Lebrikizumab Demonstrates Significant Efficacy Versus Placebo Across Racial and Ethnic Subgroups in Patients with Moderate-to-severe Atopic Dermatitis

Introduction/Background The efficacy of monotherapy lebrikizumab to treat moderate-to-severe atopic dermatitis (AD) has been established in phase 3 studies. Disease characteristics and efficacy outcomes may vary among racial and ethnic subgroups. Objectives To report the week 16 efficacy results of lebrikizumab-treated patients by racial and ethnic subgroups from ADvocate1 (NCT04146363) and ADvocate2 (NCT04178967). Methods Eligible patients were randomized 2:1 to receive lebrikizumab or placebo every 2 weeks. Other AD treatments during this induction period were prohibited. The week 16 efficacy endpoints reported here include Investigator’s Global Assessment 0 or 1 with ≥2-point improvement from baseline (IGA 0/1), ≥75% improvement in the Eczema Area and Severity Index from baseline (EASI 75), ≥90% improvement in EASI from baseline (EASI 90), and ≥4-point Pruritus Numeric Rating Scale (NRS) improvement from baseline. Race and ethnicity were self-reported. Data were collected globally. Data were pooled from ADvocate1 (Intent to Treat [ITT]) and ADvocate2 (modified ITT). Subsequent data from patients who received topical or systemic rescue medication or discontinued treatment due to lack of efficacy were imputed as nonresponders. Subsequent data from patients who discontinued treatment for other reasons were set to missing. Missing data were handled with multiple imputation. Logistic regression tested the interaction between the treatment by subgroup. P>0.1 indicated consistent treatment effect of lebrikizumab versus placebo across subgroups. For each outcome, the Cochran-Mantel-Haenszel method evaluated treatment effect within each subgroup after adjusting for stratification factors. Results Most patients (818/851 [96.1%]) were Asian (192 [22.6%]), Black/African American (84 [9.9%]), or White (542 [63.7%]). Due to the low proportion of patients identifying as another racial category (33/851 [3.9%]) including American Indian or Alaska Native, Native Hawaiian or other Pacific Islander, multiple, other, and not reported, only results of Asian, Black/African American, and White subgroups are reported. In patients with completed ethnicity data (N=839), 10.8% (91/839) identified as Hispanic/Latino and 89.2% (748/839) identified as not Hispanic/Latino. At baseline, Asian patients reported a numerically earlier mean age of AD onset (8.3 years) compared to White (16.5 years) and Black/African American (16.9 years) patients. A numerically greater proportion of Asian patients presented with severe (IGA 4) disease at baseline (49.5%) and prior use of systemic treatment for AD (75.5%) compared with White (35.1% and 51.1%, respectively) and Black/African American (33.3% and 36.9%, respectively) patients. At week 16, no significant treatment differences were observed for the proportion of patients achieving or reporting IGA 0/1, EASI 75, EASI 90, or ≥4-point Pruritus NRS improvement across racial or ethnic subgroups (p>0.1). In Asian patients, a higher proportion treated with lebrikizumab vs placebo (p<0.001) achieved or reported IGA 0/1 (25.1%, 4.1%), EASI 75 (45.5%, 8.5%), EASI 90 (26.5%, 4.3%), and Pruritus NRS ≥4-point improvement (36.4%, 5.7%). In Black/African American patients, a greater proportion treated with lebrikizumab versus placebo achieved or reported IGA 0/1 (33.2%, 13.2%) EASI 75 (51.7%, 18.8%), EASI 90 (26.9%, 13.2%), and ≥4-point Pruritus NRS improvement (41.7%, 17.4%). No statistical comparisons were performed due to limited sample size. In White patients treated with lebrikizumab, statistical significance was observed versus placebo (p<0.001) for IGA 0/1 (43.3%, 14.1%), EASI 75 (59.7%, 20.4%), EASI 90 (38.3%, 10.9%), and Pruritus NRS ≥4-point improvement (45.9%, 14.8%). Significant and similar differences with lebrikizumab-treatment versus placebo were observed among IGA 0/1, EASI 75, and ≥4-point Pruritus NRS improvement in Hispanic/Latino (p<0.05) and non-Hispanic/Latino (p<0.001) patients. The proportion of lebrikizumab-treated patients achieving EASI 90 versus placebo was numerically greater in Hispanic/Latino patients (p=0.057) but only reached statistical significance in non-Hispanic/Latino patients (p<0.001). Conclusions In ADvocate1 and ADvocate2, lebrikizumab was effective across racial and ethnic subgroups for the treatment of moderate-to-severe AD after 16 weeks of monotherapy treatment.