The Beginning Assessment of Cutaneous Treatment Efficacy of Roseomonas in Atopic Dermatitis trial; BACTERiAD I/II study, an open-label phase I/II trial, first looked at the therapeutic use of R. mucosa in 10 adults aged 18 years or older. Three sucrose mixtures with increasing doses of live R. mucosa bacteria were topically applied to two body areas – the antecubital fossae and a body surface of their choice – twice per week for 2 weeks per dose. At 6 weeks, the patients stopped using the mixtures and followed a 4-week washout phase.
Treatment was found to reduce mean antecubital SCORAD (SCORing Atopic Dermatitis) scores by 59.8%. Reduction in pruritus was even more pronounced, with a mean decrease of 78.5%. Treating the hands did not improve disease severity, even in patients whose symptoms improved in other body areas. One explanation may be the increased exposure of the hands to topical antimicrobials and environmental exposures, the researchers noted.
With the success in the adult cohort, the researchers enrolled five children aged 7-17 years in the study. These patients were treated twice weekly for 16 weeks. The pediatric patients experienced a mean decrease of 70.3% in their SCORAD scores. The mean decrease in pruritis was 78.8%.
All adults who responded continued to report improved symptoms after the washout period. The pediatric patients are now being evaluated in a washout period.
Four patients did not respond; three of them had a family history of AD persisting into adulthood. “The association between these complex medical histories and the lack of clinical response suggests that differences in heritable host and/or microbial factors may impact treatment responses,” wrote Ian A. Myles, MD, and his colleagues.
“Overall, our findings suggest the safety of topical R. mucosa therapy and justify continuation of our ongoing trial to assess safety and activity in a pediatric cohort of patients with AD. These studies will additionally assess changes in host serum markers, skin metabolomics, and the skin microbiota by culture and genomic methods.”