A Study to Evaluate the Effectiveness and Safety of Topical OPA-15406 Ointment to Treat Participants With Atopic Dermatitis

A Phase 2 Multi-center, Randomized, Double-blind, Vehicle-controlled, Three-arm, Parallel Group Study to Assess the Safety, Tolerability, and Efficacy of Topical OPA-15406 Ointment, in Subjects With Mild/Moderate Atopic Dermatitis

The purpose of this study is to investigate the effectiveness and safety of 2 concentrations of OPA-15406 compared to vehicle in participants with atopic dermatitis (AD).

AD is a disease mainly characterized by pruritic eczema, and those with the disease experience repeated exacerbations and remissions. Therapeutic guidelines for the disease, currently being developed in many countries, all recognize AD as chronic eczema that is accompanied by the physiological dysfunction of the skin and in which inflammation is caused by various nonspecific stimuli or specific allergens. OPA 15406 is a type-4 phosphodiesterase (PDE4) inhibitor. PDE4 inhibitors are thought to be useful for allergic inflammatory diseases. This is a Phase 2 dose ranging study to evaluate the efficacy of two concentrations of OPA 15406 ointment compared to vehicle, when administered topically twice daily in participants with mild to moderate AD.

Inclusion Criteria:

• Participants 10-70 years of age
• Diagnosis of AD
• History of AD for at least 3 years
• AD affecting greater than or equal to 5% and less than or equal to 40% of total body surface area (BSA) at Baseline
• Investigator's Global Assessment of Disease Severity score of 2 (mild) or 3 (moderate) in the selected treatment area(s)

Exclusion Criteria:

• Contact or atopic dermatitis flare within 28 days of the Baseline (Day 1) visit.
• Concurrent diseases/conditions and history of other diseases/conditions in the selected treatment area(s) that may have an impact on the study assessments.