Allergic Fungal Rhinosinusitis: The Role and Expectations of Biologics

Allergic fungal rhinosinusitis (AFRS) is a noninvasive subtype of chronic rhinosinusitis with nasal polyps (CRSwNP) that usually develops in immunocompetent atopic individuals and is more common in geographic regions characterized by warm temperatures and high humidity, conducive to higher environmental fungal presence. Allergic fungal rhinosinusitis usually presents with unique computed tomography findings and significant polyp burden, yet patients often report minimal sinus symptoms. Patients with AFRS often have extremely elevated serum total and fungal-specific IgE levels. Treatment almost always requires surgery, in which adjuvant medical therapy is critical to success. However, until recently the choice of adjuvant therapy has consisted primarily of either oral and/or topical steroids. Although oral corticosteroids decrease recurrence after surgery, data for the effectiveness of other adjunctive pharmacologic agents, including topical and oral antifungal agents and immunotherapy, have remained unclear and hence are not recommended in recent guidelines including the International Consensus of Allergy and Rhinology. Three biologics, omalizumab, dupilumab, and mepolizumab, have recently been approved for treating CRSwNP in general, but clinical trials to date with these biologics did not involve AFRS patients. Recently published case reports and smaller prospective studies have shown good efficacy of these biologics on the AFRS subgroup of patients. This article provides an overview of the understanding of the pathophysiology of AFRS, implications of this understanding on the possible role of biologics, and clinical reports on the use of biologics in treating AFRS. Because biologics are indicated for treating CRSwNP, follow up real-world evidence studies are needed for AFRS.