This is designed to assess the long-term safety and efficacy of lebrikizumab for moderate-to-severe atopic dermatitis. It will last up to 33 months.

Participants who have completed participation in a Dermira- or Lilly-sponsored lebrikizumab study (parent study), DRM06-AD04 (NCT04146363), DRM06-AD05 (NCT04178967), DRM06-AD06 (NCT04250337), DRM06-AD17 (NCT04250350) or DRM06- AD18 (NCT04626297), will be offered the opportunity to enroll in this study. Participants may either be blinded or not blinded, depending on their parent study assignment. This study will also be open to an additional approximately 100 participants in the United States (addendum) who have not completed participation in a Dermira- or Lilly-sponsored lebrikizumab study. Treatment will not be blinded. This study will also include an Addendum to extend the study treatment period by an additional 32 weeks and to add a treatment arm testing dosing every 8 weeks. This Addendum will apply to existing study participants in selected countries. Treatment will not be blinded.