biostudies-literatureWeiss ANNF Center for BiosustainabilityNovo Nordisk Fondene790https://www.ebi.ac.uk/biostudies/studies/S-EPMC9076020biostudies-literatureUnknown12(5)<h4>Background</h4>In patients with atopic dermatitis (AD), Staphylococcus aureus frequently colonizes lesions and is hypothesized to be linked to disease severity and progression. Treatments that reduce S. aureus colonization without significantly affecting the skin commensal microbiota are needed.<h4>Methods and findings</h4>In this study, we tested ATx201 (niclosamide), a small molecule, on its efficacy to reduce S. aureus and propensity to evolve resistance in vitro. Various cutaneous formulations were then tested in a superficial skin infection model. Finally, a Phase 2 randomized, double-blind and placebo-controlled trial was performed to investigate the impact of ATx201 OINTMENT 2% on S. aureus colonization and skin microbiome composition in patients with mild-to-severe AD (EudraCT:Clinical and translational medicineTopical niclosamide (ATx201) reduces Staphylococcus aureus colonization and increases Shannon diversity of the skin microbiome in atopic dermatitis patients in a randomized, double-blind, placebo-controlled Phase 2 trial.PMC9076020Microbial FoodsNNF10CC1016517Delavenne EWesth HZeitlinger MButty PStingl GM'Zali FBauer MPace JLundberg CVToft-Kehler RPriemel PSorensen NBangert CMatias CWeber MRades TNielsen HMQuint TJohansen HKNielsen HBWeiss ALi PMatzneller PMylonakis ESommer MKim WLagler HNussbaumer-Proll AEberl SHansen JUGuttman-Yassky EAnne Osterreicher ZSimon DJana BDos Santos TPGuardabassi LFriis CfalseTopical niclosamide (ATx201) reduces Staphylococcus aureus colonization and increases Shannon diversity of the skin microbiome in atopic dermatitis patients in a randomized, double-blind, placebo-controlled Phase 2 trial.<h4>Background</h4>In patients with atopic dermatitis (AD), Staphylococcus aureus frequently colonizes lesions and is hypothesized to be linked to disease severity and progression. Treatments that reduce S. aureus colonization without significantly affecting the skin commensal microbiota are needed.<h4>Methods and findings</h4>In this study, we tested ATx201 (niclosamide), a small molecule, on its efficacy to reduce S. aureus and propensity to evolve resistance in vitro. Various cutaneous formulations were then tested in a superficial skin infection model. Finally, a Phase 2 randomized, double-blind and placebo-controlled trial was performed to investigate the impact of ATx201 OINTMENT 2% on S. aureus colonization and skin microbiome composition in patients with mild-to-severe AD (EudraCT:2022-01-01T00:00:00Z2022 May2026-05-09T15:21:02.703Z2024-11-07T13:40:26.871ZS-EPMC90760203552290010.1002/ctm2.790