Efficacy and Safety of 611 in Chinese Adults with Moderate-to-Severe Atopic Dermatitis: Results from a Phase II Trial.

Introduction: Atopic dermatitis (AD) is a chronic inflammatory skin disease. 611, a humanized monoclonal antibody, selectively targets the interleukin (IL)-4 receptor alpha, thereby inhibiting the signaling of both interleukin (IL)-4 and IL-13. This phase 2 study aimed to evaluate the efficacy and safety of 611 in Chinese adults with moderate-to-severe AD.

Methods: This randomized, double-blind, placebo-controlled phase 2 study was conducted between October 2022 and September 2023. Eligible patients with moderate-to-severe AD were randomly assigned in a 1:1:1 ratio to receive 611 at a dose of either 300 mg (loading dose of 600 mg) every 2 weeks (Group A) or 300 mg (loading dose of 600 mg) every 4 weeks (Group B), or placebo every 2 weeks for 16 weeks, followed by an 8-week follow-up period. The primary efficacy endpoint was the proportion of patients achieving at least a 75% reduction in the Eczema Area and Severity Index (EASI-75) score at week 16. The safety and pharmacodynamics were also assessed.

Results: After 16 weeks of treatment, 60.0% of patients in Group A and 48.8% in Group B achieved EASI-75, both significantly higher than the placebo group (15.6%, p < 0.01). Additionally, 611 at both doses significantly improved the Investigator's Global Assessment (IGA) scores, peak pruritus numerical rating scale (NRS), and other efficacy endpoints. Patients receiving 611 demonstrated significant reductions in serum thymus activation-regulated chemokine (TARC) and total serum immunoglobulin E (IgE) levels. The incidence of treatment-emergent adverse events (TEAEs) was similar across all dosage groups. The most common 611-related TEAE is upper respiratory tract infections. No new safety concerns were identified.

Conclusion: 611 demonstrated a high efficacy and a favorable safety profile in patients with moderate-to-severe AD.

Trial Registration: ClinicalTrials.gov, NCT05544591.