OBJECTIVES : Severity of AD was measured in 2 phase 3 US studies in patients aged ≥2 years using the Investigator’s Static Global Assessment (ISGA), a 5-point FDA-recommended scale from 0 (clear) to 4 (severe). The Eczema Area and Severity Index (EASI), a validated scale ranging from 0-72, is used globally to assess AD severity in clinical trials. The objective was to translate ISGA scores into EASI scores, thereby aiding in the interpretability of the ISGA.

METHODS : Mapping of ISGA to EASI scores was performed through 70,000 random simulations using published EASI severity strata for global severity states (Leshem Y et al., 2015; Chopra R et al., 2017). ISGA scores were mapped for pooled data from crisaborole, 2%, phase 3 trials CORE-1 (NCT02118766) and CORE-2 (NCT02118792), which evaluated patients aged ≥2 years with mild-to-moderate AD (crisaborole, n=1016; vehicle, n=506; 86% children). Least squares mean (LSM) percentage change from baseline (%CFB; where negative=improving, positive=worsening) in EASI and proportion of patients with 50%, 75%, and 90% improvement (EASI-50, EASI-75, and EASI-90) on day 29 were computed.

RESULTS : At day 29, LSM (SE) for %CFB in mapped EASI from Leshem was −43.1% (4.6) (crisaborole) and −5.2% (8.4) (vehicle) (P<0.0001) and from Chopra was −26.3% (17) vs 45.2% (35) (P=0.0671). For proportion of patients with improvement, results for Leshem were: EASI-50, 68.8% (crisaborole) versus 54.0% (vehicle); EASI-75, 54.8% versus 40.5%; EASI-90, 38.9% versus 27.2%; P<0.0001 for each difference. Results for Chopra were: EASI-50, 72.1% (crisaborole) versus 57.6% (vehicle); EASI-75, 63.0% versus 47.8%; EASI-90, 55.0% versus 40.1%; P<0.0001 for each difference. Mapped EASI results were consistent with ISGA findings from the clinical trials. A limitation is that most patients in articles for EASI strata were adults.

CONCLUSIONS : Mapping of ISGA to EASI scores was investigated using data from clinical trials to present results in terms of the EASI.