Laura W.J. van der Meulen, M. Bergmans, Salma Assil, Ismahaan Abdisalaam, Rianne Rijneveld, Erica S. Klaassen, Alexa J. Tibboel, Thorsten Brach, Bjorn L. Herpers, Johan Frieling, Benthe Freyee, Karin Platenkamp, Mariette E. van Poelgeest, Robert Rißmann, Martijn B. A. van Doorn, Tessa Niemeyer‐van der Kolk
Atopic dermatitis (AD) is a chronic immune-mediated inflammatory skin disease. An overgrowth of Staphylococcus aureus (S. aureus) and decreased microbial diversity is apparent in 70%-90% of AD patients. SA.100 is a recombinant endolysin targeting S. aureus that might be a novel treatment for patients with mild-to-moderate AD. To test safety, pharmacodynamics and efficacy of SA.100 a double-blind, randomized, vehicle-controlled trial in 53 subjects with mild-to-moderate AD was performed. Patients were randomized equally to topical SA.100 or vehicle with stratification for S. aureus positivity. SA.100 was safe and well tolerated. No reduction of S. aureus and no changes in microbiome features were seen after 2 weeks of treatment. Additionally, no statistically significant changes in clinical or patient-reported outcomes were observed compared to vehicle. In conclusion, topical SA.100 was safe and well tolerated in patients with mild-to-moderate AD, but our findings do not support short-term clinical use.