STEROID SPARING STRATEGY WITH DUAL BIOLOGICS IN TREATING HYPEREOSINOPHILLIC SYNDROME

Abstract

<h3>Introduction</h3> Hypereosinophilic Syndrome (HES) is a multisystem disorder characterized by peripheral blood eosinophilia and organ impairment due to eosinophil infiltration. Treatment primarily consists of reducing eosinophil levels via a variety of modalities, including corticosteroids, which carry significant side effects. Different strategies have been developed to reduce the dosage of chronic steroids that a patient receives. <h3>Case Description</h3> A 62 year-old female patient has been followed in our Allergy and Immunology clinic for 17 years for her Lymphocytic hypereosinophillic syndrome. Her treatment has been changed throughout the years to control symptoms and eosinophil level. For the past few years, she has been stabilized on a regimen of mepolizumab 300 mg subcutaneous q6 weeks, daily cyclosporine, as well as prednisone 7.5 mg daily. Prednisone tapering has been attempted multiple times in the past without success. In March of 2022, duplilumab was added after insurance approval. Dupilumab, which is FDA approved for eosinophilic esophagitis as well as eosinophilic asthma, was chosen as additional therapy blocking the IL-4/IL-13 pathway, unique to mepolizumab's IL-5 pathway. She was started on a 600mg loading dose and 300mg q2weeks. Within 4 weeks, her prednisone was successfully tapered to 5mg, the lowest dose in the last 17 years, and further taper is in process. <h3>Discussion</h3> Dual biologic therapy with both dupilumab and mepolizumab is a potential steroid sparing strategy for patients with refractory hypereosinophilic syndrome. Further studies to validate the efficacy and identify ideal dosing combination of such dual biologic therapy in sparing steroids is indicated.