Pirtobrutinib side effects: what 822 FDA adverse event reports show

Pirtobrutinib · Jaypirca · 16 reaction terms · 346 drug–reaction co-reports · data 2026-09-14

Drug class

Kinase Inhibitor

FDA label (Established Pharmacologic Class) · compare the class

Brand names

Jaypirca

openFDA label

Who reports

822 reports · 70% serious · 209 with death outcome · 34% female

openFDA FAERS counts, all years, deduplication not applied

Used for

JAYPIRCA ® is a kinase inhibitor indicated for the treatment of: Adult patients with relapsed or refractory mantle cell lymphoma (MCL) after at least two lines of systemic therapy, including a BTK inhibitor. ( 1.1 ). This indication is approved under accelerated approval based on response rate.

FDA label, Indications and Usage

What it is

Pirtobrutinib is a kinase inhibitor. It is an orally available, small molecule ATP-competitive inhibitor of BTK. The active pharmaceutical ingredient is pirtobrutinib with the molecular formula C 22 H 21 F 4 N 5 O 3 and a molecular weight of 479.44 g/mol.

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 16 strongest signals

Labeled adverse reaction 2Labeled (related wording) 1Likely indication confounding 2Reporting / coding artifact 3Lab value / disease marker 2Not in label — unassessed 6

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 flags pairs whose reports are unusually skewed by sex or come mostly from consumers rather than clinicians. 0 further terms are in the interactive explorer. Reaction links open the term's cross-drug page.

Show: hide coding/lab/outcome terms hide indication terms unlabeled only hide PRR-only

Reaction	Reports	PRR 95% CI · ROR · χ²/p	EBGM EB05 · IC025	Label screen	Serious-only & strata	Trial cross-check
Splenomegaly	24	52.3 35.3–77.6ROR 53.9 · χ² 1,156 / p 1e-253	50.3 EB05 35.5 · IC025 +4.0 3/3 methods agree	Not in label — unassessed	serious PRR 48.1	no trial data cached
Cytokine release syndrome	25	33.5 22.7–49.3ROR 34.5 · χ² 755 / p 2e-166	32.7 EB05 23.3 · IC025 +3.7 3/3 methods agree	Not in label — unassessed	serious PRR 27.7 · 92% clinician	no trial data cached
Lymphadenopathy	29	20.9 14.6–29.8ROR 21.6 · χ² 529 / p 2e-117	20.6 EB05 15.0 · IC025 +3.3 3/3 methods agree	Not in label — unassessed	serious PRR 20.8 · ♀ 12% (drug 34%) · 86% consumer	no trial data cached
Hypercalcaemia	9	18.6 9.7–35.6ROR 18.8 · χ² 133 / p 5e-31	17.0 EB05 8.3 · IC025 +2.1 3/3 methods agree	Not in label — unassessed	serious PRR 16.3	no trial data cached
Malignant neoplasm progression	74	18.5 14.9–23.0ROR 20.3 · χ² 1,214 / p 3e-266	18.4 EB05 15.2 · IC025 +3.7 3/3 methods agree	Reporting / coding artifact	serious PRR 15.5	no trial data cached
White blood cell count increased	27	17.9 12.3–25.9ROR 18.4 · χ² 414 / p 3e-92	17.6 EB05 12.6 · IC025 +3.1 3/3 methods agree	Lab value / disease marker	serious PRR 12.4	no trial data cached
Covid-19 pneumonia	8	17.2 8.6–34.2ROR 17.3 · χ² 106 / p 4e-25	15.0 EB05 6.7 · IC025 +1.9 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 14.3	no trial data cached
Pneumocystis jirovecii pneumonia	6	15.3 6.9–34.0ROR 15.4 · χ² 67 / p 2e-16	11.7 EB05 4.4 · IC025 +1.4 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 12.6	no trial data cached
Pancytopenia (all blood cells low)	32	14.6 10.4–20.6ROR 15.2 · χ² 394 / p 6e-88	14.3 EB05 10.4 · IC025 +3.0 3/3 methods agree	Labeled (related wording) related wording	serious PRR 12.1	no trial data cached
Blood lactate dehydrogenase increased	9	14.4 7.5–27.6ROR 14.5 · χ² 99 / p 1e-23	12.3 EB05 5.8 · IC025 +1.9 3/3 methods agree	Lab value / disease marker	serious PRR 12.6	no trial data cached
Leukaemia	5	13.5 5.6–32.4ROR 13.6 · χ² 46 / p 6e-12	9.1 EB05 3.4 · IC025 +1.1 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 11.1	no trial data cached
Disease progression	52	11.2 8.6–14.6ROR 11.9 · χ² 477 / p 4e-106	10.9 EB05 8.5 · IC025 +2.9 3/3 methods agree	Reporting / coding artifact	serious PRR 9.9 · 98% clinician	no trial data cached
Bone marrow failure	9	11.2 5.9–21.5ROR 11.3 · χ² 74 / p 4e-18	8.9 EB05 4.4 · IC025 +1.7 3/3 methods agree	Not in label — unassessed	serious PRR 9.2	no trial data cached
Lymphoma	6	9.9 4.4–21.9ROR 9.9 · χ² 39 / p 2e-10	6.7 EB05 3.0 · IC025 +1.1 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 8.2	no trial data cached
Therapy interrupted	18	6.6 4.2–10.5ROR 6.8 · χ² 81 / p 1e-19	5.8 EB05 3.8 · IC025 +1.7 3/3 methods agree	Reporting / coding artifact	serious PRR 3.5	no trial data cached
Prostate cancer	13	4.1 2.4–7.0ROR 4.1 · χ² 27 / p 9e-8	3.6 EB05 2.3 · IC025 +0.9 3/3 methods agree	Not in label — unassessed	serious PRR 3.3	no trial data cached

Trial evidence (ClinicalTrials.gov)

Trial cross-check not yet run for this drug (ClinicalTrials.gov pull covers the 800 most-reported drugs first).

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
Malignant neoplasm progression	74	18.5 14.9–23.0ROR 20.3 · χ² 1,214 / p 3e-266	18.4 EB05 15.2 · IC025 +3.7 3/3 methods agree	Reporting / coding artifact	serious PRR 15.5	no trial data cached
Disease progression	52	11.2 8.6–14.6ROR 11.9 · χ² 477 / p 4e-106	10.9 EB05 8.5 · IC025 +2.9 3/3 methods agree	Reporting / coding artifact	serious PRR 9.9 · 98% clinician	no trial data cached
Pancytopenia (all blood cells low)	32	14.6 10.4–20.6ROR 15.2 · χ² 394 / p 6e-88	14.3 EB05 10.4 · IC025 +3.0 3/3 methods agree	Labeled (related wording) related wording	serious PRR 12.1	no trial data cached
Lymphadenopathy	29	20.9 14.6–29.8ROR 21.6 · χ² 529 / p 2e-117	20.6 EB05 15.0 · IC025 +3.3 3/3 methods agree	Not in label — unassessed	serious PRR 20.8 · ♀ 12% (drug 34%) · 86% consumer	no trial data cached
White blood cell count increased	27	17.9 12.3–25.9ROR 18.4 · χ² 414 / p 3e-92	17.6 EB05 12.6 · IC025 +3.1 3/3 methods agree	Lab value / disease marker	serious PRR 12.4	no trial data cached
Cytokine release syndrome	25	33.5 22.7–49.3ROR 34.5 · χ² 755 / p 2e-166	32.7 EB05 23.3 · IC025 +3.7 3/3 methods agree	Not in label — unassessed	serious PRR 27.7 · 92% clinician	no trial data cached
Splenomegaly	24	52.3 35.3–77.6ROR 53.9 · χ² 1,156 / p 1e-253	50.3 EB05 35.5 · IC025 +4.0 3/3 methods agree	Not in label — unassessed	serious PRR 48.1	no trial data cached
Therapy interrupted	18	6.6 4.2–10.5ROR 6.8 · χ² 81 / p 1e-19	5.8 EB05 3.8 · IC025 +1.7 3/3 methods agree	Reporting / coding artifact	serious PRR 3.5	no trial data cached
Prostate cancer	13	4.1 2.4–7.0ROR 4.1 · χ² 27 / p 9e-8	3.6 EB05 2.3 · IC025 +0.9 3/3 methods agree	Not in label — unassessed	serious PRR 3.3	no trial data cached
Bone marrow failure	9	11.2 5.9–21.5ROR 11.3 · χ² 74 / p 4e-18	8.9 EB05 4.4 · IC025 +1.7 3/3 methods agree	Not in label — unassessed	serious PRR 9.2	no trial data cached
Blood lactate dehydrogenase increased	9	14.4 7.5–27.6ROR 14.5 · χ² 99 / p 1e-23	12.3 EB05 5.8 · IC025 +1.9 3/3 methods agree	Lab value / disease marker	serious PRR 12.6	no trial data cached
Hypercalcaemia	9	18.6 9.7–35.6ROR 18.8 · χ² 133 / p 5e-31	17.0 EB05 8.3 · IC025 +2.1 3/3 methods agree	Not in label — unassessed	serious PRR 16.3	no trial data cached
Covid-19 pneumonia	8	17.2 8.6–34.2ROR 17.3 · χ² 106 / p 4e-25	15.0 EB05 6.7 · IC025 +1.9 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 14.3	no trial data cached
Lymphoma	6	9.9 4.4–21.9ROR 9.9 · χ² 39 / p 2e-10	6.7 EB05 3.0 · IC025 +1.1 3/3 methods agree	Likely indication confounding term in indications; also in warnings	serious PRR 8.2	no trial data cached
Pneumocystis jirovecii pneumonia	6	15.3 6.9–34.0ROR 15.4 · χ² 67 / p 2e-16	11.7 EB05 4.4 · IC025 +1.4 3/3 methods agree	Labeled adverse reaction exact term	serious PRR 12.6	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.

Splenomegaly — n=24, PRR 52.3
Cytokine release syndrome — n=25, PRR 33.5
Lymphadenopathy — n=29, PRR 20.9

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 Pirtobrutinib?

In FDA FAERS, the most frequently co-reported reaction terms for Pirtobrutinib are pancytopenia, lymphadenopathy, white blood cell count increased, cytokine release syndrome, splenomegaly, prostate cancer. 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 Pirtobrutinib have an FDA boxed warning?

No. The FDA label retrieved for Pirtobrutinib has no boxed warning; see the label's Warnings and Precautions for the recognised risks.

Do FAERS signals prove that Pirtobrutinib 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 bd551845-0878-49a4-860f-839b83f6b801, effective 20260306; matched on openfda.generic_name.exact:"PIRTOBRUTINIB")
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, field patient.drug.openfda.generic_name.exact, 16 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.