International consensus on methotrexate dosing for patients with atopic dermatitis: An eDelphi study.

BACKGROUND: Despite the widespread off-label use of methotrexate (MTX) for the treatment of atopic dermatitis (AD), there is limited high-quality evidence on dosing regimens and existing guidelines do not provide clear recommendations regarding dosing strategies. OBJECTIVE: The aim of this study was to achieve international consensus among AD experts to standardize the dosing regimen for MTX treatment in adults and children with AD. METHODS: An electronic Delphi (eDelphi) study was conducted from October 2021 to September 2022. Recruitment was conducted through dermatology societies and AD interest groups. Participation was open to dermatologists and dermatology residents experienced in treating AD patients with MTX. The study consisted of three online rounds. The first round was informed by a systematic review of relevant literature, and subsequent rounds were adjusted based on the results of the previous round. Participants voted on 19 proposals using a 9-point scale (1-3 disagree, 4-6 neither agree nor disagree, 7-9 agree). Consensus was achieved when at least 70% of participants agreed, and less than 15% disagreed. Proposals that did not reach consensus in the first three rounds were discussed in a consensus meeting, where consensus was defined as less than 30% disagreement. RESULTS: In total, 152 participants completed Round 1, 104 (68%) completed all survey rounds, and 43 (28%) joined the consensus meeting. Consensus was achieved on 7 proposals in Round 1, 4 in Round 2 and 6 in Round 3. The final 2 proposals reached consensus during the consensus meeting. Consensus topics include test dose, start dose, maximum dose, administration route, dosing schedule, management of stopping treatment, treatment duration and folic acid supplementation. CONCLUSIONS: This eDelphi study achieved consensus on 19 proposals related to MTX dosing for adults and children with AD. These results aim to guide prescribing decisions and encourage a standardized global approach to MTX use in AD.

Systemic Immunomodulatory Treatments for Atopic Dermatitis: Living Systematic Review and Network Meta-Analysis Update.

Importance: There are multiple approved systemic treatments for atopic dermatitis. Lebrikizumab is a newly licensed biologic medication that has been compared to placebo in clinical trials but not to other systemic treatments. Objective: To compare reported measures of efficacy and safety of lebrikizumab to other systemic treatments for atopic dermatitis in a living systematic review and network meta-analysis. Data Sources: The Cochrane Central Register of Controlled Trials, MEDLINE, Embase, the Latin American and Caribbean Health Science Information database, the Global Resource of Eczema Trials database, and trial registries were searched from inception through November 3, 2023. Study Selection: Randomized clinical trials evaluating 8 or more weeks of treatment with systemic immunomodulatory medications for moderate to severe atopic dermatitis. Titles, abstracts, and full texts were screened in duplicate. Data Extraction and Synthesis: Data were abstracted in duplicate and random-effects bayesian network meta-analyses were performed. Minimal important differences were used to define important differences between medications. Certainty of evidence was assessed using the GRADE approach (Grading of Recommendations Assessment, Development and Evaluation). The updated analysis was completed from December 13, 2023, to February 20, 2024. Main Outcome Measures: Efficacy outcomes were the Eczema Area and Severity Index (EASI), the Patient Oriented Eczema Measure (POEM) Dermatology Life Quality Index (DLQI), and Peak Pruritus Numeric Rating Scales (PP-NRS) and were compared using mean difference (MD) with 95% credible intervals (CrI). Safety outcomes were serious adverse events and withdrawal due to adverse events. Other outcomes included the proportion of participants with 50%, 75%, and 90% improvement in EASI (EASI-50, -75, -90) and the proportion with success on the Investigator Global Assessment compared using odds ratios with 95% CrI. Results: The study sample included 97 eligible trials, with a total of 24 679 patients. Lebrikizumab was associated with no important difference in change in EASI (MD, -2.0; 95% CrI, -4.5 to 0.3; moderate certainty), POEM (MD, -1.1; 95% CrI -2.5 to 0.2; moderate certainty), DLQI (MD, -0.2; 95% CrI -2.1 to 1.6; moderate certainty), or PP-NRS (MD, 0.1; 95% CrI -0.4, 0.6; high certainty) compared to dupilumab among adults with atopic dermatitis who were treated for up to 16 weeks. Dupilumab was associated with higher odds of efficacy in binary outcomes compared with lebrikizumab. The relative efficacy of other approved systemic medications was similar to that found by previous updates of this living study, with high-dose upadacitinib and abrocitinib demonstrating numerically highest relative efficacy. For safety outcomes, low event rates limited useful comparisons. Conclusions and Relevance: In this living systematic review and network meta-analysis, lebrikizumab was similarly effective to dupilumab for the short-term treatment of atopic dermatitis in adults. Clinicians and patients can use these comparative data to inform treatment decisions.

Clinical and humoral response after SARS-CoV-2 breakthrough infection in patients receiving immunosuppressant therapy.

BACKGROUND: Despite impaired humoral response in patients treated with immunosuppressants (ISPs), recent studies found similar severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) breakthrough infection compared to controls. One potential explanation is the rapid generation of humoral response on infection, but evidence is lacking. OBJECTIVES: We investigated the longitudinal dynamics of the SARS-CoV-2 antibody repertoire after SARS-CoV-2 delta and omicron breakthrough infection in patients with immune-mediated inflammatory diseases (IMIDs) receiving ISP therapy and controls. METHODS: As a prospective substudy of the national Target-to-B! (T2B!) consortium, we included IMID patients receiving ISPs therapy and controls who reported SARS-CoV-2 breakthrough infection between July 1, 2021, and April 1, 2022. To get an impression of the dynamics of the antibody repertoire, 3 antibody titers of wild-type RBD, wild-type S, and omicron RBD were measured at 4 time points after SARS-CoV-2 breakthrough infection. RESULTS: We included 302 IMID patients receiving ISPs and 178 controls. Antibody titers increased up to 28 days after breakthrough infection in both groups. However, in IMID patients receiving therapy with anti-CD20 and sphingosine-1 phosphate receptor modulators, antibody titers were considerably lower compared to controls. In the anti-TNF group, we observed slightly lower antibody titers in the early stages and a faster decline of antibodies after infection compared to controls. Breakthrough infections were mostly mild, and hospitalization was required in less than 1% of cases. CONCLUSIONS: Most ISPs do not influence the dynamics of the SARS-CoV-2 antibody repertoire and exhibit a rapid recall response with cross-reactive antibody clones toward new virus variants. However, in patients treated with anti-CD20 therapy or sphingosine-1 phosphate receptor modulators, the dynamics were greatly impaired, and to a lesser extent in those who received anti-TNF. Nevertheless, only a few severe breakthrough cases were reported.

Measuring Signs of Atopic Dermatitis in Clinical Practice: A HOME-CP Consensus Statement.

Importance: Outcome measurement is an essential component of value-based health care and can aid patient care, quality improvement, and clinical effectiveness evidence generation. The Harmonising Outcome Measures for Eczema Clinical Practice initiative aims to identify a list of validated, feasible, outcome measurement instruments recommended to measure atopic dermatitis (AD) in the clinical practice setting. The clinical practice set is a list of instruments that clinicians can pick and choose from to suit their needs in the context of clinical care. Objective: To recommend instruments to measure clinical signs of AD in clinical practice. Evidence Review: Following the predefined roadmap, a mixed methods design was implemented and incorporated systematic reviews and qualitative consensus methods. Previous systematic reviews identified few clinical signs instruments with sufficient validation for recommendation. An updated systematic review evaluating the validity of clinical signs instruments informed an international meeting to reach consensus on recommended instruments to measure AD clinical signs in clinical practice. Consensus was defined as less than 30% disagreement. An in-person consensus exercise was held in Montreal, Canada, on October 16, 2022. The 34 attendees included patient and patient advocate research partners, health care professionals, researchers, methodologists, and industry representatives. Findings: The updated systematic review found that the Eczema Area and Severity Index (EASI), Scoring Atopic Dermatitis, and objective Scoring Atopic Dermatitis were the only instruments that demonstrated sufficient performance in all assessed measurement properties. The modified EASI and Signs Global Assessment × Body Surface Area instruments were also recommended. The EASI, Validated Investigator Global Assessment, and Investigator's Global Assessment multiplied by or measured concurrently with a body surface area measure achieved consensus in criteria and were adopted. Conclusions and Relevance: This consensus statement by the Harmonising Outcome Measures for Eczema initiative suggests that when assessing and documenting clinical signs of AD, there are several valid and feasible instruments that can best fit a clinician's specific practice needs. These instruments should improve and standardize the documentation of signs severity, help determine the effect of treatment, facilitate the generation of clinical effectiveness evidence, and enhance the implementation of value-based health care.

Responsiveness of the condition-specific OVAMA questionnaire to measure symptoms and appearance in patients with vascular malformations.

BACKGROUND: Evidence-based guidelines for the treatment of vascular malformations are not readily available, possibly due to the diversity in methods used to evaluate treatment efficacy in clinical research, complicating the aggregation and comparison of study results. The OVAMA (Outcome Measures for VAscular Malformations) questionnaire was developed to uniformly measure symptoms and appearance, i.e., condition-specific core outcome domains, in patients with vascular malformations. However, the OVAMA questionnaire needs to be responsive to changes in these constructs in order to assess whether the disease status has altered since treatment. OBJECTIVES: To assess the responsiveness of the OVAMA questionnaire in patients with vascular malformations. METHODS: In a prospective longitudinal study, patients completed the OVAMA questionnaire at baseline and eight weeks follow-up since treatment or watchful waiting policy. Additionally, patients completed the Global rating of change (GRC) scales at follow-up. Responsiveness was evaluated following the criterion approach of testing predefined hypotheses about expected relationships between the OVAMA questionnaire and GRC scales, measuring the same constructs. The OVAMA questionnaire was considered responsive if ≥ 75% of the hypotheses were confirmed. RESULTS: Between July 2020 and September 2022, 89 patients were recruited in a vascular anomaly centre in the Netherlands, of which 63 patients completed the questionnaires at baseline and follow-up. In total, fifteen constructs of the OVAMA questionnaire were assessed for five hypotheses. Of these 75 hypotheses, 63 (84%) hypotheses were confirmed and thereby providing evidence that the OVAMA questionnaire is responsive to change. CONCLUSION: Our study found convincing evidence that the OVAMA questionnaire is responsive to changes in symptoms and appearance in patients with vascular malformations. In addition to determining a baseline of symptoms and appearance, the OVAMA questionnaire can now be used to evaluate the effect of treatment from the patient's perspective. The responsive OVAMA questionnaire allows for uniform evaluation and comparison of the effects of treatment on the condition-specific core outcome domains, tackling heterogeneity in outcome measurement and improving the clinical research of vascular malformations.

Suppressed IgG4 class switching in dupilumab- and TNF inhibitor-treated patients after mRNA vaccination.

BACKGROUND: The noninflammatory immunoglobulin G4 (IgG4) is linked to tolerance and is unique to humans. Although poorly understood, prolonged antigenic stimulation and IL-4-signaling along the T helper 2-axis may be instrumental in IgG4 class switching. Recently, repeated SARS-CoV-2 mRNA vaccination has been linked to IgG4 skewing. Although widely used immunosuppressive drugs have been shown to only moderately affect humoral responses to SARS-CoV-2 mRNA vaccination, the effect on IgG4 switching has not been investigated. METHODS: Here we study the impact of such immunosuppressive drugs, including the IL-4 receptor-blocking antibody dupilumab, on IgG4 skewing upon repeated SARS-CoV-2 mRNA vaccination. Receptor-binding domain (RBD) specific antibody responses were longitudinally measured in 600 individuals, including patients with immune-mediated inflammatory diseases treated with a TNF inhibitor (TNFi) and/or methotrexate (MTX), dupilumab, and healthy/untreated controls, after repeated mRNA vaccination. RESULTS: We observed a substantial increase in the proportion of RBD-specific IgG4 antibodies (median 21%) in healthy/untreated controls after third vaccination. This IgG4 skewing was profoundly reduced in dupilumab-treated patients (<1%). Unexpectedly, an equally strong suppression of IgG4 skewing was observed in TNFi-treated patients (<1%), whereas MTX caused a modest reduction (7%). RBD-specific total IgG levels were hardly affected by these immunosuppressive drugs. Minimal skewing was observed, when primary vaccination was adenoviral vector-based. CONCLUSIONS: Our results imply a critical role for IL-4/IL-13 as well as TNF in vivo IgG4 class switching. These novel findings advance our understanding of IgG4 class switch dynamics, and may benefit humoral tolerance induction strategies, treatment of IgG4 pathologies and mRNA vaccine optimization.

Protocol of a scoping review of outcome domains in dermatology.

INTRODUCTION: Core outcome sets (COSs) are agreed outcomes (domains (subdomains) and instruments) that should be measured as a minimum in clinical trials or practice in certain diseases or clinical fields. Worldwide, the number of COSs is increasing and there might be conceptual overlaps of domains (subdomains) and instruments within disciplines. The aim of this scoping review is to map and to classify all outcomes identified with COS projects relating to skin diseases. METHODS AND ANALYSIS: We will conduct a scoping review of outcomes of skin disease-related COS initiatives to identify all concepts and their definitions. We will search PubMed, Embase and Cochrane library. The search dates will be 1 January 2010 (the point at which Core Outcome Measures in Effectiveness Trials (COMET) was established) to 1 January 2024. We will also review the COMET database and C3 website to identify parts of COSs (domains and/or instruments) that are being developed and published. This review will be supplemented by querying relevant stakeholders from COS organisations, dermatology organisations and patient organisations for additional COSs that were developed. The resulting long lists of outcomes will then be mapped into conceptually similar concepts. ETHICS AND DISSEMINATION: This study was supported by departmental research funds from the Department of Dermatology at Northwestern University. An ethics committee review was waived since this protocol was done by staff researchers with no involvement of patient care. Conflicts of interests, if any, will be addressed by replacing participants with relevant conflicts or reassigning them. The results will be disseminated through publication in peer-reviewed journals, social media posts and promotion by COS organisations.

Comparing binary efficacy outcomes for systemic immunomodulatory treatments for atopic dermatitis in a living systematic review and network meta-analysis.

BACKGROUND: Systemic treatments for atopic dermatitis (AD) are evaluated primarily in placebo-controlled trials with binary efficacy outcomes. In a living systematic review and network meta-analysis (NMA), we previously analysed continuous efficacy measures. OBJECTIVES: To compare binary efficacy outcomes of systemic treatments for AD. METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, Latin American and Caribbean Health Science Information (LILACS) database, Global Resource for Eczema Trials (GREAT) database and trial registries up to 1 March 2023. We included randomized trials examining ≥ 8 weeks of treatment with systemic immunomodulatory medications for moderate-to-severe AD. We screened titles, abstracts and full texts and abstracted data independently, in duplicate. Outcomes included the proportion of patients achieving at least 50%, 75% and 90% improvements in Eczema Area and Severity Index (EASI 50, EASI 75 and EASI 90, respectively) and Investigator Global Assessment (IGA) success. We performed random-effects Bayesian NMAs to calculate odds ratios (OR) and 95% credible intervals (CrIs) between each intervention for each outcome. RESULTS: Eighty-three trials with 22 122 participants were included in the systematic review. In analyses limited to trials of 8-16 weeks' duration with predominantly adult populations, abrocitinib 200 mg daily (OR 1.5, 95% CrI 1.1-2.2) and upadacitinib 15 mg daily (OR 1.7, 95% CrI 0.9-3.3) and 30 mg daily (OR 2.5, 95% CrI 1.3-5.0) were associated with higher odds of achieving EASI 50 vs. dupilumab. Abrocitinib 100 mg daily (OR 0.7, 95% CrI 0.5-1.0), baricitinib 2 mg daily (OR 0.4, 95% CrI 0.3-0.5) and 4 mg daily (OR 0.5, 95% CrI 0.3-0.7), and tralokinumab (OR 0.4, 95% CrI 0.3-0.6) were associated with lower odds of achieving EASI 50 vs. dupilumab. Results were similar for EASI 75, EASI 90 and IGA success. CONCLUSIONS: Supporting results for continuous outcome measures, upadacitinib 30 mg daily and abrocitinib 200 mg daily are the most efficacious with regard to binary efficacy endpoints up to 16 weeks in adults with moderate-to-severe AD, followed by upadacitinib 15 mg daily, dupilumab and abrocitinib 100 mg daily. Dupilumab and both doses of upadacitinib and abrocitinib are more efficacious than baricitinib 4 and 2 mg daily and tralokinumab.

How to use the Harmonising Outcome Measures for Eczema Core Outcome Set for atopic dermatitis trials: a users' guide.

BACKGROUND: The Harmonising Outcome Measures for Eczema (HOME) initiative has agreed upon the Core Outcome Set (COS) for use in atopic dermatitis (AD) clinical trials, but additional guidance is needed to maximize its uptake. OBJECTIVES: To provide answers to some of the commonly asked questions about using the HOME COS; to provide data to help with the interpretation of trial results; and to support sample size calculations for future trials. METHODS AND RESULTS: We provide practical guidance on the use of the HOME COS for investigators planning clinical trials in patients with AD. It answers some of the common questions about using the HOME COS, how to access the outcome measurement instruments, what training/resources are needed to use them appropriately and clarifies when the COS is applicable. We also provide exemplar data to inform sample size calculations for eczema trials and encourage standardized data collection and reporting of the COS. CONCLUSIONS: By encouraging adoption of the COS and facilitating consistent reporting of outcome data, it is hoped that the results of eczema trials will be more comprehensive and readily combined in meta-analyses and that patient care will subsequently be improved.

The wide variety of methotrexate dosing regimens for the treatment of atopic dermatitis: a systematic review.

Background:Methotrexate is an off-label therapy for atopic dermatitis. A lack of consensus on dosing regimens poses a risk of underdosing and ineffective treatment or overdosing and increased risk of side effects. This systematic review summarizes the available evidence on dosing regimens.Materials and methods:A literature search was conducted, screening all randomized controlled trials (RCTs) and guidelines published up to 6 July 2023, in the MEDLINE, Embase, and Cochrane Library databases.Results:Five RCTs and 21 guidelines were included. RCTs compared methotrexate with other treatments rather than different methotrexate dosing regimens. The start and maintenance doses in RCTs varied between 7.5-15 mg/week and 14.5-25 mg/week, respectively. Despite varied dosing, all RCTs demonstrated efficacy in improving atopic dermatitis signs and symptoms. Guidelines exhibited substantial heterogeneity but predominantly proposed starting doses of 5-15 mg/week for adults and 10-15 mg/m2/week for children. Maintenance doses suggested were 7.5-25 mg/week for adults and 0.2-0.7 mg/kg/week for children. One guideline suggested a test dose and nearly half advised folic acid supplementation.Conclusion:This systematic review highlights the lack of methotrexate dosing guidelines for atopic dermatitis. It identifies commonly recommended and utilized dosing regimens, serving as a valuable resource for clinicians prescribing methotrexate off-label and providing input for an upcoming consensus study.

The Harmonising Outcome Measures for Eczema (HOME) implementation roadmap.

BACKGROUND: Core outcome sets (COS) are consensus-driven sets of minimum outcomes that should be measured and reported in all clinical trials. COS aim to reduce heterogeneity in outcome measurement and reporting, and selective outcome reporting. Implementing COS into clinical trials is challenging. Guidance to improve COS uptake in dermatology is lacking. OBJECTIVES: To develop a structured practical guide to COS implementation. METHODS: Members of the Harmonising Outcome Measurement for Eczema (HOME) executive committee developed an expert opinion-based roadmap founded on a combination of a review of the COS implementation literature, the Core Outcome Measures in Effectiveness Trials (COMET) initiative resources, input from HOME members and experience in COS development and clinical trials. RESULTS: The data review and input from HOME members was synthesized into themes, which guided roadmap development: (a) barriers and facilitators to COS uptake based on stakeholder awareness/engagement and COS features; and (b) key implementation science principles (assessment-driven, data-centred, priority-based and context-sensitive). The HOME implementation roadmap follows three stages. Firstly, the COS uptake scope and goals need to be defined. Secondly, during COS development, preparation for future implementation is supported by establishing the COS as a credible evidence-informed consensus by applying robust COS development methodology, engaging multiple stakeholders, fostering sustained and global engagement, emphasizing COS ease of use and universal applicability, and providing recommendations on COS use. Thirdly, incorporating completed COS into primary (trials) and secondary (reviews) research is an iterative process starting with mapping COS uptake and stakeholders' attitudes, followed by designing and carrying out targeted implementation projects. Main themes for implementation projects identified at HOME are stakeholder awareness/engagement; universal applicability for different populations; and improving ease-of-use by reducing administrative and study burden. Formal implementation frameworks can be used to identify implementation barriers/facilitators and to design implementation strategies. The effect of these strategies on uptake should be evaluated and implementation plans adjusted accordingly. CONCLUSIONS: COS can improve the quality and applicability of research and, so, clinical practice but can only succeed if used and reported consistently. The HOME implementation roadmap is an extension of the original HOME roadmap for COS development and provides a pragmatic framework to develop COS implementation strategies.

Consensus on the therapeutic management of atopic dermatitis ‒ Brazilian Society of Dermatology: an update on phototherapy and systemic therapy using e-Delphi technique.

This publication is an update of the "Consensus on the therapeutic management of atopic dermatitis - Brazilian Society of Dermatology" published in 2019, considering the novel, targeted-oriented systemic therapies for atopic dermatitis. The initial recommendations of the current consensus for systemic treatment of patients with atopic dermatitis were based on a recent review of scientific published data and a consensus was reached after voting. The Brazilian Society of Dermatology invited 31 experts from all regions of Brazil and 2 international experts on atopic dermatitis who fully contributed to the process. The methods included an e-Delphi study to avoid bias, a literature search and a final consensus meeting. The authors added novel approved drugs in Brazil and the indication for phototherapy and systemic therapy for AD. The therapeutical response to systemic treatment is hereby reported in a suitable form for clinical practice and is also part of this updated manuscript.

Primary SARS-CoV-2 infection in patients with immune-mediated inflammatory diseases: long-term humoral immune responses and effects on disease activity.

BACKGROUND: Patients with immune-mediated inflammatory diseases (IMIDs) on immunosuppressants (ISPs) may have impaired long-term humoral immune responses and increased disease activity after SARS-CoV-2 infection. We aimed to investigate long-term humoral immune responses against SARS-CoV-2 and increased disease activity after a primary SARS-CoV-2 infection in unvaccinated IMID patients on ISPs. METHODS: IMID patients on active treatment with ISPs and controls (i.e. IMID patients not on ISP and healthy controls) with a confirmed SARS-CoV-2 infection before first vaccination were included from an ongoing prospective cohort study (T2B! study). Clinical data on infections and increased disease activity were registered using electronic surveys and health records. A serum sample was collected before first vaccination to measure SARS-CoV-2 anti-receptor-binding domain (RBD) antibodies. RESULTS: In total, 193 IMID patients on ISP and 113 controls were included. Serum samples from 185 participants were available, with a median time of 173 days between infection and sample collection. The rate of seropositive IMID patients on ISPs was 78% compared to 100% in controls (p < 0.001). Seropositivity rates were lowest in patients on anti-CD20 (40.0%) and anti-tumor necrosis factor (TNF) agents (60.5%), as compared to other ISPs (p < 0.001 and p < 0.001, respectively). Increased disease activity after infection was reported by 68 of 260 patients (26.2%; 95% CI 21.2-31.8%), leading to ISP intensification in 6 out of these 68 patients (8.8%). CONCLUSION: IMID patients using ISPs showed reduced long-term humoral immune responses after primary SARS-CoV-2 infection, which was mainly attributed to treatment with anti-CD20 and anti-TNF agents. Increased disease activity after SARS-CoV-2 infection was reported commonly, but was mostly mild. TRIAL REGISTRATION: NL74974.018.20, Trial ID: NL8900. Registered on 9 September 2020.

The clinical relevance of dupilumab serum concentration in patients with atopic dermatitis: a two-center prospective cohort study.

BACKGROUND: Dupilumab is prescribed in one dosage across adult atopic dermatitis patients. Differences in drug exposure may explain variation in treatment response. OBJECTIVE: Investigating the clinical relevance of dupilumab serum concentration in atopic dermatitis in real-world practice. METHODS: In two centers (Netherlands, UK), adults treated with dupilumab for atopic dermatitis were evaluated for effectiveness and safety pretreatment and at 2, 12, 24, and 48 weeks; trough serum samples were analyzed for dupilumab concentration at corresponding time points. RESULTS: In 149 patients, median dupilumab levels during follow-up ranged from 57.4 to 72.4 µg/mL. Levels showed high inter-patient and low intra-patient variability. No correlation was found between levels and ΔEASI. At 2 weeks, levels of ≥64.1 µg/mL predict EASI ≤7 at 24 weeks (specificity:100%, sensitivity:60%; p = .022). At 12 weeks, ≤32.7 µg/mL predicts EASI >7 at 24 weeks (sensitivity:95%, specificity:26%; p = .011). Inverse correlations were found between baseline EASI and levels at 2, 12, and 24 weeks (r = -0.25 to 0.36; p ≤ .023). Low levels were particularly observed in patients with adverse events, treatment interval deviation, and discontinuation. CONCLUSION: At the on-label dosage, the measured range of dupilumab levels does not seem to yield differences in treatment effectiveness. However, disease activity does seem to influence dupilumab levels - higher baseline disease activity results in lower levels at follow-up.