A Study to Evaluate Rocatinlimab (AMG 451) in Adolescent Participants With Moderate-to-severe Atopic Dermatitis (AD)

The purpose of this study is to evaluate the efficacy and safety of rocatinlimab in monotherapy and combination therapy treatment in adolescent participants.

Inclusion Criteria: * Age ≥ 12 to \< 18 years at Day 1. * Diagnosis of AD (according to American Academy of Dermatology Consensus Criteria \[Eichenfield et al, 2014\]) that has been present for at least 12 months before signing of informed consent. * Body weight ≥ 40 kg at screening. * History of inadequate response to TCS of medium to higher potency (with or without TCI). * EASI score ≥ 12 at initial screening. * EASI score ≥ 16 at Day 1. * vIGA-AD score ≥ 3. * ≥10% body surface area of AD involvement. * Worst pruritus NRS ≥ 4. Exclusion Criteria: * Treatment with a biological product within 12 weeks or 5 half-lives, whichever is longer, prior to Day 1. * Treatment with any of the following medications or therapies within 4 weeks or 5 half-lives, whichever is longer, prior to Day 1: 1. Systemic corticosteroids 2. Non-biologic, non-targeted systemic immunosuppressants 3. Phototherapy 4. Oral or Topical Janus kinase inhibitors * Treatment with any of the following medications or therapies within 1 week, prior to Day 1: 1. TCS of any potency 2. TCI 3. Topical phosphodiesterase 4 inhibitors 4. Other topical immunosuppressive agents