Stapokibart (CM310) in patients with uncontrolled seasonal allergic rhinitis (PHECDA): Rationale and design of a multicentre, randomized, double-blind, placebo-controlled study.

Background: Seasonal allergic rhinitis (SAR) is a global health issue, and the current standard of care (SoC) has limited effectiveness in controlling the disease. There is a need for innovative treatments to better manage uncontrolled SAR and advance beyond the uniform SoC, and biologics targeting type 2 inflammation driving allergic rhinitis is promising. Objective: To evaluate the efficacy and safety of Stapokibart, a humanized monoclonal antibody targeting interleukin-4 receptor subunit alpha, as an add-on therapy in patients with uncontrolled SAR. Methods: The PHECDA is a multicenter, randomized, double-blind, placebo-controlled, phase 3 clinical study designed to evaluate the efficacy and safety of Stapokibart in treating uncontrolled SAR in adults. Conducted across 18 centers in China during the pollen season, the study plans to recruit 108 adult patients with moderate to severe nasal symptoms despite receiving SoC during the previous seasonal pollen period, along with a 1-week run-in period and a baseline blood eosinophil count of at least 300 cells·μL Results: This article outlines the methodology utilized in a multicenter trial studying Stapokibar for seasonal allergic rhinitis, with expectations to discuss its significant effects in subsequent analyses based on trial outcomes. Conclusion: The PHECDA study is for the first time to provide insight into the efficacy and safety of a seasonal add-on Stapokibart for patients with uncontrolled SAR during pollen exposure. Trial registration: NCT05908032.