Eosinophilia and Adverse Effects of Dupilumab for Respiratory Indications: A Real-World Setting

Background: Dupilumab has been used with significant benefit in the treatment of asthma and chronic rhinosinusitis with nasal polyps (CRSwNP). Phase 3 clinical trials have demonstrated transient eosinophilia and rare eosinophil-related and other adverse effects. Objective: To characterize dupilumab-associated eosinophilia (absolute eosinophil count ≥1.5 × 10³/μL within 36 weeks of dupilumab initiation) and adverse effects associated in real-world patients with asthma and CRSwNP in the United States. Methods: Retrospective chart review of 251 patients receiving dupilumab for asthma and/or CRSwNP seen at a single institution. Results: Among the 142 patients who had absolute eosinophil counts checked before and after treatment, 16 (11.3%) had posttreatment eosinophilia, including 11 (7.7%) who had new eosinophilia on dupilumab initiation. Thirteen patients with posttreatment eosinophilia remained on dupilumab, 10 of whom had resolution of eosinophilia. Eosinophil-related adverse effects were rare, and cases of eosinophilic granulomatous polyangiitis were limited to one patient with eosinophilia and one patient with normal eosinophil levels who was receiving systemic corticosteroids. Other adverse effects included arthralgias (13 of 251; 5.2%), rash (8 of 251; 3.2%), and conjunctivitis (7 of 251; 2.8%). All patients with pretreatment eosinophilia and most patients with posttreatment eosinophilia received significant treatment benefit for the respiratory disease with dupilumab. Conclusions: Whereas dupilumab-associated eosinophilia is seen in a subset of patients, persistent eosinophilia or eosinophil-related adverse effects are rare. Furthermore, treatment benefit with dupilumab despite eosinophilia supports its continued use in both asthma and CRSwNP.