A recent multinational trial investigated the efficacy of mepolizumab in reducing the need for surgery to treat recurring severe nasal polyps.
Nasal polyps are non-cancerous outgrowths of the mucosa in the nasal passages that usually form at the opening of the sinus cavities. Polyps are a reflection of inflammation of the nasal membrane caused by the prominent presence of local inflammatory cells called eosinophils. Large polyps can cause chronic nasal obstruction and congestion, which can affect a patient’s quality of life. Treatment for nasal polyps includes daily use of corticosteroid nasal sprays, long-term antibiotics, and surgery. Recurrent surgery is very common.
A novel treatment for nasal polyps, an antibody targeting the inflammatory cells, is currently under investigation. Previous studies have shown that this antibody can reduce the size of nasal polyps. Researchers at the Upper Airways Research Laboratory at the Ghent University Hospital aimed to confirm these results with a study including a larger population. Their primary endpoint was the number of patients that no longer required surgery at the end of the treatment period. The results of this trial were published in the Journal of Allergy and Clinical Immunology.
In this multicenter, double-blinded trial, patients from Belgium, the Netherlands, and the United Kingdom were randomized to receive either a placebo (53 patients) or mepolizumab (54 patients). The patients were required to use corticosteroid nasal sprays regularly for three months preceding the study period. Ten to 14 days prior to the study period (run-in period), the researchers had the patients use fluticasone nasal spray at a dose of two sprays into each nostril every morning. This may present as a limitation to the study since some patients may not respond to that particular corticosteroid and may have experienced worse symptoms than with their usual nasal spray. Either mepolizumab or a placebo was then injected intravenously every four weeks for six months, for a total of six doses. The same intranasal corticosteroid spray as the run-in period was continued throughout the six-month study period.
Mepolizumab Reduced the Need for Surgery
At the end of the study period, significantly more patients no longer met the required criteria for surgery. A significant improvement in nasal polyp severity score was documented in the mepolizumab group. Improvement in the total endoscopic nasal polyp score was achieved in the patients receiving mepolizumab when compared with placebo. Finally, individual symptom scores (including mucus in the throat, nasal obstruction, and loss of smell) were significantly improved with mepolizumab. The most common side effects reported in this study included headaches and nasopharyngitis, however, the rates of each of these side effects were similar in both treatment groups.
The results of this larger study confirmed prior studies on the efficacy of mepolizumab. This injectable treatment has potential to reduce the need for surgery in patients with severe nasal polyps and improve quality of life. Studies with a longer treatment period, different dosing, and a complete analysis of the side effects are required to further confirm the results of this study.
Written by Jessica Caporuscio, PharmD
(1) Bachert C, Sousa AR, Lund VJ, et al. Reduced need for surgery in severe nasal polyposis with mepolizumab: Randomized trial. J Allergy Clin Immunol. 2017.
(2) Fried, MP. Nasal Polyps. Merck Manual Consumer Version. http://www.merckmanuals.com/en-ca/home/ear,-nose,-and-throat-disorders/nose-and-sinus-disorders/nasal-polyps