Mepolizumab Significantly Improves CRSwNP in Real-World Analysis

Amy Edgecomb, PharmD, BS, MPH

Credit: University of North Carolina at Chapel Hill

A real-world analysis showed patients with chronic rhinosinusitis with nasal polyps (CRSwNP) had substantial symptom improvement on mepolizumab.¹

This retrospective chart review using a pre and post-study design, presented at the 2025 American Academy of Allergy, Asthma, & Immunology (AAAAI) in San Diego from February 28 – March 3, offered insights into the effectiveness of mepolizumab 100 mg for CRSwNP.

Mepolizumab has previously been linked to significant improvements in endoscopic nasal polyps.² SYNPASE, a randomized, double-blind, placebo-controlled, parallel-group phase 3 trial conducted across 11 countries, demonstrated mepolizumab 100 mg significantly improves the total endoscopic nasal polyp score from baseline to week 52 in patients with chronic rhinosinusitis compared with placebo (-0.73; 95% confidence interval [CI], -1.11 to 0.34; P < .0001). Although clinical trials have demonstrated the efficacy of mepolizumab on CRSwNP, limited data exist on the effectiveness of mepolizumab in real-world US patients

A team of allergists/immunologists (n = 38) and otolaryngologists (n = 26), led by Amy Edgecomb, PharmD, BS, MPH, the associate director of the US Value Evidence and Outcomes at GlaxoSmithKline, PA, examined charts for adult patients with CRSwNP treated with mepolizumab (100 mg) between July 29, 2021 and April 30, 2023.¹ Patients included in the study had ≥ 12 months of medical records and ≥ 1 Sino-Nasal Outcome Test-22 (SNOT 22) patient-reported assessment before and after initiating mepolizumab.

The sample included 150 patients (43% females, 76% White participants), with a mean age of 44 years. Patients had a median follow-up of 20.6 months. Common comorbidities included allergic rhinitis (55%) and asthma (51%) which was either mild/moderate (87%) or severe (13%).

Approximately 15% of patients discontinued mepolizumab after receiving symptom control or improvement on this drug (77%). After taking mepolizumab, mean SNOT-22 scores significantly improved from 61 to 28 (mean difference, -32; 95% CI, -35 to 29; P < .001). Moreover, 89% of patients had clinically significant improvement in the SNOT-22 score after taking mepolizumab. The mean difference based on the lowest score post-mepolizumab was ≥ 8.95.

Additionally, oral corticosteroid use significantly dropped post-mepolizumab, reducing from 0.6 per patient per year before mepolizumab to 0.3 after mepolizumab (rate ratio, 0.46; 95% CI, 0.30 – 0.72; P < .001). Oral corticosteroid bursts (1 vs 0; P < .001) and mean cumulative dose (766 mg vs 256 mg; P < .001) significantly reduced per year from pre-mepolizumab to post- mepolizumab. Surgical intervention rates per person per year numerically improved from pre-mepolizumab (0.2 vs 0.1).

“In real-world patients with CRSwNP, mepolizumab substantially improved SNOT-22 scores and treatment burden,” investigators concluded.

References

1. Edgecomb, A, Silver, J, Hwee, J, et al. Mepolizumab Improves Patient-Reported Outcomes and Reduces Treatment Burden in Patients with Chronic Rhinosinusitis With Nasal Polyps: A Real-World Chart Review Study. Journal of Allergy and Clinical Immunology, Volume 155, Issue 2, AB448.

2. Alicea, J. Add-On Mepolizumab Promising Option for Chronic Rhinosinusitis with Nasal Polyps. HCPLive. April 20, 2024. https://www.hcplive.com/view/add-on-mepolizumab-promising-option-chronic-rhinosinusitis-nasal-polyps. Accessed February 24, 2025.