Clinical Effect, Safety and Tolerability of GSK1070806 in Atopic Dermatitis

Inclusion criteria: * Moderate to severe AtD (confirmed by a dermatologist) according to the Hannifin and Rajka criteria or Eichenfield revised criteria. * Onset of AtD symptoms occurring at least 6 months prior to Screening, with stable disease for at least 1 month prior to Screening. * Eczema Activity Severity Index greater than or equal to (\>=)16; Investigator Global Assessment score \>=3. * Group 1- Biologic Naïve: Topical First Line Treatment: Documented recent history (within 6 months before Screening) of: a) either an inadequate response (IR) to out-patient treatment with at least one topical treatment (intermittent topical corticosteroid, topical calcineurin inhibitor), topical inhibitors or Phosphodiesterase 4 inhibitor (Crisaborole); b) or that topical treatments were otherwise not recommended. * Group 2- Dupilumab-Inadequate Responder: Documented history of an IR to dupilumab: a) either following at least 16 weeks of treatment according to the Investigator's judgement; b) or intolerant to dupilumab owing to adverse events. Exclusion Criteria: * Other than AtD, the presence of a significant skin morbidity that will influence the Investigator's ability to assess the severity of the disease (e.g. psoriasis, confirmed or suspected cutaneous T-cell lymphoma, autoimmune bullous disease, fixed drug reaction and Stevens Johnson Syndrome). * Participants with any uncontrolled medical conditions, other than AtD, that in the opinion of the investigator puts the participan…