A Dose Finding Study to Investigate the Safety and Effectiveness of GSK1070806 in Adult Participants With Moderate to Severe Atopic Dermatitis

Inclusion Criteria: Adult participants 18 years to 75 years of age Participants with: AtD defined by the AAD Consensus Criteria. Diagnosis of AtD ≥1 year. An IGA score ≥3. AtD involvement of ≥10% body surface area (BSA). EASI score ≥16 Baseline pruritus numerical rating scale average score for maximum intensity of at least 3. Participants may have had exposure to 1 biologic therapy meeting at least 1 of the following conditions: Participants who stopped treatment due to non-response, partial response, loss of efficacy. Participants who stopped treatment due to intolerance or AEs. Participants who stopped treatment due to cost or loss of access. Participant with a recent history less than or equal to (≤6) months prior to the Screening visit) of inadequate response to a stable regimen of prescription topical medication. Participants for whom prescription topical medications are not tolerated. Contraceptive use by women should be consistent with local regulations regarding the methods of contraception for those participating in clinical study Exclusion Criteria: Chronic or acute infection requiring treatment with oral or IV antibiotics, antivirals, anti-protozoal, or antifungals within 4 weeks before the Screening visit or anytime between the Screening and Baseline visits. Superficial skin infections within 1 week before the Screening visit or active infections (including localized infections), or history of recurrent infections (excluding recurrent fungal infections of the nail bed) Known, pre-existing or suspected parasitic infection within 6 months before the Screening visit. Symptomatic herpes zoster within 3 months prior to screening Uncontrolled hypertension. Current or chronic history of liver disease or known hepatic or biliary abnormalities. Known or suspected history of immunosuppression, including history of invasive opportunistic infections despite infection resolution or unusually frequent, recurrent, or prolonged infections, per the Investigator's judgment. Lymphoma, leukemia, or any malignancy within the past 5 years except for basal cell or squamous epithelial carcinomas of the skin that have been resected with no evidence of metastatic disease for 3 years Breast cancer within the past 10 years. History or presence of significant medical illness including but not limited to cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrine, hematologic, neurological, or psychiatric disorders which in the opinion of the investigator would interfere with the study procedures and/or assessments. Previously treated with any oral Janus Kinase inhibitor (JAKi) or other kinase inhibitors, experimental or approved. Uncontrolled chronic disease that might require bursts of oral corticosteroids, e.g., co-morbid severe uncontrolled asthma. Presence of Hepatitis B surface antibody (HBsAg) or Hepatitis B core antibody (HBcAb) at screening or within 3 months prior to first dose of study intervention. Positive hepatitis C antibody test result at screening or within 3 months prior to starting study intervention. Positive hepatitis C RNA test result at screening or within 3 months prior to first dose of study intervention. Positive HIV antibody test. Evidence of active or latent TB as documented by medical history, examination, and TB testing with a positive QuantiFERON test at initial Screening visit. Pregnant or breastfeeding women, or women planning to become pregnant or breastfeed during the study.