Long-Term Efficacy and Safety of Stapokibart in Adults with Moderate-to-Severe Atopic Dermatitis: An Open-Label Extension, Nonrandomized Clinical Trial.

Background: Stapokibart/CM310, a humanized monoclonal antibody targeting the interleukin-4 receptor α chain, has shown promising treatment benefits in patients with moderate-to-severe atopic dermatitis in previous phase II clinical trials.

Objective: We aimed to evaluate the long-term efficacy and safety of stapokibart in adults with moderate-to-severe atopic dermatitis.

Methods: Enrolled patients who previously completed parent trials of stapokibart received a subcutaneous stapokibart 600-mg loading dose, then 300 mg every 2 weeks up to 52 weeks. Efficacy outcomes included the proportions of patients with ≥ 50%/75%/90% improvements from baseline of parent trials in the Eczema Area and Severity Index, Investigator's Global Assessment, and weekly average of the daily Peak Pruritus Numerical Rating Scale.

Results: In total, 127 patients were enrolled, and 110 (86.6%) completed the study. At week 52, the Eczema Area and Severity Index-50/75/90 response rates were 96.3%, 87.9%, and 71.0%, respectively. An Investigator's Global Assessment 0/1 with a ≥ 2-point reduction was achieved in 39.3% of patients at week 16, increasing to 58.9% at week 52. The proportions of patients with ≥ 3-point and ≥ 4-point reductions in the weekly average of daily Peak Pruritus Numerical Rating Scale scores were 80.2% and 62.2%, respectively, at week 52. Improvement in patients' quality of life was sustained over a 52-week treatment period. Treatment-emergent adverse events occurred in 88.2% of patients, with an exposure-adjusted event rate of 299.2 events/100 patient-years. Coronavirus disease 2019, upper respiratory tract infection, and conjunctivitis were the most common treatment-emergent adverse events.

Conclusions: Long-term treatment with stapokibart for 52 weeks showed high efficacy and good safety profiles, supporting its use as a continuous long-term treatment option for atopic dermatitis.

Clinical Trial Registration: ClinicalTrials.gov identifier: NCT04893707 (15 May, 2021).