Background: Retrospective data are limited on the effectiveness of mepolizumab treatment that is reflective of real-world practice in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Objective: We evaluated changes in administration of nasal polyp (NP)-related oral corticosteroids (OCS) and other treatments, exacerbations, sinus surgeries, NP-related health care resource utilization, and costs before and after mepolizumab initiation in patients with CRSwNP. Methods: Retrospective cohort study using data from the Komodo Research database included adults with CRSwNP, without severe asthma, initiating mepolizumab therapy on or after July 29, 2021 (index date), with 12 months of continuous health care enrollment before index and ≥6 months after index. Treatment with reslizumab, benralizumab, or tezepelumab during the study period was excluded. Outcomes were compared pre- versus post-mepolizumab initiation for the overall population and on-label subgroup analysis. Results: Mean number of NP-related OCS dispensings per patient per year (PPPY) (0.5 after vs 1.2 before therapy initiation), total mean OCS dose (119.1 vs 309.9 mg), mean daily OCS dose per period (0.3 vs 0.8 mg), and mean number of OCS bursts (0.3 vs 0.7) were significantly lower after versus before initiation, respectively (all P < .001). Numbers of patients requiring NP-related treatments significantly decreased (75.0% post vs 86.7% pre, P < .001). Mean number of NP-related exacerbations experienced by patients significantly reduced (1.6 PPPY pre vs 0.3 PPPY post). Mean number of sinus surgeries significantly reduced after initiation (annual rate ratio [95% confidence interval] 0.23 [0.13, 0.40], P < .001), as did rate of otolaryngologist visits PPPY, excluding mepolizumab administration visits (rate ratio 0.52 [95% confidence interval 0.43, 0.63], P < .001). Conclusion: In this first retrospective mepolizumab study for patients with CRSwNP without severe asthma, improvements in all outcomes were observed after mepolizumab initiation.

Background: Trial data demonstrate that mepolizumab, a humanized anti-interleukin 5 monoclonal antibody, is effective for patients with severe asthma and comorbid chronic rhinosinusitis (CRS) with nasal polyps. This real-world, retrospective cohort study investigated mepolizumab for US patients with severe asthma and CRS with/without sinus surgery. Methods: IQVIA PharMetrics Plus claims data from baseline and follow-up (12 months before and after mepolizumab initiation) were used to analyze three patient cohorts: cohort 1 (severe asthma only); cohort 2 (severe asthma + comorbid CRS without sinus surgery); and cohort 3 (severe asthma+comorbid CRS+sinus surgery), allowing for cross-cohort comparisons. Results: The analysis included 495, 370, and 85 patients in cohort 1, cohort 2, and cohort 3, respectively. Systemic and oral corticosteroid use was lower for all cohorts after mepolizumab initiation. In cohort 3, asthma rescue inhaler and antibiotic use were lower during follow-up than baseline. Asthma exacerbations were reduced by 28% to 44% comparing follow-up versus baseline, with the largest reduction in cohort 3 (ratio of incidence rate ratio [RR] vs cohort 1: 0.76; p = 0.036). Reductions in oral corticosteroid claims were greater following mepolizumab initiation for cohort 3 versus cohort 1 (RR, 0.72; p = 0.011) and cohort 2 (RR, 0.70; p < 0.01). In cohorts 1 through 3, outpatient and emergency department visits were reduced by 1 to 2 and 0.4 to 0.6 visits annually, asthma-related and asthma exacerbation-related total costs were reduced by $387 to $2580 USD, and medical costs were reduced by $383 to $2438 USD during follow-up. Conclusions: Consistent with trial data, mepolizumab use in real-world practice shows benefits across comorbid patient cohorts with more a pronounced impact in those with severe asthma+comorbid CRS + sinus surgery.