Mepolizumab reduces the need for surgery in patients with chronic rhinosinusitis with nasal polyps

Background: For patients with chronic rhinosinusitis with nasal polyps (CRSwNP), endoscopic sinus surgery (ESS) can be associated with high recurrence rates despite intranasal corticosteroids (as part of standard of care [SoC]). We assessed the impact of mepolizumab, a humanized anti-interleukin-5 antibody, on the need for repeat ESS in patients with CRSwNP. Methods: SYNAPSE, a randomized, double-blind, placebo-controlled, multicenter study, enrolled patients with CRSwNP uncontrolled with SoC. All patients had ≥1 ESS in the past 10 years and were eligible for repeat ESS. Patients received 4-weekly subcutaneous (SC) mepolizumab 100 mg or placebo, plus SoC, for 52 Weeks. We assessed the proportion of patients with a need for ESS (visual analog scale overall symptom score >7; endoscopic bilateral NP score ≥5), time to inclusion on a waiting list for ESS (Kaplan–Meier [KM] estimate), and the proportion of patients included on a waiting list, by Week 52. Results: Data from 407 patients (placebo n=201; mepolizumab n=206) were analyzed. Mean (SD) duration of CRSwNP was 11.4 (8.4) years; 218 (54%) patients had ≥2 ESS in the past 10 years. After 52 weeks, more patients using mepolizumab vs placebo were identified as not needing ESS (72% vs 51%, respectively; odds ratio [95% confidence interval] 2.46 [1.59, 3.79]; P<0.001). KM estimates indicated a ~50% lower risk of inclusion on a waiting list for ESS with mepolizumab than placebo. Up to Week 52, 16% vs 30% of patients using mepolizumab vs placebo were due for ESS on a waiting list. Conclusions: Mepolizumab 100 mg SC reduces the need for repeat surgery compared with placebo for patients with recurrent CRSwNP despite SoC therapy.