A Study to Assess the Efficacy and Safety of RO7790121 in Participants With Moderate to Severe Atopic Dermatitis

Inclusion Criteria:

• AD diagnosis confirmed by a dermatologist according to the Hanifin/Rajka criteria atleast 1 year prior to screening

• Moderate to severe AD

• At least once daily use of an additive-free, bland emollient for at least 7 daysprior to the baseline visit and during the study

Exclusion Criteria:

• Evidence of other skin conditions that would interfere with the assessment of AD,including, but not limited to, for example cutaneous T-cell lymphoma, allergiccontact dermatitis

• IV, IM, IL, and oral corticosteroids (inhaled, ophthalmic drops, and nasalcorticosteroids are allowed) within 4 weeks of the baseline visit and during thestudy

• Topical treatment for AD including, but not limited to topical corticosteroids,topical calcineurin Inhibitors, topical PDE-4 inhibitors, , prescriptionmoisturizers or moisturizers containing additives such as ceramide, hyaluronic acid,urea or filaggrin within 7 days prior to the baseline visit and during the study

• Any active infection or other active skin diseases that required treatment withparenteral anti-infectives within 4 weeks or oral anti-infective treatment within 2weeks prior to baseline

• Acquired or congenital immunodeficiency

• Systemic therapies that are also used in the treatment of AD, including, but notlimited to methotrexate, cyclosporine, azathioprine, mycophenolate mofetil within 4weeks of the baseline visit and during the study