text: On 12 December 2017, the FDA approved mepolizumab, the first drug therapy specifically indicated for the treatment of eosinophilic granulomatosis with polyangiitis. Patients taking mepolizumab experienced a "significant improvement" in their symptoms. Mepolizumab is a monoclonal antibody that targets interleukin-5, a major factor in eosinophil survival.
  In addition to mepolizumab, a number of emerging targeted biotherapies—including the anti-IgE monoclonal antibody omalizumab, immunomodulation with Interferon-α, and B cell therapy with rituximab—may lead to increasingly personalized treatment regimens for future EGPA patients. A review of EGPA treatments conducted in 2020 proposes integrating targeted biotherapies into EGPA management plans following failure of treatment with corticosteroids.
  History
  Eosinophilic granulomatosis with polyangiitis was first described by pathologists Jacob Churg (1910–2005) and Lotte Strauss (1913–1985) at Mount Sinai Hospital in New York City in 1951, using the term "allergic granulomatosis" to describe it. They reported "fever...hypereosinophilia, symptoms of cardiac failure, renal damage, and peripheral neuropathy, resulting from vascular embarrassment in various systems of organs" in a series of 13 patients with necrotizing vasculitis previously diagnosed as "periarteritis nodosa", accompanied by hypereosinophilia and severe asthma. Churg and Strauss noted three features which distinguished their patients from other patients with periarteritis nodosa but without asthma: necrotizing vasculitis, tissue eosinophilia, and extravascular granuloma. As a result, they proposed that these cases were evident of a different disease entity, which they referred to as "allergic granulomatosis and angiitis".