IGAxBSA composite for assessing disease severity and response in patients with atopic dermatitis

BACKGROUND: Accurate assessment of atopic dermatitis (AD) severity is critical when initiating and monitoring therapy. Use of existing research tools such as the Eczema Area and Severity Index (EASI) and Scoring Atopic Dermatitis (SCORAD) is complex and time‐consuming in clinical practice. A previous analysis found the product of validated Investigator’s Global Assessment (vIGA) and affected body surface area (BSA) to be an accurate and practical tool for routine assessment of paediatric AD. OBJECTIVE: To evaluate the IGAxBSA composite as an alternative to EASI or SCORAD for assessment of AD disease severity and disease responsiveness. METHODS: The relationship between IGAxBSA, EASI and SCORAD was assessed in a post hoc analysis of pooled data from the dupilumab clinical trial programme in adult and paediatric patients with moderate‐to‐severe AD who had received dupilumab or placebo, with or without topical corticosteroids (TCS). The trials are registered at ClinicalTrials.gov and EudraCT: LIBERTY AD SOLO 1 (NCT02277743, 2014‐001198‐15), LIBERTY AD SOLO 2 (NCT02277769, 2014‐002619‐40), LIBERTY AD SOLO‐CONTINUE (NCT02395133, 2014‐003384‐38), LIBERTY AD CHRONOS (NCT02260986, 2013‐003254‐24), LIBERTY AD CAFÉ (NCT02755649, 2015‐002653‐35), LIBERTY AD ADOL (NCT03054428, 2015‐004458‐16), LIBERTY AD PEDS (NCT03345914, 2016‐004997‐16), LIBERTY AD OLE (NCT01949311, 2013‐001449‐15) and LIBERTY AD PEDS OLE (NCT02612454, 2015‐001396‐40). RESULTS: Using datapoints from pooled dupilumab randomized controlled trials (n = 3473) and open‐label extension trials (n = 3045), we found that IGAxBSA correlated well with EASI and SCORAD, irrespective of treatment group and race (white, Asian, black). IGAxBSA correlated better with objective measures (EASI, SCORAD) than with patient‐ or caregiver‐reported subjective measures. IGAxBSA correlated strongly with EASI and SCORAD in assessing disease change over time (r = 0·90, r = 0·76, respectively; P < 0·0001), and concordance between IGAxBSA‐50/75/90 and EASI‐50/75/90 was excellent (88–94%). CONCLUSIONS: IGAxBSA is a valid alternative for assessment of AD disease severity and response over time, compared with EASI or SCORAD in patients with AD, irrespective of race.