Improved Sense of Smell Achieved With Biologics for CRS With Nasal Polyps, Asthma

Patients with comorbid chronic rhinosinusitis (CRS) with nasal polyps and severe asthma reported significant improvement in their sense of smell when treated with the biologics omalizumab, mepolizumab, reslizumab, or benralizumab, with no significant differences observed between the treatment groups.

Biologic use for the treatment of chronic rhinosinusitis with nasal polyps (CRSwNP) and severe asthma was associated with significant improvement in olfactory function, according to study findings published in Journal of Investigational Allergology and Clinical Immunology.

With up to 80% of patients with CRSwNP estimated to experience olfactory dysfunction, the presence of comorbidities, such as asthma and/or nonsteroidal anti-inflammatory drug–exacerbated respiratory disease (NERD), was cited by the researchers of the present study to worsen disease severity and increase treatment-related costs.

“The sense of smell is a constant source of valuable information for humans, enabling them to detect harmful odors as well as enjoy pleasurable experiences…additionally, an impaired sense of smell is related to low quality of life, with higher rates of depression and severity of disease,” said the study authors.

“Loss of smell is more frequent in the type 2 endotype of CRSwNP and is associated with respiratory diseases such as asthma, bronchiectasis, and NERD," they added.

Specific biologic therapies targeting type 2 inflammation have been developed, they added, with anti–immunoglubin E (IgE) (omalizumab), anti–interleukin (IL)-5 (mepolizumab, reslizumab, benralizumab), and anti–L-4/IL-13 (dupilumab) monoclonal antibodies having demonstrated significant improvement of sinonasal symptoms, including olfactory function.

The researchers conducted a multicenter, noninterventional, retrospective, observational study to determine whether, in real-life conditions, biological treatments prescribed for severe asthma can improve olfaction in patients with CRSwNP. Additional analyses were performed to investigate differences between monoclonal antibodies based on their respective targets (anti-IgE, anti–IL-5, and anti–IL-4/IL-13), and compare smell improvement in NERD and non-NERD subgroups.

The study included 206 patients with severe asthma and CRSwNP (mean [SD] age, 56 [13] years; 56.8% female) undergoing biological treatment, including omalizumab (n = 81), mepolizumab (n = 65), benralizumab (n = 46), or reslizumab (n = 14), with the dupilumab subgroup excluded due to its small size.

Outcomes assessed were partial improvement (change from anosmia to hyposmia), total improvement (change from anosmia or hyposmia to normosmia), and no improvement (subjects with no improvement or who experienced a deterioration in their olfaction).

Results showed that total or partial improvement in loss of smell was achieved after treatment with all monoclonal antibodies, with no differences between groups: omalizumab (35.8%), mepolizumab (35.4%), reslizumab (35.7%), and benralizumab (39.1%). Improvement of olfaction was more likely to be reported in patients with atopy, greater use of short-course systemic corticosteroids, and larger polyp size.

About 61% to 64% of patients reported no improvement, with no statistical differences found between biologic treatments. The proportion of patients experiencing smell improvement was similar between the NERD (37%) and non-NERD (35.7%) groups.

“This is the first study to compare real-life improvement in sense of smell among patients undergoing long-term treatment with omalizumab, mepolizumab, reslizumab, or benralizumab for severe asthma and associated CRSwNP,” concluded the study authors. “Approximately 4 out of 10 patients reported a subjective improvement in sense of smell (with nonsignificant differences between biologic drugs).”


Barroso B, Valverde-Monge M, Alobid I, et al. Smell improvement by anti-IgE and anti-IL 5 biologics in patients with CRSwNP and severe asthma. A real life study. J Investig Allergol Clin Immunol. Published online April 12, 2022. doi:10.18176/jiaci.0812