Abstract Introduction/Background Atopic dermatitis (AD) is a chronic, relapsing, inflammatory skin disease characterized by intense itch and eczematous skin lesions, impacting individuals at any age. There is a need for AD treatments that provide rapid itch relief and skin clearance that are safe for long-term use. Upadacitinib is a selective, reversible oral Janus kinase 1 (JAK1) inhibitor approved in multiple countries for the treatment of moderate-to-severe AD in adults and adolescents. Objectives We evaluated the long-term safety for up to 5 years of upadacitinib 15 mg and 30 mg use in adolescents and adults with moderate-to-severe AD, based on the results of integrated data from three ongoing global pivotal Phase 3 studies. Materials & Methods The Measure Up 1, Measure Up 2, and AD Up studies are ongoing pivotal Phase 3, randomized, placebo-controlled, multicenter studies evaluating the safety and efficacy of upadacitinib 15 mg and upadacitinib 30 mg in adolescents and adults with moderate-to-severe AD. Patients were randomized 1:1:1 to receive oral upadacitinib 15 mg, upadacitinib 30 mg, or placebo once daily alone (Measure Up 1 and 2) or with concomitant topical corticosteroids (AD Up). At Week 16, patients receiving upadacitinib 15 mg or 30 mg during the double-blinded period continued their assigned treatment in the blinded extension (BE) period, whereas patients receiving placebo were re-randomized 1:1 to receive either upadacitinib 15 mg or 30 mg in the BE period (upadacitinib treatment for up to 260 weeks). Results A total of 2683 patients (2154 adults, 529 adolescents) who received at least 1 dose of upadacitinib (15 mg,1337; 30 mg,1346) were included in the integrated analysis. Treatment-emergent adverse events of special interest (AESI) were analyzed as exposure-adjusted rates per 100 patient-years (PY) for the entire treatment period to adjust for potentially different durations of follow-up. Rates of AESIs were similar at the 1-year analysis and up to 5-year analysis for upadacitinib for: serious infections, 15 mg, 2.3 (1 yr) and 2.2 (5 yrs)/30 mg, 2.8 (1 yr) and 2.6 (5 yrs); opportunistic infections, 15 mg, 1.6 (1 yr) and 1.7 (5 yrs)/30 mg, 1.9 (1 yr) and 2.2 (5 yrs); active tuberculosis, <0.1 at both timepoints for both doses; herpes zoster, 15 mg, 3.5 (1 yr) and 3.1 (5 yrs)/30 mg, 5.2 (1 yr) and 5.5 (5 yrs); non-melanoma skin cancer (NMSC), 15 mg, 0.3 (1 yr) and 0.4 (5 yrs)/30 mg, 0.4 (1 yr) and 0.3 (5 yrs); malignancy excluding NMSC, 15 mg, 0.1 (1 yr) and 0.3 (5 yrs)/30 mg, 0.5 (1 yr) and 0.4 (5 yrs); gastrointestinal perforations, 15 mg, 0 at both time points/30 mg, 0 (1 yr) and <0.1 (5 yrs); adjudicated major adverse cardiovascular events (MACE), 15 mg, 0.1 (1 yr) and 0.2 (5 yrs)/30 mg, <0.1 at both timepoints; adjudicated venous thromboembolic events (VTE), <0.1 for both doses at 1 year and 0.1 for both doses at 5 years. Rates of adverse events leading to death were: 15 mg, 0 (1 yr) and <0.1 (5 yrs)/30 mg, <0.1 at both timepoints. Rates of serious infection at both timepoints and doses remained low (<3.0 E/100PYs). Upadacitinib was well-tolerated by both adults and adolescents. Conclusions The integrated analysis of long-term safety data for up to 5 years indicates that rates of AESIs remained low throughout treatment with upadacitinib 15 mg or 30 mg among adults and adolescents with moderate-to-severe AD. There were no new safety risks. The current safety analysis continues to support a favorable benefit-risk profile of upadacitinib in the treatment of adults and adolescents with moderate-to-severe AD for up to 5 years of treatment, including over 7000 years of patient exposure.