Laboratory Parameters in Adolescent Patients Aged 12–17 with Moderate-to-Severe Atopic Dermatitis Treated with Tralokinumab Up to Week 52: Results from the Phase 3 ECZTRA 6 Trial

Abstract

Introduction: Tralokinumab, a high-affinity, monoclonal antibody that targets IL-13, is approved in the EU and Canada for adolescents (aged ≥12 years) with inadequately controlled moderate-to-severe atopic dermatitis (AD), and it does not require laboratory monitoring. The phase 3 ECZTRA 6 (NCT03526861) clinical trial demonstrated efficacy and safety up to 52 weeks in that population.

Objective/Purpose: To further characterize the safety profile of tralokinumab by evaluating laboratory parameters of adolescents in the ECZTRA 6 trial.

Methods: ECZTRA 6 subjects received tralokinumab 150mg (n=98), 300mg (n=97) or placebo (n=94) every 2 weeks (Q2W) from week 0–16 after a loading dose at week 0 (twice the subsequent dose), and then randomized to maintenance [original tralokinumab dose either Q2W or every 4 weeks (Q4W) or placebo Q2W] or open-label (tralokinumab 300mg Q2W) until week 52. Laboratory parameters included hematology, serum biochemistry, and urinalysis throughout the trial (weeks 0, 8, 16, 28, and 52).

Results: Overall (n= 289 subjects), laboratory baseline parameters were similar across treatment groups. Mean and median changes of most hematology parameters showed minor fluctuations within the normal ranges through week 52, except for eosinophils. At baseline, elevated mean eosinophil counts (>0.5 10⁹/L) were observed for 40.8% (tralokinumab 150mg), 48.5% (tralokinumab 300mg), and 43.6% (placebo) of subjects in each respective treatment group. Some tralokinumab-treated patients had small transient increases in eosinophils (maximum mean change from baseline 0.2×10⁹/L) before week 16. Continued treatment with tralokinumab or placebo did not correspond with further increase in eosinophil levels over time, and no adverse events of eosinophilia were reported. Mean levels of most biochemistry parameters, including electrolytes, renal and liver function parameters, and lipid panel, were within normal range at baseline, and mean and median changes showed minor fluctuations within normal ranges in all treatment arms. Mean lactate dehydrogenase levels were around or above the upper limit of normal at baseline and decreased to within the normal ranges during the trial across all groups. Overall, no clinically meaningful differences were observed in hematology, biochemistry, or urinalysis parameters between active treatment groups or placebo.

Conclusions: Similar to findings in adult trials, no meaningful changes in laboratory parameters were observed in adolescents through week 52 with tralokinumab treatment. No routine laboratory monitoring is needed for adult or adolescent AD patients treated with tralokinumab.