Adults 18 to 70, any sex, with Hepatic Impairment. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
Maximum Observed Plasma Concentration (Cmax) for PF-04965842Primary· 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, 10, 14, 24, 36, 48, 72 hours post-dose in each cohort
Cmax is maximum plasma concentration. It was observed directly from data.
Group
Value
95% CI
PF-04965842 (Normal Hepatic Function Cohort)
1352
± 44
PF-04965842 (Mild Hepatic Impairment Cohort)
1276
± 41
PF-04965842 (Moderate Hepatic Impairment Cohort)
1426
± 63
Area Under the Plasma Concentration-Time Curve From Time Zero Extrapolated to Infinite Time (AUCinf) for PF-04965842Primary· 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, 10, 14, 24, 36, 48, 72 hours post-dose in each cohort
AUCinf is area under the concentration-time curve (AUC) from time 0 (pre-dose) extrapolated to infinite time.
Group
Value
95% CI
PF-04965842 (Normal Hepatic Function Cohort)
5587
± 74
PF-04965842 (Mild Hepatic Impairment Cohort)
7449
± 29
PF-04965842 (Moderate Hepatic Impairment Cohort)
8603
± 55
Unbound Cmax (Cmax,u) for Active MoietySecondary· 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, 10, 14, 24, 36, 48, 72 hours post-dose in each cohort
Cmax,u is unbound Cmax. The active moiety is comprised of parent drug PF-04965842, active metabolites PF-06471658 and PF-07055087.
Group
Value
95% CI
PF-04965842 (Normal Hepatic Function Cohort)
2390
± 20
PF-04965842 (Mild Hepatic Impairment Cohort)
1815
± 36
PF-04965842 (Moderate Hepatic Impairment Cohort)
2011
± 41
Unbound AUCinf (AUCinf,u) for Active MoietySecondary· 0 (pre-dose), 0.5, 1, 2, 3, 4, 6, 8, 10, 14, 24, 36, 48, 72 hours post-dose in each cohort
AUCinf,u is unbound AUCinf. The active moiety is comprised of parent drug PF-04965842, active metabolites PF-06471658 and PF-07055087.
Group
Value
95% CI
PF-04965842 (Normal Hepatic Function Cohort)
12010
± 40
PF-04965842 (Mild Hepatic Impairment Cohort)
11500
± 24
PF-04965842 (Moderate Hepatic Impairment Cohort)
13790
± 30
Number of Participants With Treatment-Emergent Adverse Events (AEs) for PF-04965842Secondary· From screening (within 28 days prior to Day 1) till up to 36 days post-dose, the total maximum duration was approximately 63 days for individual participants.
Treatment-related AE was any untoward medical occurrence attributed to study drug in a participant who received study drug. Treatment-emergent adverse events (TEAEs) were those with initial onset or increasing in severity between the first dose of investigational product and up to 36 days post-dose.
AEs (all causalities)
Group
Value
95% CI
PF-04965842 (Normal Hepatic Function Cohort)
2
PF-04965842 (Mild Hepatic Impairment Cohort)
3
PF-04965842 (Moderate Hepatic Impairment Cohort)
0
AEs (treatment related)
Group
Value
95% CI
PF-04965842 (Normal Hepatic Function Cohort)
1
PF-04965842 (Mild Hepatic Impairment Cohort)
3
PF-04965842 (Moderate Hepatic Impairment Cohort)
0
Number of Participants With Laboratory Test Abnormalities (Without Regard to Baseline Abnormality)Secondary· Screening (within 28 days prior to Day 1), Day -1, 2, 24, 72 hours post-dose.
Laboratory tests included tests that were performed under the categories of hematology, chemistry, urinalysis, other, and additional tests needed for Hy's law.
Group
Value
95% CI
PF-04965842 (Normal Hepatic Function Cohort)
4
PF-04965842 (Mild Hepatic Impairment Cohort)
7
PF-04965842 (Moderate Hepatic Impairment Cohort)
8
Number of Participants With Electrocardiogram (ECG) Findings of Potential Clinical Importance for PF-04965842Secondary· Screening (within 28 days prior to Day 1), Day -1, 2, 72 hours post-dose.
12-Lead ECGs were collected after the participants rested quietly for at least 10 minutes in a supine position. Clinical significance of ECG recordings was determined at the investigator's discretion.
Group
Value
95% CI
PF-04965842 (Normal Hepatic Function Cohort)
0
PF-04965842 (Mild Hepatic Impairment Cohort)
0
PF-04965842 (Moderate Hepatic Impairment Cohort)
0
Number of Participants With Vital Sign Findings of Potential Clinical Importance for PF-04965842Secondary· Screening (within 28 days prior to Day 1), 0 (pre-dose), and 72 hours post-dose.
Vital signs (pulse rate, systolic and diastolic blood pressure) were obtained with participant following at least 5 minutes of supine rest. Clinical significance of vital signs was determined at the investigator's discretion.
Group
Value
95% CI
PF-04965842 (Normal Hepatic Function Cohort)
0
PF-04965842 (Mild Hepatic Impairment Cohort)
0
PF-04965842 (Moderate Hepatic Impairment Cohort)
0
Adverse events — posted to ClinicalTrials.gov
Time frame: From screening (within 28 days prior to Day 1) till up to 36 days post-dose, the total maximum duration was approximately 63 days for individual participants..
Reporting threshold: 5%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
This is a Phase 1 non randomized, open label, single dose, parallel cohort study to investigate the effect of hepatic impairment on the PK, safety and tolerability of PF 04965842.
Publications & conference data
2 peer-reviewed publications reference this trial (live from Europe PMC):
NCT04099563 — Study to Assess Pharmacokinetics, Safety and Tolerability of PF-04965842 in Chinese Healthy Participants
· Phase 1
· completed
NCT03937258 — A Study to Assess Pharmacokinetics of PF-04965842 and Its Metabolites and Effect of Probenecid in Healthy Participants
· Phase 1
· completed
NCT03796676 — JAK1 Inhibitor With Medicated Topical Therapy in Adolescents With Atopic Dermatitis
· Phase 3
· completed
NCT03806101 — Study of PF-04965842 Effect on Rosuvastatin Pharmacokinetics in Healthy Participants
· Phase 1
· completed
NCT03796182 — Study of PF 04965842 Effect on MATE1/2K Activity in Healthy Participants
· Phase 1
· completed
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Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by Pfizer
Last refreshed: 18 May 2020
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT03626415.