Efficacy of mepolizumab treatment in oral corticosteroid-dependent severe eosinophilic asthma patients with chronic rhinosinusitis with nasal polyps: single center, real life study

Background/aim: Oral corticosteroid (OCS)-dependent severe eosinophilic asthma with chronic rhinosinusitis with nasal polyps (SEA-CRSwNP) would be a suitable phenotype for mepolizumab treatment. This study evaluated the short-term efficacy of mepolizumab treatment in OCS-dependent SEA-CRSwNP. Materials and methods: Baseline and 24th week results [daily OCS doses, asthma exacerbation frequency, asthma control test (ACT) scores, blood eosinophil levels, FEV1 values, and numerical analog scale (NAS) of CRSwNP symptoms] of patients who were treated for at least 24 weeks with mepolizumab were retrospectively evaluated and compared. Results: A total of 16 patients were enrolled in the study. Mepolizumab was discontinued in one patient due to side effects. The daily OCS dosage was reduced from baseline in all patients, and at week 24 OCS was discontinued in 40% of the patients (baseline mean steroid dose: 9.2 +/- 5.2 mg, 24th week: 1.3 +/- 1.4 mg; P < 0.001). The number of asthma exacerbations within 24 weeks significantly decreased after beginning mepolizumab treatment (2.1 +/- 2.7 vs. 0.07 +/- 0.26; P = 0.012), and a significant increase in ACT scores (baseline mean ACT: 18 +/- 5.7; 24th week mean ACT: 23.3 +/- 3; P = 0.006) was observed despite the decrease in daily OCS dosages. There was no significant difference in FEV 1 values between baseline and week 24. Evaluation of the general symptoms of CRSwNP, as per NAS, revealed that the baseline mean NAS was 5.6 +/- 4.4, and the 24th week mean NAS was 3.2 +/- 3.2 (P = 0.021). Conclusion: This is the first real-life study evaluating the short-term efficacy of mepolizumab treatment on OCS-dependent SEACRSwNP. This study demonstrates that mepolizumab is an effective and safe biologic for the treatment of this severe asthma subphenotype.