Management of moderate-to-severe atopic dermatitis (AD) needs long-term therapy. Stapokibart is a humanized monoclonal antibody targeting interleukin-4 receptor α subunit (IL-4Rα), a shared receptor for IL-4 and IL-13 which are key pathogenic drivers of AD. In a pivotal phase 3 trial (NCT05265923), significant higher proportions of adult AD patients receiving stapokibart than placebo achieved ≥75% improvement from baseline in Eczema Area and Severity Index (EASI-75; 66.9% vs. 25.8%) and Investigator's Global Assessment (IGA) score of 0/1 with ≥2-point reduction (44.2% vs. 16.1%) at Week 16. Herein, we report long-term (52 weeks) efficacy and safety of stapokibart from this trial. After 16-week double-blind treatment completed, patients in both stapokibart and placebo groups entered a 36-week maintenance treatment period and received stapokibart 300 mg every 2 weeks. Concomitant use of topical medications for AD was permitted throughout the maintenance period. Of 476 patients entering maintenance period, 430 completed the treatment. At Week 52, EASI-75 was achieved in 92.5% of patients continuing stapokibart and 88.7% of those switching from placebo to stapokibart, respectively; an IGA score of 0 or 1 with a ≥2-point reduction was achieved in 67.3% and 64.2% of patients, respectively; a ≥4-point reduction in weekly average of daily Peak Pruritus Numerical Rating Scale (PP-NRS) was achieved in 67.3% and 60.5% of patients, respectively. Over the 52-week treatment period, 88.1% of patients reported treatment-emergent adverse events, most were mild or moderate. Long-term treatment with stapokibart demonstrated a sustained efficacy and favorable safety profile in adults with moderate-to-severe AD.