Efficacy and safety of mepolizumab in the treatment of CRSwNP in the real-life setting: a review of the literature

Purpose: The anti-IL-5 agent mepolizumab has been recently approved for the treatment of severe and treatment-resistant forms of type 2 chronic rhinosinusitis with nasal polyps. However, a review summarizing the results of real-life studies and comparing them to results from phase III clinical trials, SYNAPSE and MERIT, is still lacking. Methods: A search of all real-life studies published from 2019 to 2025 was conducted. Patients characteristics at baseline and 6 and 12 months after starting mepolizumab were extracted and compared to those from phase III trials: age, sex, comorbid eosinophilic asthma, and nonsteroidal antiinflammatory drugs-exacerbated respiratory disease (N-ERD), atopy, previous endoscopic sinus surgery (ESS), blood eosinophils count (BEC), NPS, sense of smell, SNOT-22, Lund-Mackay score, adverse events (AEs), and response to treatment. Results: 13 papers were included, encompassing an overall number of 608 patients. A higher rate of comorbid asthma and N-ERD, but a lower rate of previous ESS, was found in the real-life cohort. Despite higher BEC, sinonasal symptom scores were generally lower in the real-life population. Nonetheless, mepolizumab led to improvements in mean BEC, SNOT-22, NPS, sniffin’ sticks identification test, and loss of smell VAS in a real-life setting. Comorbid N-ERD was associated with better NPS outcomes but worse SNOT-22 scores and olfactory function, while no significant differences were observed regarding asthma. AEs were reported by 14.0% of patients, with 1.5% discontinuing mepolizumab, while non-responders were 7.9%. Conclusions: Mepolizumab was safe and effective, even in a real-life scenario, with results similar to those observed in phase III clinical trials.