IL5 and nasal cavity polyp: <h4>Introduction</h4>This meta-analysis aimed to evaluate the safety and efficacy of anti-IL-5 monoclonal antibody (anti-IL-5 mAb) as a second-line therapy for chronic rhinosinusitis with nasal polyps (CRSwNP).<h4>Materials and methods</h4>Four databases (PubMed, Web of Science, Embase and Cochrane Library) were searched from the establishment of the databases to September 15, 2025, for randomized controlled trials (RCTs) comparing anti-IL-5 mAb versus placebo in the treatment of CRSwNP.