Benralizumab effect on severe chronic rhinosinusitis with nasal polyps (CRSwNP): A randomized double-blind placebo-controlled trial

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) can be a severe and debilitating disease associated with significant morbidity, loss of smell, sinus pressure and asthma exacerbations. Eosinophils play a role in the majority (85%) of patients. Benralizumab, an afucosylated monoclonal antibody directed against the IL-5 receptor, has powerful apoptotic effects on eosinophils. Objective: We sought to investigate the therapeutic benefit of inhibiting the IL-5 receptor using benralizumab to treat severe rhinosinusitis with nasal polyps. Methods: Patients with severe NP (defined by endoscopic grade 5 or more out of 8) with elevated eosinophils and a history of previous surgical or endoscopic polypectomy met entry criteria and were randomized in a double-blind fashion to receive 30 mg benralizumab SC or placebo. Endoscopic NP score was assessed at baseline and at treatment week 20. CT scan, SNOT-22 survey and UPSIT smell test score changes were also evaluated. Results: Thirty-three patients were screened, and twenty-four (n = 24) were enrolled in the study. Compared with baseline, benralizumab significantly improved NP score (−0.9 ± 0.2, P = 0.004) whereas placebo did not (−0.3 ± 0.3, P = 0.166). Benralizumab induced polyp size reduction compared with placebo did not reach statistical significance (P = 0.103). Five of 12 benralizumab-treated patients (42%) had improvements in all major outcomes (polyp score, CT, SNOT-22 and smell test) versus 2 out of 12 placebo (17%). The ratio of blood eosinophil count to allergen skin test positivity correlated with polyp reduction. Conclusion: Benralizumab was well-tolerated and compared with baseline achieved a statistically significant reduction in nasal polyp size, sinus occupancy, symptoms and improved sensation of smell for most patients (83%).