# Tralokinumab treatment improves the skin microbiota by increasing the microbial diversity in adults with moderate-to-severe atopic dermatitis: Analysis of microbial diversity in ECZTRA 1, a randomized controlled trial

Lisa Beck, Thomas Bieber, Stephan Weidinger, Marie Tauber, Hidehisa Saeki, Alan Irvine, Lawrence Eichenfield, Thomas Werfel, Petra Arlert, Li Jiang, et al.

► To cite this version:

Lisa Beck, Thomas Bieber, Stephan Weidinger, Marie Tauber, Hidehisa Saeki, et al. Tralokinumab treatment improves the skin microbiota by increasing the microbial diversity in adults with moderate-to-severe atopic dermatitis: Analysis of microbial diversity in ECZTRA 1, a randomized controlled trial. Journal of The American Academy of Dermatology, 2023, 88 (4), pp.816-823. 10.1016/j.jaad.2022.11.047. hal-04946055

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# Tralokinumab treatment improves the skin microbiota by increasing the microbial diversity in adults with moderate-to-severe atopic dermatitis: Analysis of microbial diversity in ECZTRA 1, a randomized controlled trial

Lisa A. Beck, MD,ª Thomas Bieber, MD, PhD,ᵇ,c Stephan Weidinger, MD, PhD,ᵈ Marie Tauber, MD, PhD,ᶜ Hidehisa Saeki, MD, PhD,f Alan D. Irvine, MD, DSc,g,h Lawrence F. Eichenfield, MD, i Thomas Werfel, MD, l,k Petra Arlert, PhD, l Li Jiang, PhD, l Mads Røpke, PhD, l and Amy S. Paller, MDm

**Background:** Atopic dermatitis (AD) is characterized by microbial dysbiosis, immune dysregulation, and an impaired skin barrier. Microbial dysbiosis in AD involves a reduction in diversity primarily driven by an increased abundance of *Staphylococcus aureus*. Tralokinumab, an approved treatment for adults with moderate-to-severe AD, improves the skin barrier and immune abnormalities by specifically targeting the interleukin 13 cytokine, but its impact on the skin microbiome is unknown.

**Objective:** To investigate how tralokinumab affects the skin microbiome by examining the lesional skin of adults with moderate-to-severe AD from the phase 3 ECZTRA 1 trial (NCT03131648).

**Methods:** Microbiome profiling, *S aureus* abundance, and biomarker data were assessed in a subset of ECZTRA 1 participants (*S aureus* abundance at baseline and week 16; microbiome profiling at baseline, and week 8/16; and serum sampling before dose and week 4/8/16/28/52).

**Results:** Tralokinumab treatment led to increased microbial diversity, reduced *S aureus* abundance, and increased abundance of the commensal coagulase-negative Staphylococci.

**Limitations:** Limitations include a lack of *S aureus* abundance data at week 8, sampling site variation between participants, and possible influence from concomitant systemic antiinfectives.

From the Department of Dermatology, Medicine and Pathology, University of Rochester Medical Center, Rochester, New Yorkª; Department of Dermatology and Allergy, University Hospital, Bonn, Germanyᵇ; Christine Kühne-Center for Allergy Research and Education, Davos, Switzerlandᶜ; Department of Dermatology and Allergy, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germanyᵈ; Dermatology and Allergology Department, Toulouse University Hospital and Inserm UMR1291 - CNRS UMR5051, Toulouse, Franceᵉ; Department of Dermatology, Nippon Medical School, Tokyo, Japanf; Clinical Medicine, Trinity College Dublin, Irelandg; Department of Dermatology, Children's Health Ireland, Dublin, Irelandh; Departments of Dermatology and Pediatrics, University of California San Diego School of Medicine, La Jolla, Californiai; Department of Dermatology and Allergy, j and Cluster of Excellence RESIST (EXC 2155), k Hannover Medical School, Hannover, Germany; LEO Pharma A/S, Ballerup, Denmarkk; Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinoism

Funding sources: ECZTRA 1 and this study were funded by LEO Pharma A/S. Medical writing support was funded by LEO Pharma A/S, according to Good Publication Practice guidelines

(https://www.ismpp.org/gpp3). The authors received no hono-
raria related to the development of this publication.

Presented at American Academy of Dermatology (AAD) Virtual Meeting Experience (VMX) 2021, Bieber T, et al. Neutralising interleukin-13 increases skin microbial diversity: results from ECZTRA 1, a phase 3, randomised, double-blind, placebo-controlled trial with tralokinumab in adult patients with atopic dermatitis. E-poster abstract #28170. April 23–25, 2021.

IRB approval status: The trials were approved by the local institutional review board or ethics committee of each participating institution.

Accepted for publication November 20, 2022.

Correspondence and reprint requests to: Lisa A. Beck, MD, Department of Dermatology, Medicine and Pathology, University of Rochester Medical Center, 40 Celebration Drive, Rochester, NY 14642. E-mail: Lisa_Beck@URMC.Rochester.edu.

Published online December 5, 2022.
0190-9622

© 2022 by the American Academy of Dermatology, Inc. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

https://doi.org/10.1016/j.jaad.2022.11.047
**Conclusion:** Our findings indicate specific targeting of the interleukin 13 cytokine with tralokinumab can directly and/or indirectly improve microbial dysbiosis seen in AD skin. (J Am Acad Dermatol 2023;88:816-23.)

**Key words:** atopic dermatitis; coagulase-negative Staphylococci (CoNS); ECZTRA 1; interleukin (IL)-13; microbiome; Shannon diversity; skin; *Staphylococcus aureus*; tralokinumab.

## INTRODUCTION

Atopic dermatitis (AD) is a chronic skin disease characterized by microbial dysbiosis, immune dysregulation, and an impaired skin barrier.¹ Affected individuals experience pain, itch, sleep loss, and reduced quality of life.²,³ Clinical manifestations include skin lesions, dryness, scaling, erythema, and excoriations.¹ Studies have pointed to a lack of microbial diversity and increased bacterial load with pathogenic strains, such as *Staphylococcus aureus* on AD skin.⁵⁻⁹ Individuals with AD are colonized with high levels of *S aureus* in both lesional and nonlesional skin at approximately 90%, whereas only 10% of healthy individuals harbor *S aureus*.¹⁰⁻¹³

Skin barrier abnormalities associated with AD facilitate *S aureus* binding and colonization.¹⁴,¹⁵ Skin homeostasis is enhanced by colonization of commensal bacteria that protect the host from pathogenic bacteria and their virulence factors.¹⁶⁻¹⁸ *S aureus* expresses an array of these virulence factors that further disrupt the skin barrier and promote inflammation.¹⁹,²⁰ Skin commensals can control *S aureus*-induced skin barrier damage and inflammation via the production of autoinducing peptides, which are quorum sensing molecules that inhibit one of the major *S aureus* virulence factors, the accessory gene regulator system.²¹ Recent studies have also indicated that commensal bacteria can enhance barrier restoration via signaling through the aryl hydrocarbon receptor in murine keratinocytes.²²

Immune-commensal crosstalk regulates *S aureus* skin colonization and is disrupted in AD.²³,²⁴ Dysregulation of the skin microbiome in acute flares of AD is believed to be influenced by skin barrier disruption, type 2 innate lymphoid cells, and T helper type 2 (type 2)-driven inflammation, in which the interleukin (IL) 13 cytokine plays a major role.²⁵ Excess of type 2 cytokines, such as IL-13, reduces skin

## CAPSULE SUMMARY

* Although earlier studies targeting both interleukin 4 and interleukin 13 signaling have shown normalization of the microbiome in atopic dermatitis skin, the present study demonstrates that specifically targeting interleukin 13 alone can result in similar improvements.

* Dermatologists may consider tralokinumab treatment to improve microbial diversity and reduce *Staphylococcus aureus* abundance on atopic dermatitis skin.

production of antimicrobial peptides (AMPs), facilitating *S aureus* infections in AD.²⁵ Type 2 polarization strongly associates with *S aureus* skin colonization in AD.⁹,²⁵ Sensing of commensal bacteria via pattern recognition receptors activates innate immunity, leading to an increase in regulatory and antiinflammatory pathways, which may attenuate skin inflammation.²⁶ Coagulase-negative Staphylococci (CoNS) also interact with the immune system by producing AMPs, which kill *S aureus* with high specificity

and synergize with human AMP IL-37.²³

Investigating the effect of biologics on the relationship between *S aureus* and the commensal skin microbiome is key in understanding how these biologics can improve this imbalance on AD skin. Recent findings suggest decreasing type 2 inflammation may influence the skin microbiota of individuals with AD.¹ For example, inhibition of IL-4 and IL-13 signaling, achieved with dupilumab treatment, reduced *S aureus* abundance on both lesional and nonlesional skin and increased microbial diversity as early as 4 weeks relative to placebo in adults with moderate-to-severe AD.²⁷,²⁸ Tralokinumab is a fully human, high-affinity monoclonal antibody that specifically neutralizes IL-13 and exhibited a favorable efficacy and safety profile for the treatment of adults with moderate-to-severe AD in 3 phase 3 trials.²⁹,³⁰ In this study, we examined the impact of tralokinumab treatment on microbial diversity in the lesional skin of adults with moderate-to-severe AD from the phase 3 ECZTRA 1 trial (NCT03131648).

## METHODS

### Study design and participant population

The ECZTRA 1 trial has been previously described.³⁰ The trials was sponsored by LEO Pharma and conducted in accordance with the ethical principles derived from the Declaration of
Abbreviations used:

ASV: Amplicon sequence variant

AD: Atopic dermatitis

AMP: Antimicrobial peptides

CCL: Chemokine ligand

CoNS: Coagulase-negative staphylococci

EASI: Eczema Area and Severity Index

IgE: immunoglobulin E

IL: interleukin

Q2W: Once every 2 weeks

TARC: thymus and activation-regulated chemokine

Helsinki and Good Clinical Practice guidelines and were approved by the local institutional review board or ethics committee of each institution. All patients provided written informed consent. Patients were enrolled from May 30, 2017, to March 5, 2018, in ECZTRA 1. ECZTRA 1 was a 52-week, randomized, double-blind, placebo-controlled, monotherapy, phase 3 trial in which adults with moderate-to-severe AD were randomized 3:1 to subcutaneous tralokinumab 300 mg or placebo once every 2 weeks (Q2W) for weeks 0 to 16, following an initial loading dose (tralokinumab 600 mg or placebo). For the subsequent maintenance treatment period (weeks 16-52), participants randomized to tralokinumab in the first 16 weeks who met the response criteria at week 16 (Investigator's Global Assessment scale 0/1 and/or Eczema Area and Severity Index [EASI]-75) were rerandomized in a 2:2:1 ratio to a maintenance regimen of tralokinumab 300 mg Q2W, tralokinumab 300 mg once every 4 weeks, or placebo. Participants not meeting response criteria at week 16 were transferred to open label tralokinumab 300 mg Q2W with optional topical corticosteroids. Participants who received rescue treatment during the initial treatment period were considered as nonresponders but continued to receive tralokinumab if rescue consisted of topical corticosteroids.

Certain concomitant medications related to AD treatment were permitted from screening through safety follow-up, including stable doses of an additive-free bland emollient twice-daily for at least 14 days prior to baseline and throughout the trial. Other permitted concomitant medications included oral antibiotics, antiviral, or antifungal therapy for skin infections as appropriate or oral antihistamines. Patients with systemic or serious skin infection within 4 weeks prior to randomization requiring treatment with antibiotics were excluded from the trial. Details regarding the ECZTRA 1 trial, such as randomization and the random allocation sequence, trial outcomes, and other trial findings have been previously described.³⁰ Participants provided

written consent for sample collection for the exploratory analyses in this study.

## Skin assessment and bacterial collection

Bacteria were collected from lesional areas (5 × 10 cm) of moderate-to-severe AD skin from the upper limb, lower limb, and/or trunk using 4N6FLOQSwabs. Subjects did not shower, bathe, or otherwise wash the lesion where the swab was to be taken from within 12 hours of sample collection. Dry swabs were rubbed with a rolling motion across the whole skin area for about 1 minute. Although there was no standardization of collection sites, swabs were applied at the same anatomic site at each time point throughout the study (for an individual subject) and were applied to the same lesions. The same skin area was sampled throughout the trial, even if any lesions in the area had resolved. After collection, the swabs were sealed in a dry pouch after sampling and shipped to a central laboratory (Eurofins Genomics A/S) for DNA and RNA extraction and analysis.

## Bacterial identification and quantification

*S. aureus* abundance was assessed at baseline and week 16, and microbiome profiling was performed at baseline, week 8, and week 16. Bacterial abundance was assessed using quantitative polymerase chain reaction of the *femA* gene (*S. aureus*) and 16S ribosomal RNA (bacteria overall) using the TaqMan Microbe Detection Assay Ba04230906_s1 and TaqMan Gene Expression Assay Ba04230899_s1, respectively (Thermo Fisher Scientific). Relative microbial abundance and Shannon diversity were assessed based on complementary DNA sequencing of 16S ribosomal RNA V3-V4 regions. Microbial diversity results are presented as Shannon diversity index (a quantitative measure of the number of bacterial species and the abundance of species present on the skin).

## Serum biomarker analysis

Serum samples were collected from 299 participants (233 on tralokinumab and 76 on placebo) at predose and week 4, 8, 16, 28, and 52. Serum biomarkers were measured as follows: IL-13 and IL-22 by Singulex Erenna Array; chemokine ligand (CCL)-17 and thymus and activation-regulated chemokine (TARC) by ELISA. Nonparametric Spearman correlation was used to determine the relationship between *S. aureus* abundance and serum biomarker levels. Serum total immunoglobulin E (IgE) and absolute eosinophil counts were analyzed as part of the standard clinical chemistry and hematology
<table><caption>**Table I.** Baseline demographics and clinical characteristics for randomized participants in parent study (ECZTRA 1) and in the skin swab subgroup</caption><thead><tr><th rowspan="2">Characteristic</th><th rowspan="2">All randomized (N = 802)</th><th colspan="2">Skin swab (microbiome) subgroup (N = 84)</th></tr><tr><th>Tralokinumab Q2W (n = 59)</th><th>Placebo (n = 25)</th></tr></thead><tbody><tr><td>Age (y), mean (SD)</td><td>38.8 (14.1)</td><td>39.9 (13.8)</td><td>36.8 (13.1)</td></tr><tr><td>Sex, n (%)</td><td></td><td></td><td></td></tr><tr><td>Male</td><td>474 (59.1)</td><td>37 (62.7)</td><td>16 (64.0)</td></tr><tr><td>Female</td><td>328 (40.9)</td><td>22 (37.3)</td><td>9 (36.0)</td></tr><tr><td>Race, n (%)</td><td></td><td></td><td></td></tr><tr><td>White</td><td>564 (70.3)</td><td>48 (81.4)</td><td>22 (88.0)</td></tr><tr><td>Black</td><td>59 (7.4)</td><td>2 (3.4)</td><td>1 (4.0)</td></tr><tr><td>Asian</td><td>160 (20.0)</td><td>8 (13.6)</td><td>2 (8.0)</td></tr><tr><td>IGA severity, n (%)</td><td></td><td></td><td></td></tr><tr><td>Moderate disease</td><td>391 (48.8)</td><td>23 (39.0)</td><td>14 (56.0)</td></tr><tr><td>Severe disease</td><td>407 (50.7)</td><td>36 (61.0)</td><td>11 (44.0)</td></tr><tr><td>EASI, mean (SD), n</td><td>32.4 (13.8), 798</td><td>35.6 (14.7), 59</td><td>32.8 (13.1), 25</td></tr><tr><td>SCORAD, mean (SD), n</td><td>70.6 (12.9), 798</td><td>74.2 (13.1), 59</td><td>72.1 (10.5), 25</td></tr><tr><td>DLQI, mean (SD), n</td><td>16.9 (7.0), 785</td><td>17.7 (6.6), 57</td><td>18.3 (6.6), 25</td></tr><tr><td>Worst daily pruritus NRS (weekly average), mean (SD), n</td><td>7.7 (1.4), 793</td><td>8.1 (1.4), 59</td><td>8.1 (1.2), 25</td></tr></tbody></table>

DLQI, Dermatology Life Quality Index; EASI, Eczema Area and Severity Index; IGA, Investigator's Global Assessment scale; NRS, Pruritus Numerical Rating Scale; SCORAD, Scoring Atopic Dermatitis; SD, standard deviation.

panel at the central laboratory using Roche instruments.

## RESULTS

### Baseline demographics and clinical characteristics

Of 802 randomized participants, *S aureus* abundance data was taken from 780 participants, and microbiome abundance and profiling were taken from 84 participants (59 on tralokinumab and 25 on placebo). Baseline demographics and clinical characteristics for all randomized participants and the microbiome subgroup are summarized in Table I. EASI, Scoring Atopic Dermatitis, and Dermatology Life Quality Index were similar between the tralokinumab and placebo groups at baseline.

### Bacterial identification and quantification

A total of 30,276 amplicon sequence variants (ASVs) were identified from 205 samples. The 205 samples were derived from the 84 participants who contributed to the microbiome swab collection at different time points. After taxonomic assignment of ASVs and filtering for ASVs found in more than one sample, a total of 9,130 ASVs were used for analysis representing 21 phyla, 468 genera and 791 species.

### S aureus abundance

The abundance of *S aureus* was reduced 20.7-fold, from 1157 to 56 gene copies/cm² (median values), during 16 weeks of treatment with

tralokinumab Q2W (*P* <.0001) (Fig 1). In placebo-treated subjects a 2.1-fold nonstatistically significant reduction in the *S aureus* gene copy number was observed (471 to 352 gene copies/cm²) (Fig 1).

When comparing the treatment effect in the tralokinumab and placebo-treated groups a 10-fold reduction from baseline in *S aureus* absolute abundance was seen for lesional skin at week 16 (ratio = 0.09; *P* <.0001) (Fig 1). Participants who used systemic antiinfectives between baseline and week 16, in line with permitted concomitant medications, were included (19.3% of placebo group, 19.5% of tralokinumab group); the exclusion of these patients did not affect *S aureus* abundance results (data not shown). The use of rescue therapy also did not impact the results (Supplementary Fig S1, available via Mendeley at https://doi.org/10.17632/vnfbmxpx22.1).

Treatment with tralokinumab led to reduced *S aureus* abundance in lesional skin relative to placebo at week 16 regardless of EASI-75 response; (N = 780) (Supplementary Fig S2, available via Mendeley at https://doi.org/10.17632/vnfbmxpx22.1), although the magnitude of difference between tralokinumab- and placebo-treated participants was larger in EASI-75 responders versus nonresponders. This suggests that treatment with tralokinumab contributes to the reduction in *S aureus* abundance after 16 weeks, rather than *S aureus* reductions occurring because of skin improvement alone. *S aureus* abundance moderately correlated with EASI at baseline and
<figure><img src="image_3.png" /><figcaption>**Fig 1.** Treatment with tralokinumab led to a greater reduction in *S aureus* absolute abundance in lesional skin relative to placebo at week 16 (N = 780). Statistical differences were analyzed using the unpaired *t* test.</figcaption></figure>

week 16, and a reduction in *S aureus* abundance was observed at week 16 compared with baseline (Supplementary Fig S3, available via Mendeley at https://doi.org/10.17632/vnfbmxpx22.1).

At baseline, *S aureus* abundance was moderately correlated with IL-13, IL-22, and CCL17/TARC levels on a nonparametric Spearman correlation (Supplementary Fig S4, available via Mendeley at https://doi.org/10.17632/vnfbmxpx22.1). *S aureus* abundance at baseline was also moderately correlated with IgE and absolute eosinophil count (Supplementary Fig S5, available via Mendeley at https://doi.org/10.17632/vnfbmxpx22.1).

## Microbial diversity

Relative abundance of major phyla and genera remained stable in lesional skin for participants receiving placebo, whereas the relative abundance of the genus *Staphylococcus* was reduced from baseline for the tralokinumab treatment group at both week 8 and 16 (38.9% reduced at week 8, 47.5% reduced at week 16) (Fig 2, A). In the tralokinumab treatment group, genera other than *Staphylococcus* increased in proportion overall in week 8 and week 16 but maintained similar proportions relative to each other.

At the species level, the overall decrease in the relative abundance of the genus *Staphylococcus* was primarily because of decreased relative abundance of *S aureus*, from comprising almost 32% of all bacteria at baseline to less than 8% of all bacteria at week 16 (Fig 2, B). Relative abundance also decreased for *S argenteus*, a pathogenic hemolysin-producing species associated with *S aureus*, from 5% of the genus *Staphylococcus* at baseline to 2% at

week 16 (Supplementary Fig S6, available via Mendeley at https://doi.org/10.17632/vnfbmxpx22.1). In contrast, the relative abundance of commensal CoNS, such as the ubiquitous skin colonizer *S epidermidis* and *S capitis*, were increased.

The tralokinumab group showed a significant increase in microbial diversity as assessed by Shannon diversity (a measure of the number and abundance of bacterial species) over time relative to the placebo group at week 8 and week 16 (Fig 3).

## DISCUSSION

ECZTRA 1 was a large, multinational phase 3 study that demonstrated the effectiveness and safety of tralokinumab monotherapy for moderate-to-severe AD. In adult participants with moderate-to-severe AD, relative to placebo, tralokinumab treatment led to reduction of *S aureus* abundance in lesional skin observed at the earliest time point assessed (week 16), increased Shannon diversity observed at the earliest time point assessed (week 8), and increased abundance of CoNS Staphylococci at week 8. Although *S aureus* abundance data were not collected for week 8, the proportion of *S aureus* relative to other microbial species was decreased at both week 8 and week 16.

Among those patients achieving an EASI-75 response, tralokinumab treatment induced a stronger reduction in *S aureus* abundance compared to placebo-treated subjects achieving EASI-75. This finding suggests that IL-13 inhibition by tralokinumab leads to a reduction of *S aureus* abundance and that the reduced colonization is not only the result of clinical disease improvement. A possible explanation is that neutralizing IL-13 may enable a more effective innate immune response by both keratinocytes and hematopoietic cells and potentially reduce *S aureus* adhesion to corneocytes, which warrants further investigation. Interestingly, *S aureus* abundance at baseline correlated moderately with circulating levels of IL-13, IL-22, CCL17/TARC, total IgE, and absolute eosinophil counts.

Limitations of the study include possible influence from concomitant systemic antiinfectives and/or additive-free emollient use on the microbiome. Although such use close to sample collection may influence results, systemic antiinfective use was equivalent in the tralokinumab- and placebo-treated arms and excluding these patients did not change *S aureus* abundance results. Likewise, emollient was used in both placebo and active arms and is therefore unlikely to account for the differences in treatment groups. Other limitations include variation between patients in sampling site, no *S aureus* abundance data collected at week 8 or earlier time
<figure><img src="image_4.png" /><figcaption>**Fig 2.** Microbial diversity in placebo and tralokinumab-treated participants. **A**, Relative abundance of the most dominant phyla and genera over time in lesional skin (N = 84; tralokinumab N = 59, placebo N = 25) and **B** relative abundance by species within the *Staphylococcus* genus (N = 84; tralokinumab N = 59, placebo N = 25).</figcaption></figure>

points, lack of metagenome and transcriptome data on the metabolic status of collected bacteria, no measurement of *S. aureus* virulence factor production, no quantification of epidermal barrier genes or antimicrobial peptide production, and limited biomarker data sets. Additionally, the human skin microbiome can vary by geographic region,³¹ and this study assessed the effect of placebo versus tralokinumab in some of the ECZTRA 1 study sites (US, France, Germany, Japan, and Spain).

Although the relationship between host inflammation and microbial dysbiosis has yet to be fully elucidated,¹ our findings support that specifically neutralizing the IL-13 cytokine contributes to improvements in microbial dysbiosis, with a decrease in *S. aureus* abundance and an increase in microbial diversity. Considering the influence of the relationship between the commensal skin microbiome and

*S. aureus* colonization on skin homeostasis, investigating both in the same samples allows for a comprehensive overview of the effect of tralokinumab on microbial dysbiosis in AD skin. Colonization with *S. aureus* is thought to contribute to epidermal barrier defects and release of inflammatory mediators, including type 2 alarmins.³² This study suggests that a reduction in *S. aureus* abundance because of tralokinumab treatment may allow for an increase in skin commensals, which are important for skin homeostasis by virtue of their regulatory and anti-inflammatory effects.¹⁶⁻¹⁸

The results for this study are similar to those observed with dupilumab.²⁷,²⁸ However, the similarity between the results for dupilumab, which targets both IL-13 and IL-4 signaling, and tralokinumab, which specifically targets IL-13, suggests that IL-13 may be the key driver of the altered AD skin
<figure><img src="image_5.png" /><figcaption>**Fig 3.** Treatment with tralokinumab led to increased Shannon diversity (N = 84; tralokinumab N = 59, placebo N = 25). Statistical differences between the tralokinumab treatment group and placebo group at baseline, week 8, and week 16 were analyzed using Tukey range test.</figcaption></figure>

microbiome, and that targeting only IL-13 is enough to change the microbial dysbiosis in AD skin. Because alterations in the skin microbiome in patients with AD have been well-characterized, improvement in the skin microbiome composition continues to be acknowledged as a potential therapeutic approach for AD.¹,³³,³⁴ Further research should address the dynamics of tralokinumab-induced modification of the skin microbiome and its relationship to improved short-term and long-term patient with AD outcomes.

The authors wish to thank the study participants, site PIs, and coordinators. Medical writing support, including assisting authors with the development of the manuscript drafts and incorporation of comments, was provided by Meredith Whitaker, PhD, and Krista Mills of Alphabet Health (New York, NY), supported by LEO Pharma A/S, according to Good Publication Practice guidelines (https://www.ismpp.org/gpp3).

### Conflict of interest

Dr Beck has been a consultant for Allakos, Arena Pharmaceuticals, DermTech, Evelo Biosciences, Galderma, Incyte, Janssen, LEO Pharma, Merck, Numab Therapeutics, Pfizer, Rapt Therapeutics, Regeneron, Ribon Therapeutics, Sanofi/Genzyme, Sanofi-Aventis, Stealth BioTherapeutics, Trevi Therapeutics, Union Therapeutics and Xencor; DMC member for Novartis; and investigator for AbbVie, Astra-Zeneca, DermTech, Kiniksa, Pfizer, Regeneron, and Ribon Therapeutics. Dr Bieber has been a speaker, and/or consultant, and/or investigator for AbbVie, Allmiral, AnaptysBio, Arena, Asana Biosciences, ASLAN pharma, Bayer Health, BioVerSys, Böhringer-Ingelheim, Bristol-Myers Squibb, Connect Pharma, Dermavant, Domain Therapeutics, Galderma, Glenmark, GSK, Incyte, Innovaderm, IQVIA, Janssen, Kirin, Kymab, LEO, LG Chem, Eli Lilly, L'Oréal, MSD, Novartis, Numab, OM-Pharma, Pfizer, Pierre Fabre, Q32bio, RAPT, Sanofi/

Regeneron, and UCB. He is founder and chairman of the board of the non-profit biotech "Davos Biosciences." Dr Weidinger received institutional research grants from La Roche Posay, LEO Pharma, and Sanofi Deutschland GmbH, and lecture and/or consultancy fees from AbbVie, Almirall, Eli Lilly, Kymab, LEO Pharma, Pfizer, Regeneron, and Sanofi-Genzyme. He is involved in performing clinical trials with many pharmaceutical industries that manufacture drugs used for the treatment of psoriasis and atopic dermatitis. Dr Tauber is an investigator for AbbVie, Boehringer Ingelheim, Eli Lilly, Galderma, LEO Pharma, Pierre Fabre, and Sanofi-Regeneron; a consultant or advisory board member for AbbVie, Eli Lilly, MEDAC, and Sanofi-Regeneron. Dr Saeki has received lecture fees from Kyorin, Kyowa Kirin, LEO Pharma, Maruho, Mitsubishi Tanabe, Sanofi, Taiho, and Tokiwa; and scholarship donations from Esai, Maruho, Mitsubishi Tanabe, and Torii. Dr Irvine reports personal fees (Speaker fees and Consulting fees) from AbbVie, Arena, Dermavant, Eli Lilly, LEO Pharma, Pfizer, Regeneron, and Sanofi. Dr Eichenfield has been a scientific adviser and/or clinical study investigator for AbbVie, Almirall, Asana, Aslan, Dermavant, Eli Lilly, Forte, Galderma, Glenmark, Incyte, LEO Pharma, Novartis, Ortho Dermatologics, Pfizer Inc., Regeneron, and Sanofi-Genzyme. Dr Werfel received lecture and/or consultancy fees from AbbVie, Almirall, Galderma, Eli Lilly, Janssen/JNJ, LEO Pharma, Novartis, Pfizer, and Regeneron/Sanofi. Drs Arlert, Jiang, and Røpke are employees of LEO Pharma. Dr Paller has been an investigator for AbbVie, Incyte, Eli Lilly, and Regeneron; Data Safety Monitoring Board for AbbVie, Bausch and Galderma; and consultant for AbbVie, Almirall, Anaptysbio, Arena, BiomX, Boehringer Ingelheim, Eli Lilly, Forte, LEO Pharma, Novartis, Pfizer, Regeneron, and Sanofi-Genzyme.

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