This study is testing a new medicine called **ATI-045** and comparing it to a fake pill (placebo) to see if it helps people with moderate-to-severe **atopic dermatitis**. Atopic dermatitis is a skin condition that causes red, itchy patches. The study is **randomized** (participants are randomly assigned to either the medicine or placebo) and **double-blinded**, meaning neither the participants nor the researchers know who gets which treatment. To join, you must have had atopic dermatitis for at least 6 months, with no major flare-ups in the past month. You should also have a specific level of skin involvement (measured by **EASI** score and **BSA percentage**) and have tried regular treatments that didn't work well. Some treatments and medicines are not allowed before starting the study, such as certain antibiotics and topical treatments. Three key points: - The study is double-blinded and placebo-controlled, ensuring unbiased results. - Participants need to use a non-medicated moisturizer regularly during the study. - Avoid using specific medications and treatments weeks before starting the study. Make sure to talk to your doctor to see if this study is a good fit for you.