A Study of Long-term Effect of Dupilumab on Skin Barrier Function in Pediatric Participants With Atopic Dermatitis

Study Overview
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Brief Summary
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This is a 2-year, open-label, exploratory study with a 4-week screening period and a 104-week treatment phase designed to investigate dupilumab's long-term effect on skin barrier function as measured by transepidermal water loss (TEWL) before and after skin tape stripping (STS) in approximately 48 pediatric participants (aged ≥6 and <14 years at study entry) with moderate-to-severe AD. After the 104-week treatment phase and the last assessment at the EndofTreatment (EOT) visit (as planned at Week 104), participants will be followed-up for 4 weeks and an End-of-Study (EoS) by telephone at 4 weeks after the EOT visit will end the study for each participant. The maximum duration of the study per participant will be 112 weeks (including screening period). TEWL assessment in predefined lesional and non-lesional skin areas before and after STS will be conducted every 3 months (every 13 weeks) during the treatment period from Day 1 (Baseline/Week 0, Visit 2) to Week 104 (Visit 10/EoT).

Detailed Description
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Study duration for each participant will be approximately 112 weeks, including: Screening period: Up to 4 weeks (Day -28 to Day -1) from signing the informed consent. Open-label dupilumab treatment period: 104 weeks (from Day 1/Week 0 to Week 104). Follow-up period: 4 weeks (safety follow-up phone visit at 4 weeks after the EoT visit).

Official Title
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A Two-year, Phase 4, Open-label, Single-arm Treatment Study to Evaluate the Long-term Effect of Dupilumab on Skin Barrier Function in Pediatric Participants (≥6 to <14 Years of Age) With Moderate-to-severe Atopic Dermatitis

Conditions
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Dermatitis Atopic

Intervention / Treatment
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* Drug: dupilumab


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age For new participants: ≥6 to <12 years of age (inclusive), at the time of signing the informed consent. For former PELISTAD participants: ≥6 to <14 years of age at the time of signing the informed consent. Type of participant and disease characteristics With AD diagnosis according to Hanifin and Rajka criteria at least 1 year before screening. Applicable to new participants only: Investigator Global Assessment score of ≥3 (for US participants) or IGA ≥4 (for EU participants) at screening (on the 0 to 4 scale) depending on approved IGA label indication in the country. Applicable to new participants only: Have active lesions on the upper limbs or lower limbs (including trunk, if needed), with severity for lesion erythema or edema/papulation ≥2 at screening on the 0 to 3 scale of the ISS. Applicable to new participants only: Should have a non-lesional (normal looking) skin area 4 cm from the edge of the lesional area. If unable to identify non-lesional skin 4 cm from the lesional area, it is acceptable to identify normal looking skin as close to the lesion as possible. Willing to refrain from applying any topical medications on the target assessment areas (including lesional and non-lesional) throughout the study until EoS unless necessary to alleviate intolerable symptoms. Willing and able to comply with all clinic visits and study-related procedures. Weight -Body weight ≥15 kg at screening. - - - Exclusion Criteria: Medical conditions Skin conditions other than AD that can confound assessments in the area of TEWL assessments in the opinion of the Investigator (ie, skin atrophy, ichthyosis, tinea infection, contact dermatitis). Cracked, crusted, oozing, or bleeding AD lesions in the designated lesional assessment area leaving insufficient skin that is adequate for TEWL assessments. Hypersensitivity to the active substance or to any of the excipients of dupilumab. Ocular disorder that in the opinion of the Investigator could adversely affect the individual's risk for study participation. Severe concomitant illness(es) that, in the Investigator's judgment, would adversely affect the participant's participation in the study. History of hypersensitivity reaction to skin tape or adhesives used in desquamme discs. Prior/concomitant therapy Treatment with any investigational medication other than dupilumab within 16 weeks or within 5 half-lives (if known) prior to Day 1, whichever is longer. Systemic AD treatment, cyclosporine A (CsA), systemic corticosteroids, azathioprine (AZA), methotrexate (MTX), mycophenolate mofetil (MMF), or Janus kinase (JAK) inhibitors or phototherapy within 4 weeks of baseline. Topical AD treatment within 1 week of baseline. Face and neck may be treated with topical steroids during the washout period if approved by the Investigator. Participants who received a live vaccine within 4 weeks of baseline. Prior/concurrent clinical study experience Current participation in another investigational or interventional clinical study. The above information is not intended to contain all considerations relevant to a potential participation in a clinical trial.

Ages Eligible for Study
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Minimum Age: 6 Years
Maximum Age: 13 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
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Pediatric AD participants<br>Participants will receive dupilumab IMP according to the approved prescribing label in the country/region where the study is conducted. | Drug: dupilumab<br>* solution for injection; by subcutaneous (SC) injection<br>* Other names: REGN668;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percent change from baseline in TEWL after 5 STS assessed on lesional skin. | Percent change from baseline in TEWL after 5 STS assessed on lesional skin. | Baseline to Week 104 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes from baseline (percent and absolute) in TEWL after 5, 10, 15, and 20 STS. | Changes from baseline (percent and absolute) in TEWL after 5, 10, 15, and 20 STS, respectively, assessed on lesional skin at each study visit | Baseline to Week 104 | 
| Incidence of treatment-emergent adverse events (TEAEs) or serious adverse events (SAEs) during the study. |  | Baseline to Week 108 |