Efficacy and Safety of Tralokinumab Across Racial Subgroups in Adults with Moderate-to-Severe Atopic Dermatitis: Post Hoc Analysis of Phase III Trials

Abstract

Background

Differences in atopic dermatitis (AD) prevalence, clinical presentation, and pathophysiology have been reported in different ethnic/racial groups; however, clinical trial data for patients with skin of color are limited. Tralokinumab is a monoclonal antibody that specifically targets interleukin-13, a key driver of AD.

Objectives

To investigate the efficacy and safety of tralokinumab, and examine AD biomarker expression at baseline and week 16, by self-reported racial subgroup (Asian, Black, and White) in patients with moderate-to-severe AD.

Methods

Post hoc analyses were conducted by racial subgroup using data from four phase 3 trials: placebo-controlled parent trials ECZTRA 1, 2, and 3 and the open-label extension trial ECZTEND. Endpoints included Investigator’s Global Assessment (IGA) 0/1, 75% improvement in Eczema Area and Severity Index (EASI-75), and adverse events. In ECZTRA 1, serum and skin samples were analyzed for biomarker expression by immunoassay and Staphylococcus aureus (S. aureus) abundance by quantitative polymerase chain reaction (qPCR).

Results

A total of 1876 patients pooled from ECZTRA 1/2/3 (Asian/Black/White N = 407/134/1335) and 1392 patients from ECZTEND (Asian/Black/White N = 203/108/1081) were included. Baseline characteristics were largely balanced between treatment groups and racial subgroups, although AD severity was more moderate in Black patients and regional differences were observed. At week 16 of ECZTRA 1/2/3, tralokinumab improved efficacy outcomes, including IGA 0/1 and EASI-75, relative to placebo across all subgroups. Further improvements beyond week 16 were observed with continued tralokinumab treatment, including 78%, 88%, and 83% of Asian, Black, and White patients, respectively, achieving EASI-75 at week 56 of ECZTEND (corresponding to up to 2 years total tralokinumab treatment). At baseline, serum biomarker levels were elevated in Asian patients from Japan compared with other subgroups, while Asian patients from USA/Europe had lower S. aureus abundance, when adjusting for IGA. The safety profile of tralokinumab was comparable to placebo, and serious adverse events and adverse events leading to treatment discontinuation were rare, across racial subgroups.

Conclusions

Tralokinumab was well-tolerated and improved signs, symptoms, and biomarkers in patients with moderate-to-severe AD at 16 weeks across the racial subgroups studied, with further improvement in response rates up to 2 years of treatment.

Clinical Trial Registration

ClinicalTrials.gov identifiers: NCT03131648 (registered 24 April 2017), NCT03160885 (registered 18 May 2017), NCT03363854 (registered 01 December 2017), and NCT03587805 (registered 03 July 2018).