The children will be randomly assigned to receive tralokinumab + TCS or placebo + TCS for the initial 16 weeks, with the treatment being double-blinded. During the first 16 weeks, children will have a 2 out of 3 chance of getting tralokinumab and a 1 out of 3 chance of getting placebo. Thereafter, all subjects will receive tralokinumab + TCS. The infants will receive tralokinumab + TCS as open-label treatment for the entire treatment period, meaning that the participants will know they are receiving tralokinumab. After stopping treatment, all participants will enter a 4-week safety follow-up period. conditions: Atopic Dermatitis studyType: INTERVENTIONAL phases: PHASE3 allocation: RANDOMIZED interventionModel: PARALLEL interventionModelDescription: The study design is parallel for children and a single group for infants. primaryPurpose: TREATMENT masking: TRIPLE maskingDescription: For subjects aged 2 to \<12 years at screening, the trial is double-blind to ensure an objective evaluation of efficacy and safety of the Investigational Medicinal Product (IMP). The subject, the subject's caregiver(s), and the investigator involved in the clinical evaluation and monitoring of the subjects will not be aware of the treatment from baseline to Week 16. However, the site staff that responsible for administering tralokinumab will be aware of the treatment allocation as tralokinumab is visibly different from placebo and has a higher viscosity, requiring more pressure to depress the plunger during injections. whoMasked: PARTICIPANT whoMasked: CARE_PROVIDER whoMasked: INVESTIGATOR count: 195 type: ESTIMATED name: Tralokinumab + TCS name: Placebo + TCS measure: Investigator's Global Assessment for atopic dermatitis (IGA 0/1) score of 0 (clear) or 1 (almost clear) in subjects aged 2 to <12 years at screening. measure: Having at least 75% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 2 to <12 years at screening. measure: Having at least 90% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 2 to <12 years at screening. measure: Having at least 90% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 6 month to <2 years at screening. measure: Investigator's Global Assessment for atopic dermatitis (IGA 0/1) score of 0 (clear) or 1 (almost clear) in subjects aged 6 month to <2 years at screening. measure: Having at least 75% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 6 month to <2 years at screening. measure: Having at least 50% reduction in EASI score in subjects aged 2 to <12 years at screening. measure: Having at least 50% reduction in EASI score in subjects aged 6 month to <2 years at screening. measure: Percent change in EASI in subjects aged 2 to <12 years at screening. measure: Percent change in EASI in subjects aged 6 month to <2 years at screening. measure: Percent change in Scoring Atopic Dermatitis (SCORAD) in subjects aged 2 to <12 years at screening. measure: Percent change in Scoring Atopic Dermatitis (SCORAD) in subjects aged 6 month to <2 years at screening. measure: Percent change in affected BSA in subjects aged 2 to <12 years at screening. measure: Percent change in affected BSA in subjects aged 6 month to <2 years at screening. measure: Percent change in Children's Dermatology Life Quality Index (CDLQI) for subjects aged 4 to <12 years at screening. measure: Reduction in Child Worst Itch numeric rating score (NRS) (weekly average) ≥4 for subjects aged 6 to <12 years at screening. measure: Reduction in Scratch Observer-Reported Outcome (ObsRO) (weekly average) ≥4 for subjects aged 2 to <6 years at screening. measure: Reduction in Scratch Observer-Reported Outcome (ObsRO) (weekly average) ≥4 for subjects aged 6 months to <2 years years at screening. measure: Reduction of ≥4 in Child Worst Itch NRS (weekly average) for subjects aged 6 to <12 years at screening or Scratch ObsRO (weekly average) for subjects aged 2 to <6 years at screening. measure: Percent change in Patient-Oriented Eczema Measure (POEM) in subjects aged 2 to <12 years at screening. measure: Percent change in Patient-Oriented Eczema Measure (POEM) in subjects aged 6 month to <2 years at screening. measure: Reduction of in Patient-Oriented Eczema Measure (POEM) ≥6 in subjects aged 2 to <12 years at screening. measure: Reduction of in Patient-Oriented Eczema Measure (POEM) ≥6 in subjects aged 6 month to <2 years at screening. measure: Percent change in Scoring Atopic Dermatitis (SCORAD) sleep loss in subjects aged 2 to <12 years at screening. measure: Percent change in Scoring Atopic Dermatitis (SCORAD) sleep loss in subjects aged 6 month to <2 years at screening. measure: Change in Child Worst Itch NRS (weekly average) for subjects aged 6 to <12 years at screening. measure: Change in Scratch Observer-Reported Outcome (ObsRO) (weekly average) in subjects aged 2 to <6 years at screening. measure: Change in Scratch Observer-Reported Outcome (ObsRO) (weekly average) in subjects aged 6 month to <2 years at screening. measure: Reduction in Children's Dermatology Life Quality Index (CDLQI) ≥6 for subjects aged 4 to <12 years at screening. measure: Number of treatment-emergent adverse events (AEs) per subject aged 2 to <12 years at screening. measure: Number of treatment-emergent adverse events (AEs) per subject aged 6 month to <2 years at screening. measure: Presence of treatment-emergent anti-drug antibodies (yes/no) in subjects aged 2 to <12 years at screening. measure: Presence of treatment-emergent anti-drug antibodies (yes/no) in subjects aged 6 month to <2 years at screening. measure: Rescue treatment use (yes/no) in subjects aged 2 to <12 years at screening. measure: Rescue treatment use (yes/no) in subjects aged 6 month to <2 years at screening. measure: Number of TCS free days in subjects aged 2 to <12 years at screening. measure: Number of TCS free days in subjects aged 6 month to <2 years at screening. measure: Investigator's Global Assessment for atopic dermatitis (IGA 0/1) score of 0 (clear) or 1 (almost clear) in subjects aged 2 to <12 years at screening. measure: Investigator's Global Assessment for atopic dermatitis (IGA 0/1) score of 0 (clear) or 1 (almost clear) in subjects aged 6 month to <2 years at screening. measure: Having at least 75% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 6 month to <2 years at screening. measure: Having at least 75% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 2 to <12 years at screening. measure: Having at least 90% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 6 month to <2 years at screening. measure: Having at least 90% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 2 to <12 years at screening. measure: Percent change in EASI in subjects aged 2 to <12 years at screening. measure: Percent change in EASI in subjects aged 6 month to <2 years at screening. measure: Percent change in Scoring Atopic Dermatitis (SCORAD) in subjects aged 2 to <12 years at screening. measure: Percent change in Scoring Atopic Dermatitis (SCORAD) in subjects aged 6 month to <2 years at screening. measure: Percent change in affected body surface area (BSA) in subjects aged 2 to <12 years at screening. measure: Percent change in affected body surface area (BSA) in subjects aged 6 month to <2 years at screening. measure: Percent change in Scoring Atopic Dermatitis (SCORAD) sleep loss in subjects aged 2 to <12 years at screening. measure: Percent change in Scoring Atopic Dermatitis (SCORAD) sleep loss in subjects aged 6 month to <2 years at screening. measure: Percent change in Children's Dermatology Life Quality Index (CDLQI) in subjects aged 4 to <12 years at screening. measure: Reduction in Children's Dermatology Life Quality Index (CDLQI) ≥6 for subjects aged 4 to <12 years at screening. measure: Reduction of in Patient-Oriented Eczema Measure (POEM) ≥6 in subjects aged 2 to <12 years at screening. measure: Reduction of in Patient-Oriented Eczema Measure (POEM) ≥6 in subjects aged 6 month to <2 years at screening. measure: Number of treatment-emergent adverse events (AEs) per subject aged 2 to <12 years at screening. measure: Number of treatment-emergent adverse events (AEs) per subject aged 6 month to <2 years at screening. measure: Presence of treatment-emergent anti-drug antibodies (yes/no) in subjects aged 2 to <12 years at screening. measure: Presence of treatment-emergent anti-drug antibodies (yes/no) in subjects aged 6 month to <2 years at screening. measure: Number of treatment-emergent adverse events (AEs) per subject aged 2 to <12 years at screening. measure: Number of treatment-emergent adverse events (AEs) per subject aged 6 month to <2 years at screening. measure: Investigator's Global Assessment for atopic dermatitis (IGA 0/1) score of 0 (clear) or 1 (almost clear) in subjects aged 2 to <12 years at screening. measure: Investigator's Global Assessment for atopic dermatitis (IGA 0/1) score of 0 (clear) or 1 (almost clear) in subjects aged 6 month to <2 years at screening. measure: Having at least 75% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 2 to <12 years at screening. measure: Having at least 75% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 6 month to <2 years at screening. measure: Having at least 90% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 2 to <12 years at screening. measure: Having at least 90% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 6 month to <2 years at screening. measure: Percent change in EASI in subjects aged 2 to <12 years at screening. measure: Percent change in EASI in subjects aged 6 month to <2 years at screening. measure: Percent change in Scoring Atopic Dermatitis (SCORAD) sleep loss in subjects aged 2 to <12 years at screening. measure: Percent change in Scoring Atopic Dermatitis (SCORAD) sleep loss in subjects aged 6 month to <2 years at screening. measure: Percent change in Children's Dermatology Life Quality Index (CDLQI) for subjects aged 4 to <12 years at screening. measure: Reduction in Children's Dermatology Life Quality Index (CDLQI) ≥ 6 for subjects aged 4 to <12 years at screening. measure: Investigator's Global Assessment for atopic dermatitis (IGA 0/1) score of 0 (clear) or 1 (almost clear) in subjects aged 2 to <12 years at screening. measure: Investigator's Global Assessment for atopic dermatitis (IGA 0/1) score of 0 (clear) or 1 (almost clear) in subjects aged 6 month to <2 years at screening. measure: Having at least 75% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 2 to <12 years at screening. measure: Having at least 75% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 6 month to <2 years at screening. measure: Having at least 90% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 2 to <12 years at screening. measure: Having at least 90% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 6 month to <2 years at screening. measure: Percent change in EASI in subjects aged 2 to <12 years at screening. measure: Percent change in EASI in subjects aged 6 month to <2 years at screening. measure: Percent change in Scoring Atopic Dermatitis (SCORAD) sleep loss in subjects aged 2 to <12 years at screening. measure: Percent change in Scoring Atopic Dermatitis (SCORAD) sleep loss in subjects aged 6 month to <2 years at screening. measure: Percent change in Children's Dermatology Life Quality Index (CDLQI) for subjects aged 4 to <12 years at screening. measure: Reduction in Children's Dermatology Life Quality Index (CDLQI) ≥ 6 for subjects aged 4 to <12 years at screening. measure: Investigator's Global Assessment for atopic dermatitis (IGA 0/1) score of 0 (clear) or 1 (almost clear) in subjects aged 2 to <12 years at screening. measure: Investigator's Global Assessment for atopic dermatitis (IGA 0/1) score of 0 (clear) or 1 (almost clear) in subjects aged 6 month to <2 years at screening. measure: Having at least 75% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 2 to <12 years at screening. measure: Having at least 75% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 6 month to <2 years at screening. measure: Having at least 90% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 2 to <12 years at screening. measure: Having at least 90% reduction in Eczema Area and Severity Index (EASI) score in subjects aged 6 month to <2 years at screening. measure: Percent change in EASI in subjects aged 2 to <12 years at screening. measure: Percent change in EASI in subjects aged 6 month to <2 years at screening. measure: Percent change in Scoring Atopic Dermatitis (SCORAD) sleep loss in subjects aged 2 to <12 years at screening. measure: Percent change in Scoring Atopic Dermatitis (SCORAD) sleep loss in subjects aged 6 month to <2 years at screening. measure: Percent change in Children's Dermatology Life Quality Index (CDLQI) for subjects aged 4 to <12 years at screening. measure: Reduction in Children's Dermatology Life Quality Index (CDLQI) ≥ 6 for subjects aged 4 to <12 years at screening. sex: ALL minimumAge: 6 Months maximumAge: 11 Years stdAges: CHILD hasResults: False