Introduction: To ensure minimal residual disease and to prevent relapses, recently published consensus reports have defined optimal long-term treatment targets for atopic dermatitis (AD).1,2 Tralokinumab, a monoclonal antibody specifically neutralizing interleukin-13, is approved for the treatment of moderate-to-severe AD. ECZTEND (NCT03587805) is an ongoing open-label, 5-year extension trial investigating the long-term safety and efficacy of tralokinumab 300 mg every other week (Q2W) plus optional topical corticosteroids (TCS). Objectives of this analysis were to determine the proportion of patients treated for up to 4 years with tralokinumab in AD clinical trials who: 1) exhibit stable improvement, with no or minimal fluctuations, in lesion extent and severity long-term (ie, response in ≥80% of attended visits), and 2) exhibit a stable long-term composite response (ie, up to 4 years of tralokinumab treatment and response in ≥80% of attended trial visits) in signs and symptoms of AD, and quality of life based on recent treat-to-target recommendations (EASI ≤7 and either DLQI ≤5 or Itch NRS ≤4). Methods: This post hoc analysis included 347 patients who were continuously treated with tralokinumab for 52 weeks in the identically designed phase 3 monotherapy trials ECZTRA 1&2 and subsequently for up to 152 weeks in ECZTEND as of the April 30, 2022 data cutoff. Stability of long-term response, with no or minimal fluctuations, was defined as meeting the target endpoints at ≥80% of attended visits between Weeks 16-152 in ECZTEND. Endpoints analyzed were EASI ≤7, EASI ≤2, and a composite long-term treatment target: EASI ≤7 and either DLQI ≤5 or worst weekly pruritus NRS ≤4. Results: A stable EASI ≤7 response (at ≥80% of attended visits) was observed in 70.2% (233/332) of tralokinumab-treated patients over Weeks 16-152 of ECZTEND. A stable EASI ≤2 response was observed in 34.0% (113/332) of patients, and a long-term optimal composite target, EASI ≤7 and either DLQI ≤5 or Itch NRS ≤4, was observed in 60.5% (201/332) of patients. Conclusions: High proportions of clinical trial patients maintained stable responses, with no or minimal fluctuations in efficacy, with continued tralokinumab 300 mg Q2W plus optional TCS for up to 4 years of treatment.