Tralokinumab improves skin microbial dysbiosis in atopic dermatitis

In patients with atopic dermatitis (AD), treatment with the IL-13 cytokine-targeting tralokinumab appears to directly or indirectly improves skin microbial dysbiosis, reports a new trial.

Researchers enrolled 802 patients (mean age 38.8 years, 59.1 percent men), of whom 84 provided skin swab samples for the microbiome analysis. Of the microbiome subgroup, 59 were randomly allocated to tralokinumab every other week, while 25 received placebo. Scores in the Eczema Area and Severity Index, Scoring Atopic Dermatitis, and Dermatology Life Quality Index were comparable between treatment arms.

Treatment with tralokinumab led to a more-than 20-fold reduction in Staphylococcus aureus abundance, dropping from 1,157 gene copies/cm² at baseline to 56 gene copies/cm² after 16 weeks (p<0.0001). Meanwhile, placebo participants saw a 2.1-fold drop in S. aureus gene copy number, which fell short of statistical significance.

Comparing both arms revealed a 10-fold reduction in S. aureus absolute abundance in lesional skin at 16 weeks in the tralokinumab group (p<0.0001).

In the tralokinumab group, the reduction in S. aureus abundance was accompanied by a relative increase in other microbial genera, but these remained in similar proportions with each other. No such change was reported for the placebo participants, in whom the relative abundance of major phyla remained stable across 16 weeks.

“In adult participants with moderate-to-severe AD, relative to placebo, tralokinumab treatment led to reduction of S. aureus abundance in lesional skin […] and increased Shannon diversity observed at the earliest timepoint assessed,” the researchers said. “Future research should address the dynamics of tralokinumab-induced modification of the skin microbiome and its relationship to improved short-term and long-term AD patient outcomes.”