Serum Dupilumab levels fail to reveal treatment response in Atopic Dermatitis at 16 weeks

A new clinical study found that serum dupilumab levels do not affect treatment response and adverse effects during the first year of treatment at 16 weeks of treatment in Atopic Dermatitis (AD). The study results were published in the journal JAMA Network. 

Dupilumab is a human monoclonal antibody that targets the interleukin (IL)-4 receptor subunit-α (IL-4Rα) and inhibits the entire T2 pathway. The dose of dupilumab for adult patients with atopic dermatitis (AD) is 300 mg every other week. But there is uncertainty if serum dupilumab levels are associated with treatment response or adverse effects. Hence researchers have conducted a clinical, prospective, observational cohort study to evaluate serum dupilumab levels at 16 weeks of treatment and to explore the association of serum dupilumab levels with treatment response and adverse effects in patients with AD at the University Medical Center Utrecht in the Netherlands. 

By using data from the prospective BioDay Registry all adult patients with AD who started dupilumab treatment and for whom a serum sample was available at 16 weeks of treatment were taken into the study. As per the BioDay protocol, patients received a loading dose of dupilumab 600 mg subcutaneously, followed by 300 mg every other week. Patients who had a dose adjustment or discontinued treatment before 16 weeks of treatment were excluded.

Using the Eczema Area and Severity Index (EASI) disease severity of AD was assessed at baseline and weeks 16 and 52. Response to treatment was defined as the percent reduction in EASI score vs the baseline score and as an absolute EASI cutoff score of 7 or lower (controlled AD). Adverse effects were recorded during the first year. At 16 weeks, dupilumab serum levels and treatment responses were measured and analyzed. Multivariate logistic regression modeling was used to determine the prediction of response (EASI 90; EASI ≤7) and adverse effects at 52 weeks, with serum dupilumab levels at 16 weeks in the presence of the covariates age and sex.

Results: 

• Among the total of 295 patients with a mean [SD] age, of 41.5 [15.9] years, there were 170 [57.6%] men.
• The median drug level was 86.6 μg/mL at 16 weeks of treatment.
• There were no significant differences in serum dupilumab levels between responder statuses (EASI, <50, 50, 75, or 90) at week 16.
• Nonsignificant odds ratios (ORs) were observed for serum dupilumab levels at 16 weeks regarding the prediction of long-term response and adverse effects in Multivariate logistic regression analysis. 

The study results show no association between serum dupilumab levels at week 16 and treatment response and adverse effects. Target availability of the interleukin-4 receptor subunit α may have an interpatient variability producing heterogeneity in response. 

Further reading: Spekhorst LS, de Graaf M, Loeff F, et al. Association of Serum Dupilumab Levels at 16 Weeks With Treatment Response and Adverse Effects in Patients With Atopic Dermatitis: A Prospective Clinical Cohort Study From the BioDay Registry. JAMA Dermatol. Published online November 02, 2022. doi:10.1001/jamadermatol.2022.4639