When hypereosinophilia occurs during dupilumab therapy: evidence-based strategies for clinical management in respiratory indications

INTRODUCTION: Dupilumab is a monoclonal antibody which selectively targets T2 inflammation by binding the IL-4 and 13 receptor and blocking its contribution to the immune activation. Clinical trials and real-life studies on severe asthma and nasal polyps patients have reported blood eosinophils fluctuation over the treatment course. AREAS COVERED: In the present narrative review the authors aim to provide a practical perspective on the recent evidence related to hypereosinophilia occurring during dupilumab therapy in respiratory indications, its underlying mechanisms, frequency, and clinical relevance, and to critically revise the currently proposed approaches to its management. Eosinophils increase is in most cases transient, spontaneously resolving, without any clinical relevance and no impact on efficacy. In fact, dupilumab safety profile is overall comparable with the other monoclonal antibody of the same drug class. EXPERT OPINION: Blood eosinophil count itself should not preclude dupilumab prescription, neither lead to dupilumab discontinuation, especially in the presence of ascertained drug efficacy and in the absence of signs suggesting a eosinophils-related complication. However, an extensive diagnostic work-up and regular follow-up monitoring is indicated, especially in patients with increased baseline eosinophils and coexisting nasal polyps and asthma.