Atopic dermatitis (AD) is a skin condition that may cause a rash and itching due to inflammation of the skin. The purpose of this study is to evaluate the clinical efficacy and safety of single therapies and/or combination therapies for moderate to severe AD through multiple substudies. This study will consist of multiple sub-studies, Sub-Study 1 will have a randomized, placebo controlled period 1 followed by a lutikizumab treatment period 2 enrolling 80 participants at a 1 to 1 ratio. In Sub-Study 1, participants will receive subcutaneous (SC) injections of lutikizumab or matching placebo every other week for 16 weeks followed by an additional 32 weeks of subcutaneous (SC) injections of lutikizumab every other week for a total of 52 weeks. There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at a hospital or clinic and may require frequent medical assessments, blood tests, and biomarker collections.