Evaluation of FB-401 in Children, Adolescents and Adults (2 Years and Older) With Mild to Moderate Atopic Dermatitis

Inclusion Criteria: * Male or female, ≥ 2 years of age * Clinical diagnosis of atopic dermatitis as defined by Hanifin and Rajka criteria that has been present for ≥ 3 months before the screening visit * Investigator Global Assessment (IGA) score of 2 (mild) or 3 (moderate) at Screening and Baseline/Day 1 using the validated IGA scale for atopic dermatitis * EASI score ≥ 5 at the screening and the Baseline visit * 5% to 30% (inclusive) body surface area of atopic dermatitis involvement at the screening and the baseline visit Exclusion Criteria: * Previous treatment within 4 weeks prior to the baseline visit with any of the following: * Immunosuppressive or immunomodulating systemic drugs such as systemic (intravenous, oral, intra-articular or intramuscular) corticosteroids, azathioprine, methotrexate, cyclosporine * Phototherapy or photo chemotherapy for atopic dermatitis * Previous treatment within 1 week prior to the baseline visit with any of the following: * Topical corticosteroids (does not include inhaled, intranasal or ophthalmic) or topical calcineurin inhibitors * Topical phosphodiesterase type 4 (PDE4) inhibitor * Use of emollients other than provided for the study * Bleach baths * Within 8 weeks or 5 half-lives (if known), whichever is longer, prior to the baseline visit with Janus kinase inhibitors or other investigational drug * Within16 weeks or 5 half-lives, whichever is longer, prior to the baseline visit with dupilumab or other biologic agent to treat atopic dermatitis * Within 1 year prior to the baseline visit with any live bacterial therapy * Pregnant (or planning to become pregnant during the period of the study) or lactating females