Anti-thymic stromal lymphopoietin monoclonal antibody in patients with chronic rhinosinusitis with nasal polyps (DUBHE): Rationale and design of a multicenter, randomized, double-blind, placebo-controlled study.

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) has a complex pathogenesis and is difficult to treat, which brings a huge economic burden to society. Despite all the progress in the treatment of CRSwNP, some patients with CRSwNP still experience recurrence. Therefore, there is an urgent need to develop novel drugs and treatments for CRSwNP. Thymic stromal lymphopoietin (TSLP) is produced by epithelial cells and mediates type 2 and nontype 2 inflammation through various downstream cellular immune and inflammatory pathways. Anti-TSLP treatment with tezepelumab has been proven to be effective in treating patients with uncontrolled asthma, regardless of their peripheral blood eosinophil levels being low or high. However, there is no relevant research on the usage of anti-TSLP monoclonal antibodies for the treatment of uncontrolled CRSwNP.

Objective: This is the first phase Ib/IIa study for subjects with uncontrolled CRSwNP, aiming to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, immunogenicity, and preliminary efficacy of multiple ascending doses (MAD) of anti-TSLP monoclonal antibody.

Methods: The DUBHE is a multicenter, randomized, double-blind, placebo-controlled, phase Ib/IIa clinical study. The study will be composed of 3 periods: a screening/run-in period of 4 weeks, a treatment period of 52 weeks (16 weeks of double-blind treatment period +36 weeks of open-label treatment period), and a safety follow-up period of 12 weeks. No more than 113 subjects with uncontrolled CRSwNP will be divided into 4 groups to receive different doses of CM326 or placebo treatments (55 mg every two weeks [Q2W] group, 110 mg Q2W group, 220 mg Q2W group, and 220 mg every four weeks [Q4W] group). Enrolled patients will be stratified by tissue eosinophil count (TEC).

Results: The safety of the monoclonal antibody that targets TSLP in uncontrolled CRSwNP and its preliminary efficacy at 16 weeks of treatment.

Conclusion: In this study, for the first time, the safety and preliminary efficacy of MAD of CM326 will be verified. The efficacy of CM326 in patients with eosinophilic CRSwNP (TEC ≥55/high power field [HPF]), as well as noneosinophilic CRSwNP (TEC <55/HPF) will be testified.

Trial registration: NCT05324137.