680 - Efficacy of lebrikizumab in adults and adolescents with moderate-to-severe atopic dermatitis by age of onset: analysis of two phase 3 clinical trials

Abstract Introduction/Background Atopic dermatitis (AD) has different clinical presentations, pathophysiology, comorbidity frequencies, and genetic profiles in adult-onset vs childhood-onset disease. Based on these differences, it is plausible that treatment response would also be different between adult- and childhood-onset AD. Lebrikizumab, a novel, high affinity monoclonal antibody, selectively targeting IL-13 with high affinity and slow dissociation rate, has been approved in the EU, UK, and Japan and is under investigation in the US and elsewhere for the treatment of moderate-to-severe AD. Objectives To evaluate the Week-16 efficacy of lebrikizumab monotherapy by age of AD onset in adults and adolescents with moderate-to-severe AD from ADvocate1 (NCT04146363) and ADvocate2 (NCT04178967), identically-designed, randomized, double-blind, placebo-controlled phase 3 trials. Methods In ADvocate1 and ADvocate2, eligible patients were randomly allocated 2:1 to receive lebrikizumab 250 mg or placebo every 2 weeks. The date of AD onset was collected, and age of onset was calculated accordingly. Patients were stratified by age of AD-onset as ≤2, >2-to-<18, and ≥18 years. Efficacy was assessed at Week 16 with the proportion of patients with Investigator’s Global Assessment score of 0 or 1 with ≥2-point improvement (IGA 0,1; the trials’ primary endpoint); ≥75% (EASI 75) and ≥90% (EASI 90) improvement in the Eczema Area and Severity Index from baseline; ≥4-point Pruritus Numeric Rating Scale (NRS) improvement from baseline (with baseline score ≥4), and percentage change in total EASI from baseline. Data from patients who received topical or systemic rescue medication or discontinued treatment due to lack of efficacy were imputed as nonresponders or set to baseline values. Data from patients who discontinued treatment for other reasons were set to missing and analyzed by multiple imputation. This was a post-hoc analysis conducted on the modified, pooled intent-to-treat population. Treatment-by-age subgroup interaction was assessed with logistic regression. Binary outcomes were analyzed by the Cochran-Mantel-Haenszel method, and continuous outcomes were analyzed with ANCOVA. Results At baseline, the numbers of patients treated with lebrikizumab and placebo, respectively, were 215 and 117 in the ≤2 years AD-onset subgroup, 178 and 103 in the >2-to-<18 years subgroup, and 171 and 67 in the ≥18 years subgroup. At baseline, the percentages of patients with ≥1 atopic comorbidity were 81% in the ≤2 years subgroup, 74% in the >2-to-<18 years subgroup, and 58% in the ≥18 years subgroup. At Week 16, treatment-by-age subgroup interactions were not significant at the 0.10 level for IGA 0,1; EASI 75; EASI 90; and Pruritus NRS 4-pt improvement. Within each subgroup, a higher proportion of lebrikizumab-treated compared with placebo-treated patients (p<0.001) achieved IGA 0,1 responses (≤2 years: 41% vs. 12%; >2-to-<18 years: 35% vs. 12%; ≥18 years: 38% vs. 12%), EASI 75 responses (≤2 years: 57% vs. 17%; >2-to-<18 years: 51% vs. 16%; ≥18 years: 58% vs. 20%), and EASI 90 responses (≤2 years: 38% vs. 10%; >2-to-<18 years: 32% vs. 9%; ≥18 years: 33% vs. 8%). Additionally, the least-squares mean percentage change from baseline in total EASI score for lebrikizumab and placebo, respectively, was -65% and -26% in the ≤2 years subgroup, -60% and -26% in the >2-to-<18 years subgroup, and -63% and -30% in the ≥18 years subgroup (p<0.001 for lebrikizumab vs. placebo in all subgroups). The proportion of lebrikizumab-treated patients who reported ≥4-point improvement in Pruritus NRS from baseline (baseline ≥4) was greater compared with placebo-treated patients ([N]; ≤2 years: 43% [201] vs. 11% [108]; >2-to-<18 years: 41% [161] vs. 14% [96]; ≥18 years: 45% [154] vs. 12% [60]; p<0.001). Conclusions Regardless of age of AD onset, lebrikizumab was associated with significant improvements in AD signs and symptoms compared with placebo over 16 weeks of treatment.