Eosinophilic granulomatosis with polyangiitis: overcoming diagnostic obstacles and exploring pharmacotherapeutic approaches

Eosinophilic granulomatosis with polyangiitis (EGPA) is an uncommon form of necrotizing vasculitis that affects the respiratory system and other organs, characterized by asthma, eosinophilia, and multiple organ involvement that complicates the diagnosis and treatment. There are no definitive open-label clinical data on the diagnosis or treatment of EGPA to guide clinicians. The diverse presentation of the disease, distinct from other eosinophilic disorders; the presence of competing conditions such as allergy and asthma, which also have potential biomarkers; lack of a definitive test to confirm diagnosis; difficulties in obtaining endoscopic biopsies for histologic confirmation, etc., are significant barriers to early detection. Even with recent advances in imaging, immunological approaches, and molecular testing to determine the disease’s identity and characteristics, clinicians still misdiagnose or delay treatment, sometimes leading to life-threatening and irreversible complications. Though EGPA is pharmacotherapeutically controlled with glucocorticoids, it has typically included the use of cytotoxic agents such as cyclophosphamide for induction in cases of severity. Recently, several clinical trials have examined targeted biologic treatments (such as mepolizumab, benralizumab, and omalizumab) and demonstrated that these medications can reduce exacerbations, decrease the need for glucocorticoids, and improve asthma control. New drugs such as dupilumab and new anti-IL-5/IL-5R monoclonal antibodies are being studied in phase II and phase III trials, and these drugs may provide additional avenues for refractory disease. Treatment will be organized based on individualization of treatment strategy, depending on disease severity, organ involvement, and biomarker profile. Vertical investment in multicenter longitudinal studies is necessary to formulate therapeutic algorithms and evaluate new targets.