Late-breaking positive phase 2a results were presented at AAD 2023.
LEO Pharma presented late-breaking phase 2a data on its investigational agent, LEO 138559, for the treatment of adults with moderate-to-severe atopic dermatitis at the 2023 American Academy of Dermatology (AAD) Annual Meeting in New Orleans, Louisiana.1 LEO 138559, a monoclonal antibody and an interleukin (IL)-22 receptor, demonstrated a significant improvement compared to placebo across multiple endpoints including Eczema Area and Severity Index (EASI)-75, EASI-90, EASI-100, and Validated Investigator Global Assessment Scale for Atopic Dermatitis (vIGA-AD) 0/1.
LEO 138559 is designed to block the IL-22RA1 receptor subunit, inhibiting the effect of the IL-22 cytokine associated with atopic dermatitis. Diamant Thaçi, MD, professor and head of the Comprehensive Center for Inflammation Medicine at the University of Lübeck in Germany, and presenter at the late-breaking AAD session, noted that LEO 138559 may also inhibit some effects of cytokines IL-20 and IL-24, but more research is needed to fully understand the connection.2 LEO 138559 does not bind to the IL-22 cytokine itself. The data presented at AAD are the first to be presented for an IL-22 receptor targeting antibody for the treatment of moderate-to-severe atopic dermatitis.
In total, 58 patients of the double-blind, placebo-controlled, multi-site phase 2a trial (NCT04922021) were randomized 1:1 (n=29 per arm) to receive either LEO 138559 dosed at 450 mg every other week (Q2W) or placebo, for 16 weeks. Results demonstrated that LEO 138559 dosed at 450 mg Q2W by subcutaneous injections for 16 weeks had a positive safety profile. LEO 138559 also showed significant improvement across EASI and vIGA-AD endpoints compared to placebo, including:
The most frequently reported adverse events of LEO 138559 compared to placebo were COVID-19 (13.8% vs 6.9%), dermatitis atopic (13.8% vs 13.8%), and upper respiratory tract infection (3.4% vs 10.3%).
Jörg Möller, executive vice president of global research and development at LEO Pharma is looking forward to the development of the phase 2b trial, after such positive results from phase 2a.