Efficacy and Safety of LEO 152020 Tablets for the Treatment of Adults With Moderate to Severe Atopic Dermatitis

A Phase 2 Trial to Evaluate the Efficacy and Safety of Orally Administered LEO 152020 Tablets Compared With Placebo Tablets for up to 16 Weeks of Treatment in Adults With Moderate to Severe Atopic Dermatitis

This is an up to 22-week clinical study in adult participants with moderate to severe atopic dermatitis (AD).

The purpose of the study is to test a new tablet (LEO 152020) to see if it improves AD and what the side effects are when compared with a placebo tablet with no medical ingredient.

During the study, there will be a 16-week treatment period during which the participants will be asked to take the tablets. The participants will regularly visit the clinic for tests and the study doctor will evaluate their AD. The participants will also be asked to answer questions about their AD symptoms, itch, sleep, and quality of life.

Inclusion Criteria:

• Adult, age 18 years or older at screening.
• Diagnosis of chronic atopic dermatitis (AD).
• History of AD ≥1 year prior to baseline.
• Recent (within 6 months prior to baseline) documented history of inadequate response to topical AD treatments or subject for whom topical AD treatments are medically inadvisable.
• 7.1≤ Eczema Area and Severity Index (EASI) ≤50 at baseline.
• Validated Investigator Global Assessment Scale for Atopic Dermatitis (vIGA-AD) score ≥3 at baseline.

Exclusion Criteria:

• Previous treatment with an oral histidine 4 receptor (H4R) antagonist (including LEO 152020) within 6 months prior to baseline.
• Previous treatment with 3 or more systemic AD treatments prior to screening.
• Women who are pregnant, intend to become pregnant, or are lactating.