| Stroke | 797 | 0.70.7–0.8 | lower than other drugs |
| Hyperglycaemia / diabetes | 1,091 | 0.70.7–0.7 | lower than other drugs |
Trial evidence (ClinicalTrials.gov)
✓ Trial adverse-event data found on ClinicalTrials.gov
Largest completed trials with posted results that list Palbociclib 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 (19 of 40 signal terms matched).
- NCT02513394 — PALbociclib CoLlaborative Adjuvant Study (N=5796, PHASE3; 2029 AE terms posted; arms: Palbociclib Plus Endocrine Therapy (Arm ; Endocrine Therapy Alone (Arm B))
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) | 15,729 | 4.6 4.5–4.6ROR 5.3 · calibrated p 0.208 | 4.5 EB05 4.4 · IC025 +2.1 3/3 methods agree vs other Kinase Inhibitors: PRR 35.9 (35.4–36.5) | Labeled adverse reaction exact term | age-adj. PRR 4.5 · serious PRR 4.0 | NCT02513394: 2/2,841 (0.1%) on Palbociclib (serious AE) |
| White blood cell count decreased | 11,437 | 26.0 25.5–26.5ROR 29.4 · calibrated p 3e-4 ✓ | 23.3 EB05 23.0 · IC025 +4.5 3/3 methods agree vs other Kinase Inhibitors: PRR 190.5 (183.9–197.3) | Labeled adverse reaction exact term | age-adj. PRR 23.2 · serious PRR 16.5 | NCT02513394: 1/2,841 (0.0%) on Palbociclib (serious AE) |
| Neoplasm progression | 10,619 | 96.0 93.9–98.1ROR 108.0 · calibrated p 6e-8 ✓ | 66.9 EB05 65.8 · IC025 +6.0 3/3 methods agree vs other Kinase Inhibitors: PRR 109.1 (106.0–112.4) | Not in label — unassessed | age-adj. PRR 82.0 · serious PRR 46.4 | not reported in cached trials |
| Nausea | 8,548 | 2.4 2.4–2.5ROR 2.6 · calibrated p 0.791 | 2.4 EB05 2.4 · IC025 +1.2 3/3 methods agree vs other Kinase Inhibitors: PRR 31.3 (30.6–32.0) | Labeled adverse reaction exact term | age-adj. PRR 2.4 · serious PRR 2.3 | NCT02513394: 1/2,841 (0.0%) on Palbociclib (serious AE) |
| Death | 7,897 | 2.0 2.0–2.1ROR 2.1 · calibrated p 0.986 | 2.0 EB05 2.0 · IC025 +1.0 vs other Kinase Inhibitors: PRR 11.6 (11.4–11.9) | Outcome field, not a reaction | age-adj. PRR 1.8 · serious PRR 2.2 | NCT02513394: 2/2,841 (0.1%) on Palbociclib (serious AE) |
| Neutropenia (low neutrophils (infection-fighting cells)) | 6,728 | 11.5 11.2–11.8ROR 12.3 · calibrated p 0.015 ✓ | 11.0 EB05 10.8 · IC025 +3.4 3/3 methods agree vs other Kinase Inhibitors: PRR 96.9 (93.4–100.5) | Labeled adverse reaction exact term | age-adj. PRR 8.6 · serious PRR 11.8 | NCT02513394: 13/2,841 (0.5%) on Palbociclib (serious AE) |
| Alopecia (hair loss) | 6,369 | 7.4 7.2–7.5ROR 7.8 · calibrated p 0.071 | 7.2 EB05 7.0 · IC025 +2.8 3/3 methods agree vs other Kinase Inhibitors: PRR 95.1 (91.6–98.7) | Labeled adverse reaction exact term | age-adj. PRR 8.6 · serious PRR 6.4 | NCT02513394: 510/2,841 (18.0%) on Palbociclib |
| Diarrhoea (diarrhea) | 5,984 | 2.1 2.0–2.1ROR 2.1 · calibrated p 0.982 | 2.1 EB05 2.0 · IC025 +1.0 3/3 methods agree vs other Kinase Inhibitors: PRR 13.2 (12.8–13.5) | Labeled adverse reaction exact term | age-adj. PRR 1.8 · serious PRR 1.9 | NCT02513394: 2/2,841 (0.1%) on Palbociclib (serious AE) |
| Asthenia (weakness) | 3,797 | 2.2 2.2–2.3ROR 2.3 · calibrated p 0.904 | 2.2 EB05 2.2 · IC025 +1.1 3/3 methods agree vs other Kinase Inhibitors: PRR 19.2 (18.6–19.9) | Labeled adverse reaction exact term | age-adj. PRR 1.9 · serious PRR 2.2 | NCT02513394: 1/2,902 (0.0%) on Palbociclib (serious AE) |
| Off label use (used outside approved label) | 3,669 | 0.9 0.9–1.0ROR 0.9 · calibrated p 0.263 | 0.9 EB05 0.9 · IC025 -0.2 PRR-only: not supported by EBGM or IC vs other Kinase Inhibitors: PRR 7.3 (7.0–7.5) | Reporting / coding artifact | age-adj. PRR 1.0 · serious PRR 1.0 | not reported in cached trials |
| Decreased appetite (loss of appetite) | 3,488 | 3.4 3.3–3.5ROR 3.5 · calibrated p 0.495 | 3.3 EB05 3.2 · IC025 +1.7 3/3 methods agree vs other Kinase Inhibitors: PRR 19.9 (19.2–20.6) | Labeled adverse reaction exact term | age-adj. PRR 2.9 · serious PRR 3.1 | NCT02513394: 1/2,841 (0.0%) on Palbociclib |
| Pain | 3,483 | 1.3 1.2–1.3ROR 1.3 · calibrated p 0.483 | 1.3 EB05 1.2 · IC025 +0.3 vs other Kinase Inhibitors: PRR 25.6 (24.7–26.6) | Labeled adverse reaction exact term | age-adj. PRR 1.5 · serious PRR 1.2 | NCT02513394: 2/2,841 (0.1%) on Palbociclib (serious AE) |
| Malaise (feeling unwell) | 3,353 | 1.7 1.6–1.7ROR 1.7 · calibrated p 0.780 | 1.7 EB05 1.6 · IC025 +0.7 vs other Kinase Inhibitors: PRR 26.7 (25.7–27.7) | Not in label — unassessed | age-adj. PRR 1.7 · serious PRR 1.6 | NCT02513394: 32/2,841 (1.1%) on Palbociclib |
| Dyspnoea (shortness of breath) | 3,293 | 1.3 1.2–1.3ROR 1.3 · calibrated p 0.508 | 1.3 EB05 1.3 · IC025 +0.3 vs other Kinase Inhibitors: PRR 19.2 (18.5–20.0) | Labeled adverse reaction exact term | age-adj. PRR 1.1 · serious PRR 1.4 | NCT02513394: 2/2,841 (0.1%) on Palbociclib (serious AE) |
| Vomiting | 3,161 | 1.5 1.4–1.5ROR 1.5 · calibrated p 0.649 | 1.5 EB05 1.4 · IC025 +0.5 vs other Kinase Inhibitors: PRR 18.7 (18.0–19.5) | Labeled adverse reaction exact term | age-adj. PRR 1.5 · serious PRR 1.5 | NCT02513394: 2/2,841 (0.1%) on Palbociclib (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.
- Body surface area increased — n=41, PRR 102.4
- Pik3ca-activated mutation — n=102, PRR 100.7
- Neoplasm progression — n=10,619, PRR 96.0
- Pseudocirrhosis — n=47, PRR 36.9
- Metastases to eye — n=30, PRR 34.7 (also seen in trial arm)
- Second primary malignancy — n=686, PRR 19.8 (also seen in trial arm)
- Metastases to chest wall — n=28, PRR 19.4
- Neoplasm recurrence — n=242, PRR 16.9
- Metastases to bone — n=1,106, PRR 16.0 (also seen in trial arm)
- Metastases to skin — n=66, PRR 15.2
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 Palbociclib?
In FDA FAERS, the most frequently co-reported reaction terms for Palbociclib are fatigue, white blood cell count decreased, neoplasm progression, nausea, neutropenia, alopecia. 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 Palbociclib have an FDA boxed warning?
No. The FDA label retrieved for Palbociclib has no boxed warning; see the label's Warnings and Precautions for the recognised risks.
Do FAERS signals prove that Palbociclib 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 e0e6412f-50b4-4fd4-9364-62818d121a07, effective 20260702; matched on
openfda.generic_name.exact:"PALBOCICLIB") - 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, 1,171 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
PALBOCICLIB, 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.