Efficacy of dupilumab in patient with hypereosinophilic syndrome and asthma non-responsive to anti-IL5 and anti-IL5r treatment.

<bold>Background:</bold> Hypereosinophilic syndrome (HES) is a heterogeneous group of disorders characterized by persistent eosinophilia and associated organ damage. Comorbid asthma in HES patients poses a therapeutic challenge, especially in cases resistant to standard eosinophil-lowering therapies. This case report describes the effective management of a 31-year-old patient with HES and asthma using dupilumab after unsuccessful treatments with mepolizumab and benralizumab. Case Presentation: A 31-year-old individual with a lifelong history of severe asthma and HES, presented with uncontrolled symptoms and 4 yearly exacerbations despite previous treatment with high-dose inhaled corticosteroids and two different biologics over the last 5 years: initially with mepolizumab (300-700mg q4w), which was withdrawn after 3 years due to diminishing efficacy and benralizumab (30mg q4w), which was ceased after 6 months due to lack of response. The patient exhibited poor asthma control and recurrent exacerbations, despite low blood eosinophil levels. Following a comprehensive evaluation, treatment with dupilumab was initiated. <bold>Results:</bold> Remarkable improvement was observed within first 2 weeks of starting dupilumab. At a 6-month checkpoint we observed a significant improvement in both ACQ (from 3.5 to 0.9) and AQLQ (2.3 to 5.9) scores. The patient did not experience any exacerbations and managed to reduce daily dose of oral corticosteroids from 25mg to 10mg of prednisone. No significant adverse effects or increase in eosinophil counts were noted during the treatment course.