A Study to Evaluate ABT-494 (Upadacitinib) in Adults With Moderate to Severe Atopic Dermatitis

The study was to include a 16-week double-blind treatment period (Period 1) and a 72-week double-blind treatment period (Period 2) for a total of 88 weeks of treatment. Participants who met eligibility criteria were to be randomized in a 1:1:1:1 ratio to one of the four treatment groups. Participants who completed Period 1 were re-randomized at Week 16 into a 72-week double-blind, placebo-controlled treatment period (Period 2) in a 1:1 ratio: * Group 1: Upadacitinib 7.5 mg once daily (QD) (Day 1 to Week 16) → upadacitinib 7.5 mg QD or placebo (Week 16 - and thereafter) * Group 2: Upadacitinib 15 mg QD (Day 1 to Week 16) → upadacitinib 15 mg QD or placebo (Week 16 and thereafter) * Group 3: Upadacitinib 30 mg QD (Day 1 to Week 16) → upadacitinib 30 mg QD or placebo (Week 16 - and thereafter) * Group 4: Matching placebo (Day 1 to Week 16) → upadacitinib 30 mg QD or placebo (Week 16 and thereafter) In Period 1, discontinuation from study drug was mandatory for any participant with an Eczema Area and Severity Index (EASI) score worsening of 25% or more compared with their Baseline EASI score at any 2 consecutive scheduled study visits from Week 4 to Week 12. In Period 2, blinded rescue therapy with upadacitinib 30 mg QD was provided after the first instance of a \< EASI 50 response starting at the Week 20 visit (4 weeks after re-randomization into Period 2) for the remainder of the study.