A Open-label Study to Assess the Long-term Safety of Difamilast Ointment 1% in Mild to Moderate Atopic Dermatitis

Important Inclusion Criteria:

1. Subjects who are male or female ≥2 years of age at Screening (Visit 1).

2. Subjects who have a diagnosis of AD based on the American Academy of Dermatology ADdiagnostic criteria

3. Subjects who have had a diagnosis of AD for at least 3 months prior to Screening .

4. Subjects who have an IGA of mild or moderate AD Severity and treatable body surfacearea (BSA) ≥3%at Baseline if not previously enrolled in study MEDI-MM36-301 OR b.IGA ≤ 3, with no minimum BSA and completed through Week 4/EOT Visit 6 of the studyMEDI-MM36-301.

5. Subject is willing and able to comply with all study-related procedures, including,but not limited to, application of the study drug, and visit requirements.

Important Exclusion Criteria:

1. Subjects who have an AD flare (defined as rapid intensification of AD) within 28days prior to Screening or Baseline (except for those previously enrolled in StudyMEDI-MM36-301) or history of consistent requirement for high-potency topicalcorticosteroids to manage AD signs and symptoms.

2. Subjects who have an active or acute skin infection (eg, herpes simplex, herpeszoster, or chicken pox), and/or clinically infected AD

3. Subjects with significant systemic or localized infection

4. Subjects with minimal/mild depression and suicidal ideation

5. Subjects using restricted medications, biologics and alternative therapies, or usinginvestigational drug