JAK1 Inhibitor With Medicated Topical Therapy in Adolescents With Atopic Dermatitis

Study Overview
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Brief Summary
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This is a randomized, double blind, placebo controlled, parallel group, Phase 3 study to evaluate the efficacy and safety of PF 04965842 in adolescent participants 12 to <18 years of age with moderate to severe AD.

Detailed Description
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This is a randomized, double blind, placebo controlled, parallel group, Phase 3 study to evaluate the efficacy and safety of PF 04965842 in adolescent participants 12 to <18 years of age with moderate to severe AD. Participants will be screened within 28 days prior to the first dose of study intervention to confirm study eligibility. Subjects must have moderate-severe AD involving at least 10% Body Surface Area (BSA); an Investigator Global Assessment (IGA) score of at least 3; an Eczema Area Severity Index (EASI) of at least 16 and Peak Pruritus Numerical Rating Score (NRS) of at least 4 on baseline/Day 1. Eligible subjects will be randomized at the Baseline/Day 1 visit. Approximately 225 participants will be randomized in a 1:1:1 ratio to receive once daily PF 04965842 at 200 mg, 100 mg, or placebo for 12 weeks. Randomization will be stratified by baseline disease severity (moderate [IGA = 3] vs. severe [IGA = 4] AD). The investigational products will be administered QD for 12 weeks. Background therapy (medicated and non-medicated topical therapy) must be applied BID for the duration of the treatment period. The co-primary efficacy endpoints are an IGA score of clear (0) or almost clear (1) with a reduction from baseline of greater than 2 points at Week 12 AND an at least 75% improvement of the EASI score (EASI-75) at week 12. Safety and efficacy assessments will be conducted at the investigator site by a clinical assessor blinded to treatment assignment. Scheduled clinic or telephone study visits for all subjects will occur at Screening, Baseline/Day 1, Day 8 (by phone), Day 15, Day 29, Day 43 (by phone), Day 57, Day 85 (End of treatment/Early termination), Day 113 (End of Study). Participants discontinuing early from the study will undergo a 4 week follow up period. This study includes an immunogenicity sub study integrated into the last 4 weeks of the main study treatment period. At Week 8, up to approximately 90 participants (up to approximately 30 in each treatment arm) who have completed 8 weeks of treatment with study intervention will receive a tetanus, diphtheria and acellular pertussis combination vaccine (Tdap), and collection of blood samples for the evaluation of immunogenicity at Weeks 8 and 12. Participants of this sub study will complete all other protocol specified procedures in the main study. At the end of the 12 week study treatment, qualified participants completing the study will have the option to enter the long term extension (LTE) study B7451015.

Official Title
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A PHASE 3, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED, MULTI-CENTER STUDY INVESTIGATING THE EFFICACY AND SAFETY OF PF-04965842 CO-ADMINISTERED WITH BACKGROUND MEDICATED TOPICAL THERAPY IN ADOLESCENT PARTICIPANTS 12 TO <18 YEARS OF AGE WITH MODERATE-TO-SEVERE ATOPIC DERMATITIS

Conditions
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Atopic Dermatitis

Intervention / Treatment
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* Drug: Placebo
* Drug: PF-04965842
* Drug: PF04965842


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged between 12 and to 17 with a minimum body weight of 40 kg Diagnosis of atopic dermatitis (AD) for at least 1 year and current status of moderate to severe disease (>= the following scores: BSA 10%, IGA 3, EASI 16, Pruritus NRS severity 4) Exclusion Criteria: Acute or chronic medical or laboratory abnormality that may increase the risk associated with study participation Unwilling to discontinue current AD medications prior to the study or require treatment with prohibited medications during the study Prior treatment with JAK inhibitors Other active non-AD inflammatory skin diseases or conditions affecting skin Medical history including thrombocytopenia, coagulopathy or platelet dysfunction, malignancies, current or history of certain infections, lymphoproliferative disorders and other medical conditions at the discretion of the investigator Pregnant or breastfeeding women, or women of childbearing potential who are unwilling to use contraception

Ages Eligible for Study
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Minimum Age: 12 Years
Maximum Age: 17 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br>Placebo | Drug: Placebo<br>* Placebo<br>|
| Experimental: PF-04965842 100 mg QD<br>active | Drug: PF-04965842<br>* 100 mg QD<br>|
| Experimental: PF-04965842 200 mg QD<br>active | Drug: PF04965842<br>* 200 mg QD<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Participants Achieving Investigator's Global Assessment (IGA) Response of 'Clear' (0) or 'Almost Clear' (1) and ≥2 Points Improvement From Baseline at Week 12 | The IGA of Atopic Dermatitis (AD) was scored on a 5-point scale (0-4), reflecting a global consideration of the erythema, induration and scaling. The overall severity of AD was assessed according to the 5-point scale: 0=Clear, 1=Almost Clear, 2=Mild, 3=Moderate, and 4=Severe. Participants who withdrew from the study were counted as non-responder. | Baseline to Week 12 | 
| Percentage of Participants Achieving Eczema Area and Severity Index (EASI) Response ≥ 75% Improvement From Baseline at Week 12 | The EASI quantifies the severity of AD based on both severity of lesion clinical signs and the percent of body surface area (BSA) affected. The EASI score can vary in increments of 0.1 and range from 0.0 to 72.0, with higher scores representing greater severity of AD. Participants who withdrew from the study were counted as non-responder. | Baseline to Week 12 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of Participants Achieving ≥4 Points Improvement From Baseline in Peak Pruritis Numeric Rating Scale (PP-NRS) for Severity of Pruritus at Weeks 2, 4 and 12 | PP-NRS assesses the severity of itch (pruritus) due to AD. Participants were asked to assess their worst itching due to AD on an NRS anchored by the terms no itch (0) and worst itch imaginable (10). Participants who withdrew from the study were counted as non-responder. | Baseline, Weeks 2, 4 and 12 | 
| Change From Baseline in Pruritus and Symptoms Assessment for Atopic Dermatitis (PSAAD) at Week 12 | The PSAAD is a daily patient reported symptom diary presented as a 15 item questionnaire that includes 11 items developed to measure symptoms of AD, along with 4 additional items for exploratory and psychometric validation purposes (Sleep & Usual Activities Questions and Patient Global Impression of Severity & Patient Global Impression of Change Questions). Participants answer each question about skin condition based on a 24 hour recall. Each question was evaluated on a 11-point scale ranging from 0 to 10, where higher scores indicate more impact on skin condition.The PSAAD total score is calculated as the average of the responses to each of the 11 items and ranges from 0 (none) to 10 (extreme), where higher scores indicate worse severity of AD symptoms. | Baseline to Week 12 | 
| Percentage of Participants Achieving IGA Response of 'Clear' or 'Almost Clear' and ≥2 Points Improvement From Baseline at All Scheduled Time Points Except Week 12 | The IGA of AD is scored on a 5-point scale (0-4), reflecting a global consideration of the erythema, induration and scaling. The overall severity of AD was assessed according to the 5-point scale: 0=Clear, 1=Almost Clear, 2=Mild, 3=Moderate, and 4=Severe. Participants who withdrew from the study were counted as non-responder. | Baseline, Weeks 2, 4 and 8 | 
| Percentage of Participants Achieving EASI Response ≥ 75% Improvement From Baseline at All Scheduled Time Points Except Week 12 | The EASI quantifies the severity of AD based on both severity of lesion clinical signs and the percent of BSA affected. The EASI score can vary in increments of 0.1 and range from 0.0 to 72.0, with higher scores representing greater severity of AD. Participants who withdrew from the study were counted as non-responder. | Baseline, Weeks 2, 4 and 8 | 
| Percentage of Participants Achieving EASI Response ≥ 50% Improvement From Baseline | The EASI quantifies the severity of AD based on both severity of lesion clinical signs and the percent of BSA affected. The EASI score can vary in increments of 0.1 and range from 0.0 to 72.0, with higher scores representing greater severity of AD. Participants who withdrew from the study were counted as non-responder. | Baseline, Weeks 2, 4, 8 and 12 | 
| Percentage of Participants Achieving EASI Response ≥ 90% Improvement From Baseline | The EASI quantifies the severity of AD based on both severity of lesion clinical signs and the percent of BSA affected. The EASI score can vary in increments of 0.1 and range from 0.0 to 72.0, with higher scores representing greater severity of AD. Participants who withdrew from the study were counted as non-responder. | Baseline, Weeks 2, 4, 8 and 12 | 
| Percentage of Participants Achieving EASI Response =100% Improvement From Baseline | The EASI quantifies the severity of AD based on both severity of lesion clinical signs and the percent of BSA affected. The EASI score can vary in increments of 0.1 and range from 0.0 to 72.0, with higher scores representing greater severity of AD. Participants who withdrew from the study were counted as non-responder. | Baseline, Weeks 2, 4, 8 and 12 | 
| Percent Change From Baseline in EASI Score | The EASI quantifies the severity of AD based on both severity of lesion clinical signs and the percent of BSA affected. The EASI score can vary in increments of 0.1 and range from 0.0 to 72.0, with higher scores representing greater severity of AD. Participants who withdrew from the study were counted as non-responder. | Baseline, Weeks 2, 4, 8 and 12 | 
| Percentage of Participants Achieving ≥4 Points Improvement From Baseline in PP-NRS for Severity of Pruritus at All Scheduled Time Points Other Than Weeks 2, 4 and 12 | PP-NRS assesses the severity of itch (pruritus) due to AD. Participants were asked to assess their worst itching due to AD on an NRS anchored by the terms no itch (0) and worst itch imaginable (10). Participants who withdrew from the study were counted as non-responder. | Baseline, Days 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 and 15 | 
| Time to First Achieve ≥4 Points Improvement From Baseline in PP-NRS for Severity of Pruritus | PP-NRS assesses the severity of itch (pruritus) due to AD. Participants were asked to assess their worst itching due to AD on an NRS anchored by the terms no itch (0) and worst itch imaginable (10). | Baseline to Week 16 | 
| Percent Change From Baseline in PP-NRS for Severity of Pruritus | PP-NRS assesses the severity of itch (pruritus) due to AD. Participants were asked to assess their worst itching due to AD on an NRS anchored by the terms no itch (0) and worst itch imaginable (10). | Baseline, Days 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 | 
| Change From Baseline in Percentage Body Surface Area (BSA) | BSA efficacy is derived from the sum of the BSA in handprints across 4 body regions assessed as part of the EASI assessment. Handprint refers to that of each individual participant for their own measurement. The BSA efficacy ranges from 0 to 100%, with higher values representing greater severity of AD. The percentage BSA ranges from 0 to 100, with higher scores representing greater severity of AD. Since the scalp, palms, and soles were excluded from the BSA (efficacy) assessment, the maximum possible percentage BSA was less than 100. | Baseline, Weeks 2, 4, 8 and 12 | 
| Percent Change From Baseline in Percentage BSA | BSA efficacy is derived from the sum of the BSA in handprints across 4 body regions assessed as part of the EASI assessment. Handprint refers to that of each individual participant for their own measurement. The BSA efficacy ranges from 0 to 100%, with higher values representing greater severity of AD. The percentage BSA ranges from 0 to 100, with higher scores representing greater severity of AD. Since the scalp, palms, and soles were excluded from the BSA (efficacy) assessment, the maximum possible percentage BSA was less than 100. | Baseline, Weeks 2, 4, 8 and 12 | 
| Percentage of Participants Achieving Percentage BSA < 5% at Week 12 | BSA efficacy is derived from the sum of the BSA in handprints across 4 body regions assessed as part of the EASI assessment. Handprint refers to that of each individual participant for their own measurement. The BSA efficacy ranges from 0 to 100%, with higher values representing greater severity of AD. The percentage BSA ranges from 0 to 100, with higher scores representing greater severity of AD. Since the scalp, palms, and soles were excluded from the BSA (efficacy) assessment, the maximum possible percentage BSA was less than 100. | Baseline to Week 12 | 
| Percentage of Participants Achieving Scoring Atopic Dermatitis (SCORAD) Response ≥ 50% Improvement From Baseline | SCORAD is a validated scoring index for AD,which combines extent (0-100),severity (0-18),and subjective symptoms (0-20) based on pruritus and sleep loss,each scored (0-10). Extent,denoted as A,is measured by BSA affected by AD as a percentage of the whole BSA.The score for each body region is added up to determine A (maximum of 100).Severity, denoted as B,consists of the severity of several signs.Each is assessed as none(0),mild(1),moderate(2) or severe(3).The severity scores are added together to give B (maximum of 18).Subjective symptoms,denoted as C,are each scored by the participant using a NRS where 0 is no itch (or no sleeplessness) and 10 is the worst imaginable itch (or sleeplessness).These scores are added to give 'C' (maximum of 20).SCORAD for an individual is calculated by the formula: A/5 + 7B/2 + C (can range from 0 to 103).Higher values of SCORAD represent worse outcome. | Baseline, Weeks 2, 4, 8 and 12 | 
| Percentage of Participants Achieving SCORAD Response ≥ 75% Improvement From Baseline | SCORAD is a validated scoring index for AD,which combines extent (0-100),severity (0-18),and subjective symptoms (0-20) based on pruritus and sleep loss,each scored (0-10). Extent,denoted as A,is measured by BSA affected by AD as a percentage of the whole BSA.The score for each body region is added up to determine A (maximum of 100).Severity, denoted as B,consists of the severity of several signs.Each is assessed as none(0),mild(1),moderate(2) or severe(3).The severity scores are added together to give B (maximum of 18).Subjective symptoms,denoted as C,are each scored by the participant using a NRS where 0 is no itch (or no sleeplessness) and 10 is the worst imaginable itch (or sleeplessness).These scores are added to give 'C' (maximum of 20).SCORAD for an individual is calculated by the formula: A/5 + 7B/2 + C (can range from 0 to 103).Higher values of SCORAD represent worse outcome. | Baseline, Weeks 2, 4, 8 and 12 | 
| Change From Baseline in SCORAD Total Score | SCORAD is a validated scoring index for AD,which combines extent (0-100),severity (0-18),and subjective symptoms (0-20) based on pruritus and sleep loss,each scored (0-10). Extent,denoted as A,is measured by BSA affected by AD as a percentage of the whole BSA.The score for each body region is added up to determine A (maximum of 100).Severity, denoted as B,consists of the severity of several signs.Each is assessed as none(0),mild(1),moderate(2) or severe(3).The severity scores are added together to give B (maximum of 18).Subjective symptoms,denoted as C,are each scored by the participant using a NRS where 0 is no itch (or no sleeplessness) and 10 is the worst imaginable itch (or sleeplessness).These scores are added to give 'C' (maximum of 20).SCORAD for an individual is calculated by the formula: A/5 + 7B/2 + C (can range from 0 to 103).Higher values of SCORAD represent worse outcome. | Baseline, Weeks 2, 4, 8 and 12 | 
| Percent Change From Baseline in SCORAD Total Score | SCORAD is a validated scoring index for AD,which combines extent (0-100),severity (0-18),and subjective symptoms (0-20) based on pruritus and sleep loss,each scored (0-10). Extent,denoted as A,is measured by BSA affected by AD as a percentage of the whole BSA.The score for each body region is added up to determine A (maximum of 100).Severity, denoted as B,consists of the severity of several signs.Each is assessed as none(0),mild(1),moderate(2) or severe(3).The severity scores are added together to give B (maximum of 18).Subjective symptoms,denoted as C,are each scored by the participant using a NRS where 0 is no itch (or no sleeplessness) and 10 is the worst imaginable itch (or sleeplessness).These scores are added to give 'C' (maximum of 20).SCORAD for an individual is calculated by the formula: A/5 + 7B/2 + C (can range from 0 to 103).Higher values of SCORAD represent worse outcome. | Baseline, Weeks 2, 4, 8 and 12 | 
| Change From Baseline in SCORAD Subjective Visual Analogue Scale (VAS) of Sleep Loss | SCORAD is a validated scoring index for AD, which combines extent (A, 0-100), severity (B, 0-18), and subjective symptoms (C, 0-20) based on pruritus and sleep loss, each scored (0-10). The SCORAD for an individual is calculated by the formula: A/5 + 7B/2 + C (can range from 0 to 103). Subjective symptoms (ie, itch and sleep loss) are each scored by the participant using a VAS where 0 is no itch (or no sleep loss) and 10 is the worst imaginable itch (or sleep loss). The value for each should reflect the average on a 10 point scale for the last 3 days/nights. Changes from baseline in SCORAD subjective assessments of itch were not evaluated. Only changes from baseline in SCORAD subjective assessments of sleep loss are presented below. | Baseline, Weeks 2, 4, 8 and 12 | 
| Percent Change From Baseline in SCORAD Subjective VAS of Sleep Loss | SCORAD is a validated scoring index for AD, which combines extent (A, 0-100), severity (B, 0-18), and subjective symptoms (C, 0-20) based on pruritus and sleep loss, each scored (0-10). The SCORAD for an individual is calculated by the formula: A/5 + 7B/2 + C (can range from 0 to 103). Subjective symptoms (ie, itch and sleep loss) are each scored by the participant using a VAS where 0 is no itch (or no sleep loss) and 10 is the worst imaginable itch (or sleep loss). The value for each should reflect the average on a 10 point scale for the last 3 days/nights. Changes from baseline in SCORAD subjective assessments of itch were not evaluated. Only changes from baseline in SCORAD subjective assessments of sleep loss are presented below. | Baseline, Weeks 2, 4, 8 and 12 | 
| Number of Days When a Corticosteroid Not Used up to Day 88 |  | Baseline to Day 88 | 
| Change From Baseline in Children's Dermatology Life Quality Index (DLQI) | The DLQI is a general dermatology questionnaire that consists of 10 items to assess participant-reported health-related quality of life (daily activities, personal relationships, symptoms and feelings, leisure, work and school, and treatment).The DLQI is a psychometrically valid and reliable instrument that has been translated into several languages, and the DLQI total scores have been shown to be responsive to change. The minimally important difference for the DLQI has been estimated as a 3-5 point change from baseline. Each item is scored as very much (3), a lot (2), a little (1) and not at all (0). The score can range from 0 to 30. The higher values represent the worse dermatology life quality. Participants who withdrew from the study were counted as non-responder. | Baseline, Weeks 2, 4, 8 and 12 | 
| Percentage of Participants With ≥2.5 Points at Baseline and Achieving ≥2.5 Points Improvement From Baseline in Children's DLQI | The DLQI is a general dermatology questionnaire that consists of 10 items to assess participant-reported health-related quality of life (daily activities, personal relationships, symptoms and feelings, leisure, work and school, and treatment).The DLQI is a psychometrically valid and reliable instrument that has been translated into several languages, and the DLQI total scores have been shown to be responsive to change. The minimally important difference for the DLQI has been estimated as a 3-5 point change from baseline. Each item is scored as very much (3), a lot (2), a little (1) and not at all (0). The score can range from 0 to 30. The higher values represent the worse dermatology life quality. Participants who withdrew from the study were counted as non-responder. | Baseline, Weeks 2, 4, 8 and 12 | 
| Change From Baseline in Anxiety of Hospital Anxiety and Depression Scale (HADS) | The HADS is a 14-item patient reported outcome (PRO) measure used to detect states of anxiety and depression over the past week. Seven of the items relate to anxiety and seven relate to depression. Each item is scored from 0 to 3 which means a person can score between 0 to 21 for either anxiety or depression. Higher values represent worse outcome. | Baseline, Weeks 2, 4, 8 and 12 | 
| Change From Baseline in Depression of HADS | The HADS is a 14-item patient reported outcome (PRO) measure used to detect states of anxiety and depression over the past week. Seven of the items relate to anxiety and seven relate to depression. Each item is scored from 0 to 3 which means a person can score between 0 to 21 for either anxiety or depression. Higher values represent worse outcome. | Baseline, Weeks 2, 4, 8 and 12 | 
| Change From Baseline in Patient-Oriented Eczema Measure (POEM) | The POEM is a 7-item PRO measure used to assess the impact of AD over the past week. Each item is scored as no days (0), 1-2 days (1), 3-4 days (2), 5-6 days (3) and every day (4). The score ranges from 0 to 28. The higher values represent more severe AD. | Baseline, Weeks 2, 4, 8 and 12 | 
| Change From Baseline in Dermatitis Family Impact (DFI) at Week 12 | The DFI is a validated 10-item measure filled out by the parent/caregiver of the patient used to assess the impact of the patient's eczema on the family. The instrument has a recall period of 7 days. Each item is scored as very much (3), a lot (2), a little (1) or not at all (0). The score can range from 0 to 30. The higher values represent the worse impact. | Baseline to Week 12 | 
| Change From Baseline in Patient Global Assessment (PtGA) | The PtGA asked the participant to evaluate the overall cutaneous disease at that point in time on a single-item, 5-point scale. The same category labels used in the IGA were used for the PtGA, ie, severe (4), moderate (3), mild (2),almost clear (1), and clear (0). The PtGA was completed as per schedule of activities. | Baseline, Weeks 2, 4, 8 and 12 | 
| Percentage of Participants With ≥2 Points at Baseline and Achieving 'Clear' or 'Almost Clear' and ≥2 Points Improvement From Baseline in PtGA | The PtGA asked the participant to evaluate the overall cutaneous disease at that point in time on a single-item, 5-point scale. The same category labels used in the IGA were used for the PtGA, ie, severe (4), moderate (3), mild (2),almost clear (1), and clear (0). The PtGA was completed as per schedule of activities. | Baseline, Weeks 2, 4, 8 and 12 | 
| Change From Baseline in EuroQol Quality of Life 5-Dimension Youth Scale (EQ-5D-Y) VAS Score | The EQ-5D is a validated, standardized, generic instrument that is the most widely used preference based health related quality of life questionnaire in cost effectiveness and health technologies assessment. The EQ-5D-Y is a version of the instrument specifically developed and validated for use by youths aged 12 through 17 years. Components assess level of current health for 5 domains: mobility, self-care, usual activities, pain and discomfort, anxiety and depression. Score scale for each domain ranges from 1 (minimum) to 3 (maximum), with higher scores indicating worse health condition. In addition, respondents use a vertical, graduated Visual Analogue Scale (VAS) to rate their own health between 0 (the worst) and 100 (the best health state he/she can imagine). | Baseline, Weeks 2, 4, 8 and 12 | 
| Change From Baseline in Pediatric Functional Assessment of Chronic Illness Therapy Fatigue Scale (Peds-FACIT-F) at Week 12 | The Functional Assessment of Chronic Illness Therapy Fatigue Scale (FACIT-F) is a 13-item questionnaire. Participants scored each item on a 5-point scale: 0 (none of the time) to 4 (all of the time). Larger the participant's response to the questions (with the exception of 2 negatively stated), greater was the participant's fatigue. For all questions, except for the 2 negatively stated ones, the code was reversed and a new score was calculated as (4 minus the participant's response). The sum of all responses resulted in the FACIT-F score for a total possible score of 0 (worse score) to 52 (better score), with higher scores representing better overall health status (less fatigue). Changes from baseline at Week 12 are presented below. Changes from baseline at other scheduled time points were not evaluated. | Baseline to Week 12 | 
| Number of Participants With Treatment Emergent Adverse Events (TEAEs) | An adverse event (AE) was any untoward medical occurrence in a clinical investigation participant administered a product; the event did not need to have a causal relationship with the treatment. TEAEs were AEs that occurred following the start of treatment or AEs increasing in severity during treatment. Treatment-related TEAEs were determined by the investigator. | 16 weeks | 
| Number of Participants With Serious Adverse Events (SAEs) | A serious adverse event (SAE) was any untoward medical occurrence at any dose that resulted in death; was life threatening; required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent or significant disability/incapacity; resulted in congenital anomaly/birth defect. Treatment-related SAEs were determined by the investigator. | 16 weeks | 
| Number of Participants Who Discontinued From the Study Due to TEAEs | An AE was any untoward medical occurrence in a clinical investigation participant administered a product; the event did not need to have a causal relationship with the treatment. TEAEs were AEs that occurred following the start of treatment or AEs increasing in severity during treatment. Treatment-related TEAEs were determined by the investigator. | 16 weeks | 
| Number of Participants With Laboratory Test Abnormalities (Without Regard to Baseline Abnormality) | Laboratory tests included hematology (including coagulation panel), clinical chemistry, lipid profile panel, and routine urinalysis. LLN is lower limit of normal. ULN is upper limit of normal. | 16 weeks | 
| Number of Participants With Electrocardiogram (ECG) Data Meeting Prespecified Criteria | A 12-lead ECG was obtained using an ECG machine that automatically calculates the heart rate and measures PR, QRS, QT, and corrected QT intervals. All scheduled ECGs were performed after the participant had rested quietly for at least 10 minutes in a supine position. Reading of ECGs were performed by a central reader who has expertise reading and interpreting ECGs in adolescents. The QTcF interval is the only prespecified ECG criteria (Marked prolongation of the QTcF interval to >500 ms or >60 ms change from screening ECG); data are presented below. | 16 weeks | 
| Categorization of Vital Signs Data Meeting Prespecified Criteria | Vital signs (pulse rate, systolic and diastolic blood pressure) were obtained with participant in the seated position, after having sat calmly for at least 5 minutes. | 16 weeks | 
| Fold Increase of Immunoglobulin G (IgG) Concentrations Against Specific Vaccine Antigens at 4 Weeks Post-Vaccination | The immunogenicity analysis was to evaluate the effect of abrocitinib on immunogenicity to a tetanus, diphtheria and pertussis combination vaccine (Tdap) vaccine in adolescent participants 12 to <18 years of age with moderate to severe AD. Participants who completed 8 weeks of treatment with study intervention received Tdap at Week 8, and had blood samples collected for the evaluation of immunogenicity to the vaccine at Weeks 8 and 12. The fold increase was defined as the ratio (post-vaccination: pre-vaccination) of concentration values. The geometric mean fold rise (GMFR) is presented below, and was calculated by first arithmetically averaging the logarithmically transformed ratio (post-vaccination: pre-vaccination) values, and then back transformation. A 95% CI for GMFR was constructed by back transformation of the CI for the logarithmically transformed GMFRs computed using the Student's t distribution. | 4 weeks post-vaccination with Tdap (Week 12) | 
| Plasma PF-04965842 Concentration at Week 8 |  | 2 hours pre-dose at Week 8 | 
| Plasma PF-04965842 Concentration at Week 12 |  | 2 hours post-dose at Week 12 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Atopic Dermatitis, JAK1 inhibitor