In individuals having severe eosinophilic asthma and concomitant chronic rhinosinusitis and nasal polyposis, mepolizumab leads to improvement in sino-nasal and asthma symptoms and minimizes polyp growth. 

This prospective, observational, real-life study was carried to determine the efficacy of mepolizumab (anti-interleukin-5 monoclonal antibody) on sino-nasal symptoms, polyp growth, and asthma control in asthma patients having chronic rhinosinusitis and nasal polyposis.

The 12-month study incorporated 44 asthma subjects suffering from chronic rhinosinusitis and nasal polyposis in real life. Participants were treated with subcutaneously administered mepolizumab (100 mg every four weeks) for one year. The endpoints were evaluated before (T0), after six (T6) and 12 months (T12) of therapy: Asthma control test (ACT), forced expiratory volume at 1 sec (% FEV1), Total Endoscopic Nasal Polyp Score (TENPS), and sino/nasal outcome test (SNOT-22).

Also, blood eosinophil count, prednisone consumption, and fractional exhaled nitric oxide (FENO) were estimated. In a subgroup of participants, the nasal cytology was conducted before, after six, and 12 months of mepolizumab therapy.

There was a substantial decline of SNOTT-22 and TENPS from the baseline. The nasal cytology findings indicated a considerable decrease of eosinophil percentage after mepolizumab treatment, as  shown in Table 1: 

Remarkable improvements of % FEV1 and ACT, and a decline in blood eosinophils and mean prednisone consumption were also witnessed. For FENO, there was no vital decreasing trend.

Mepolizumab used in a real-life setting to treat severe eosinophilic asthma improves sino-nasal and asthma outcomes, minimizes polyp growth, and exerts a steroid-sparing effect in patients with concomitant chronic rhinosinusitis and nasal polyposis.