Can anti-IL-5 biologics be used to treat severe chronic rhinosinusitis?
Chronic rhinosinusitis (CRS) is a long-term inflammation of the nasal and sinus linings that can cause nasal blockage, facial pressure, and loss of smell. In many cases, especially when nasal polyps are present, the inflammation is driven by a type 2 immune response involving high levels of interleukin-5 (IL-5) and eosinophils. Anti-IL-5 biologics are medications that block IL-5 or its receptor, reducing eosinophil activity. For people with severe CRS with nasal polyps (CRSwNP) that does not improve with standard treatments like nasal sprays or surgery, anti-IL-5 biologics offer a targeted option. Clinical trials and reviews show they can improve symptoms, shrink polyps, and reduce the need for corticosteroids and surgery.
What the research says
A 2021 Cochrane systematic review evaluated biologics for chronic rhinosinusitis and found that anti-IL-5 antibodies (mepolizumab, reslizumab) and anti-IL-5 receptor antibodies (benralizumab) improve disease-specific quality of life and reduce nasal polyp size compared to placebo 7. The review included randomized controlled trials with at least three months of follow-up. A 2025 review of biologic therapies for severe asthma notes that mepolizumab and benralizumab are also approved for chronic rhinosinusitis with nasal polyps (CRSwNP), the most common asthma comorbidity 8. Another 2022 review explains that IL-5 is critical for eosinophil differentiation, migration, and survival, and that elevated IL-5 and eosinophils are linked to nasal polyp formation and recurrence after surgery 9. A systematic review of anti-IL-5 and anti-IL-5Rα biologics for eosinophilic diseases confirms their use in CRSwNP, showing reductions in nasal polyp score, need for systemic corticosteroids, and need for sinus surgery 5. Overall, the evidence supports anti-IL-5 biologics as effective add-on treatments for severe CRSwNP, though they are not typically used for CRS without nasal polyps.
What to ask your doctor
- Do my symptoms and nasal polyp status suggest I have type 2 inflammation that might respond to an anti-IL-5 biologic?
- Have I tried standard treatments (nasal corticosteroids, saline rinses, antibiotics, sinus surgery) without enough improvement?
- Which anti-IL-5 biologic (mepolizumab, reslizumab, or benralizumab) might be appropriate for me, and what are the potential side effects?
- How would we monitor treatment response — for example, with symptom scores, nasal endoscopy, or smell tests?
- Are there any other biologics (like dupilumab) that might be a better option for my specific condition?
This question is drawn from common patient questions about ENT (Otolaryngology) and answered using cited medical research. We do not provide individualized advice.