A Phase 3, Randomized, 52-week, Placebo-controlled, Double-blind Study With Rerandomization to Assess the Efficacy, Safety, and Tolerability of Rocatinlimab (AMG 451) in Adolescent Subjects With Moderate-to-severe Atopic Dermatitis (AD) (ROCKET-ASTRO)

This study is investigating a new medication called rocatinlimab, which has the code name AMG 451. It's designed for teenagers who have moderate to severe atopic dermatitis, which is the most common type of eczema. Eczema can cause very itchy, dry, and inflamed skin, and for some, it can be quite troublesome and affect their daily lives. The aim of this study is to see if this new medicine can help improve these symptoms and make living with eczema easier.

This is a 'Phase 3' study, which means the medicine has already been through earlier tests and shown some promise. Now, researchers need to confirm if it genuinely works well and is safe for a larger group of people. Participants will be randomly assigned to either receive the new medicine or a 'placebo' – this is an inactive substance, like a sugar pill, that looks the same as the real medicine. This method is important for making sure any improvements seen are definitely due to the medicine and not just other factors. Neither the participants nor their doctors will know who is getting which treatment, which helps keep the study fair and unbiased.

The study will last for 52 weeks, which is a full year. During this time, the research team will closely monitor changes in eczema symptoms, such as how much the skin has improved, how much itching has reduced, and if any pain is felt. By carefully comparing the group receiving the medicine with the group receiving the placebo, the researchers can understand how effective rocatinlimab is and if it has any side effects. After 24 weeks, some participants might be 'rerandomised,' which means their treatment might change based on their progress, particularly for those on the placebo who still need help.