Dexpramipexole depletes blood and tissue eosinophils in nasal polyps with no change in polyp size

Single cell RNA sequencing of human eosinophils from nasal polyps reveals eosinophil heterogeneity in chronic rhinosinusitis tissue

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized by type 2 inflammation in the United States, but the actual roles that eosinophils play in CRSwNP remain largely unclear.

OBJECTIVE

To reveal the roles and heterogeneity of eosinophils in nasal polyp (NP) tissue, we performed single cell RNA sequencing (scRNA-Seq) analysis of NP tissue.

METHODS

Sinonasal tissues (NP and control sinus tissue) and patient matched peripheral blood (PB) samples were obtained from 5 control patients and 5 patients with CRSwNP. Eosinophils were enriched before processing for scRNA-Seq. The gene expression profiles in eosinophils were determined by microwell-based scRNA-Seq technology (BD Rhapsody platform). We predicted the overall function of NP eosinophils by Gene Ontology (geneontology.org) enrichment and pathway analyses and confirmed expression of selected genes by flow cytometry.

RESULTS

After filtering out contaminating cells, we detected 5,542 eosinophils from control PB, 3,883 eosinophils from CRSwNP PB, 101 eosinophils from control sinus tissues (not included in further analyses), and 9,727 eosinophils from NPs by scRNA-Seq. We found that 204 genes were downregulated and 354 genes upregulated in NP eosinophils compared to all PB eosinophils (>1.5-fold, Padj < .05). Upregulated genes in NP eosinophils were associated with activation, cytokine-mediated signaling, growth factor activity, NF-κB signaling, and antiapoptotic molecules. NP eosinophils displayed 4 clusters revealing potential heterogeneity of eosinophils in NP tissue.

CONCLUSIONS

Elevated eosinophils in NP tissue appear to exist in several subtypes that may play important pathogenic roles in CRSwNP, in part by controlling inflammation and hyperproliferation of other cells.

Predictors of persistent disease in biologic treated type 2 diffuse/eosinophilic chronic rhinosinusitis undergoing surgery

BACKGROUND

Biologic therapy targeting type 2 chronic rhinosinusitis with nasal polyps (CRSwNP) has greatly improved disease control but nonresponders exist in a proportion of patients in phase 3 trials and clinical practice. This study explores the serum and histologic changes in biologic treated CRSwNP that predict disease control.

METHODS

A cross-sectional study was performed of patients with CRSwNP on biologics for their asthma, who underwent endoscopic sinus surgery while on biologic therapy. At the 6-month postoperative assessment, patients with poorly controlled CRSwNP while on biologic therapy were compared to patients who were controlled. Blood and mucosal samples taken at the time of surgery 6 months prior were assessed to predict disease control.

RESULTS

A total of 37 patients were included (age 47.8 ± 12.4 years, 43.2% female). Those with poorly controlled disease had reduced tissue eosinophils (% >100 cells/high-powered field: 8.3% vs. 50.0%, p < 0.001) and increased serum neutrophils (5.2 ± 2.7 vs. 3.7 ± 1.1 × 109 cells/L, p = 0.02). Logistic regression analysis demonstrated that reduced tissue eosinophil was predictive for poorly controlled disease (OR = 0.21, 95% CI [0.05, 0.83], p = 0.03). Receiver-operating characteristic analysis showed that need for rescue systemic corticosteroid was predicted at a serum neutrophil cut-off level of 5.75 × 109 cells/L (sensitivity = 80.0%, specificity = 96.9%, AUC = 0.938, p = 0.002).

CONCLUSION

Low tissue eosinophils and increased serum neutrophils while on biologics predict for poor response in the biological treatment of with CRSwNP. A serum neutrophil level of ≥5.75 × 109 cells/L predicts for poor response to current biologic therapy.

Biologic Therapies across Nasal Polyp Subtypes

Chronic rhinosinusitis with nasal polyposis is a common inflammatory condition, with subtypes like aspirin-exacerbated respiratory disease, allergic fungal rhinosinusitis, and central compartment atopic disease sharing a common type 2 inflammatory pathway. Respiratory biologic therapies have been developed that target type 2 inflammation. In this article, we discuss the use of respiratory biologic therapies for nasal polyposis in general, as well as within the various subtypes of nasal polyps. Further, we discuss future roles of novel biologic therapies targeting type 2 inflammation in nasal polyposis.

Management of Aspirin-Exacerbated Respiratory Disease: What Does the Future Hold?

Aspirin-exacerbated respiratory disease (AERD) is a subtype of chronic rhinosinusitis with polyps (CRSwNP) and asthma with higher recurrence of nasal polyps after surgery and severe asthma. Patients with CRSwNP and asthma should be screened for AERD by detailed history of aspirin/nonsteroidal anti-inflammatory drug reactions and review of medications that may mask aspirin reaction or directly by aspirin challenge. Treatment of AERD may require more intensive therapy, including endoscopic sinus surgery, daily aspirin therapy, leukotriene modifiers, or biologics.

Nasal polyp antibody-secreting cells display proliferation signature in aspirin-exacerbated respiratory disease

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) causes nasal obstruction and olfactory dysfunction. Aspirin-exacerbated respiratory disease (AERD) is the triad of CRSwNP, asthma, and respiratory reactions to COX-1 inhibitors. Patients with AERD have elevated nasal IL-5 levels and high numbers of antibody-secreting cells (ASCs), including plasma cells and plasmablasts, in their polyp tissue; in addition, their nasal polyp (NP) IgE levels are correlated with disease severity and recurrence of nasal polyposis.

OBJECTIVE

We sought to explore differences in the transcriptomic profile, activation markers, and IL-5Rα expression and function of NP ASCs from patients with AERD and CRSwNP.

METHODS

NP tissue was collected from patients with AERD and CRSwNP and digested into single-cell suspensions. NP cells were analyzed for protein expression by mass cytometry. For IL-5Rα functional studies, plasma cells were purified and cultured in vitro with or without IL-5 and analyzed by bulk RNA sequencing.

RESULTS

Compared with polyp tissue from patients with CRSwNP, polyp tissue from patients with AERD contained significantly more ASCs and had increased ASC expression of IL-5Rα. ASCs from patients with AERD expressed higher protein levels of B-cell activation and regulatory markers (CD40, CD19, CD32, and CD38) and the proliferation marker Ki-67. ASCs from patients with AERD also expressed more IL5RA, IGHE, and cell cycle- and proliferation-related transcripts (CCND2, MKI67, CDC25A, and CDC25B) than did ASCs from patients with CRSwNP. Stimulation of plasma cells from patients with AERD with IL-5 induced key cell cycle genes (CCND2 and PTP4A3), whereas IL-5 stimulation of ASCs from patients with CRSwNP induced few transcriptomic changes.

CONCLUSION

NP tissue ASCs from patients with AERD express higher levels of functional IL-5Rα and markers associated with cell cycling and proliferation than do ASCs from patients with aspirin-tolerant CRSwNP.

Chronic rhinosinusitis with nasal polyps: eosinophils versus B lymphocytes in disease pathogenesis

PURPOSE OF REVIEW

To highlight the current evidence that supports the view that eosinophils may not drive disease in chronic rhinosinusitis with nasal polyps (CRSwNP) and the emerging evidence for B cells as an important player in this disease.

RECENT FINDINGS

Eosinophil depletion studies in CRSwNP do not fully support a critical role for eosinophils in CRSwNP. Almost complete eosinophil depletion with dexpramipexole had no impact on polyp size reduction or clinical improvement. Anti-interleukin (IL)-5 and IL-5Rα inhibition were more effective though with less clinical impact when compared to anti-immunoglobulin E (IgE) or IL-4Rα inhibition strategies. As IL-5Rα is also expressed on CRSwNP derived IgE+ and IgG4+ plasma cells to the same extent as eosinophils, improvements in CRSwNP with IL-5 inhibition may suggest a role for B cells over eosinophils in CRSwNP. We review both eosinophils and B cells in the context of CRSwNP and highlight the current evidence that supports an emerging role for B cells.

SUMMARY

Despite many aspects of immunopathology in CRSwNP explainable by B cell dysfunction, B cells have so far been ignored in CRSwNP. Further work is needed, as targeting B cells may offer an exciting new therapeutic option in the future.

Eosinophils-from cradle to grave: An EAACI task force paper on new molecular insights and clinical functions of eosinophils and the clinical effects of targeted eosinophil depletion

Over the past years, eosinophils have become a focus of scientific interest, especially in the context of their recently uncovered functions (e.g. antiviral, anti-inflammatory, regulatory). These versatile cells display both beneficial and detrimental activities under various physiological and pathological conditions. Eosinophils are involved in the pathogenesis of many diseases which can be classified into primary (clonal) and secondary (reactive) disorders and idiopathic (hyper)eosinophilic syndromes. Depending on the biological specimen, the eosinophil count in different body compartments may serve as a biomarker reflecting the underlying pathophysiology and/or activity of distinct diseases and as a therapy-driving (predictive) and monitoring tool. Personalized selection of an appropriate therapeutic strategy directly or indirectly targeting the increased number and/or activity of eosinophils should be based on the understanding of eosinophil homeostasis including their interactions with other immune and non-immune cells within different body compartments. Hence, restoring as well as maintaining homeostasis within an individual's eosinophil pool is a goal of both specific and non-specific eosinophil-targeting therapies. Despite the overall favourable safety profile of the currently available anti-eosinophil biologics, the effect of eosinophil depletion should be monitored from the perspective of possible unwanted consequences.

Effect of Dupilumab on Type 2 Biomarkers in Chronic Rhinosinusitis With Nasal Polyps: SINUS-52 Study Results

OBJECTIVES

Chronic rhinosinusitis with nasal polyps (CRSwNP), asthma, and non-steroidal anti-inflammatory drug-exacerbated respiratory disease (NSAID-ERD) are frequent coexisting conditions and share type 2 inflammatory pathophysiology, with interleukin (IL)-4 and IL-13 as key cytokines. Dupilumab is a monoclonal antibody that blocks the shared receptor for IL-4 and IL-13. The objective of this analysis was to evaluate dupilumab's effect on type 2 inflammation biomarkers in patients with CRSwNP with/without coexisting asthma or NSAID-ERD from the SINUS-52 (NCT02898454) study.

METHODS

Patients received treatment with dupilumab or placebo for 52 weeks. Blood and urinary biomarkers were evaluated through 52 weeks, and nasal secretions and mucosa brushings through 24 weeks.

RESULTS

Of 447 patients, 60% had coexisting asthma and 27% had coexisting NSAID-ERD. At baseline, blood eotaxin-3, eosinophils, and periostin, nasal secretion eotaxin-3, and urinary leukotriene E4 were significantly higher in patients with coexisting NSAID-ERD than without. Dupilumab reduced eotaxin-3, thymus and activation-regulated chemokine, periostin, and total immunoglobulin E in blood, eotaxin-3, periostin, IL-5, and eosinophil cationic protein in nasal secretions, and leukotriene E4 in urine. Reductions were generally similar or greater in the subgroups with asthma and NSAID-ERD than without. Dupilumab also reduced MUC5AC and mast cell counts in nasal mucosa brushings.

CONCLUSION

Dupilumab reduced local and systemic type 2 inflammatory biomarkers in patients with CRSwNP, including mast cells in nasal mucosa and cysteinyl leukotrienes in urine. These findings provide insight into the processes driving CRSwNP and the mechanisms of dupilumab's therapeutic effects.

CLINICAL TRIAL REGISTRY NAME

SINUS-52 https://www.clinicaltrials.gov/ct2/show/NCT02898454.

CLINICALTRIALS.GOV IDENTIFIER

NCT02898454.

Safety and Efficacy of Dexpramipexole in Eosinophilic Asthma (EXHALE): A randomized controlled trial

BACKGROUND

There is a need for new and effective oral asthma therapies. Dexpramipexole, an oral eosinophil-lowering drug, has not previously been studied in asthma.

OBJECTIVE

We sought to evaluate the safety and efficacy of dexpramipexole in lowering blood and airway eosinophilia in subjects with eosinophilic asthma.

METHODS

We performed a randomized, double-blind, placebo-controlled proof-of-concept trial in adults with inadequately controlled moderate to severe asthma and blood absolute eosinophil count (AEC) greater than or equal to 300/μL. Subjects were randomly assigned (1:1:1:1) to dexpramipexole 37.5, 75, or 150 mg BID (twice-daily) or placebo. The primary end point was the relative change in AEC from baseline to week 12. Prebronchodilator FEV1 week-12 change from baseline was a key secondary end point. Nasal eosinophil peroxidase was an exploratory end point.

RESULTS

A total of 103 subjects were randomly assigned to dexpramipexole 37.5 mg BID (N = 22), 75 mg BID (N = 26), 150 mg BID (N = 28), or placebo (N = 27). Dexpramipexole significantly reduced placebo-corrected AEC week-12 ratio to baseline, in both the 150-mg BID (ratio, 0.23; 95% CI, 0.12-0.43; P < .0001) and the 75-mg BID (ratio, 0.34; 95% CI, 0.18-0.65; P = .0014) dose groups, corresponding to 77% and 66% reductions, respectively. Dexpramipexole reduced the exploratory end point of nasal eosinophil peroxidase week-12 ratio to baseline in the 150-mg BID (median, 0.11; P = .020) and the 75-mg BID (median, 0.17; P = .021) groups. Placebo-corrected FEV1 increases were observed starting at week 4 (nonsignificant). Dexpramipexole displayed a favorable safety profile.

CONCLUSIONS

Dexpramipexole demonstrated effective eosinophil lowering and was well tolerated. Additional larger clinical trials are needed to understand the clinical efficacy of dexpramipexole in asthma.

Distinct eicosanoid patterns in severe recalcitrant nasal polyposis

BACKGROUND

Although altered eicosanoid levels are related to disease severity in chronic rhinosinusitis with nasal polyps (CRSwNP), identifying patients prone to recurrent nasal polyps (NPs) is still difficult. We investigated levels of nasally secreted eicosanoids before and after NP surgery in patients with or without NP recurrence (NPR) and explored potential endotypes based on pre-surgical eicosanoid levels.

METHODS

Levels of leukotriene (LT) E4 , LTB4 , prostaglandin (PG) D2 , PGE2 and 15(S) hydroxyeicosatetraenoic acid (15[S]-HETE) were measured in nasal secretions with specific immunoassays at pre-surgery (n = 38) and 6 and 12 months post-surgery (n = 35), with NPR identified endoscopically. Pre- and post-surgical levels were compared between patients with and without NPR. Eicosanoid patterns among patients were explored with cluster analysis and evaluated with clinical parameters.

RESULTS

Patients with recurrent NPs had pronounced pre-surgical levels of nasal 15(S)-HETE, PGD2 and LTE4 . From pre-surgery to 12 months post-surgery, NPR was associated with significant decreases of 15(S)-HETE and PGD2 relative to non-recurrence, whereas levels of LTE4 decreased at 6 months but increased again at 12 months. Clustering revealed three potential endotypes. Clusters 1 and 3 featured high and low eicosanoid levels, respectively. Cluster 2 had higher levels of LTE4 and PGD2 , lower levels of PGE2 and LTB4 , and more cases of recurrent NPs and previous NP surgeries.

CONCLUSION

Elevated nasal LTE4 12 months post-surgery in NP recurrent subjects suggests that postoperative LTE4 measurements may indicate rapid NP regrowth. A distinct nasal eicosanoid profile may be used for the identification of the most severe recalcitrant patients in need of targeted immunomodulatory therapies.

Mepolizumab in chronic rhinosinusitis with nasal polyposis

Chronic rhinosinusitis with nasal polyposis (CRSwNP) is a heterogeneous upper airway disease that is prevalent globally. Recent research into the molecular basis of the disease has led to the development of biologics as a new therapeutic option for severe and recalcitrant forms of CRSwNP. Mepolizumab is a monoclonal antibody targeting IL-5, one of the signature cytokines of the type 2 immune response and which plays an important role in the pathogenesis of CRSwNP. Here we present the latest evidence behind mepolizumab, examining disease pathophysiology and pharmacology, as well as data from clinical trials, real-life studies and meta-analyses. As we welcome this promising step forward into precision medicine, we discuss practical issues and future perspectives on mepolizumab and biologics for CRSwNP.

Eosinophils and tissue remodeling: Relevance to airway disease

The ability of human tissue to reorganize and restore its existing structure underlies tissue homeostasis in the healthy airways, but in disease can persist without normal resolution, leading to an altered airway structure. Eosinophils play a cardinal role in airway remodeling both in health and disease, driving epithelial homeostasis and extracellular matrix turnover. Physiological consequences associated with eosinophil-driven remodeling include impaired lung function and reduced bronchodilator reversibility in asthma, and obstructed airflow in chronic rhinosinusitis with nasal polyps. Given the contribution of airway remodeling to the development and persistence of symptoms in airways disease, targeting remodeling is an important therapeutic consideration. Indeed, there is early evidence that eosinophil attenuation may reduce remodeling and disease progression in asthma. This review provides an overview of tissue remodeling in both health and airway disease with a particular focus on eosinophilic asthma and chronic rhinosinusitis with nasal polyps, as well as the role of eosinophils in these processes and the implications for therapeutic interventions. Areas for future research are also noted, to help improve our understanding of the homeostatic and pathological roles of eosinophils in tissue remodeling, which should aid the development of targeted and effective treatments for eosinophilic diseases of the airways.

Tezepelumab Efficacy in Patients with Severe, Uncontrolled Asthma with Comorbid Nasal Polyps in NAVIGATOR

Purpose

Tezepelumab, a human monoclonal antibody, blocks thymic stromal lymphopoietin. In the phase 3 NAVIGATOR study (NCT03347279), tezepelumab reduced annualized asthma exacerbation rates (AAERs) versus placebo, irrespective of baseline disease characteristics, and improved lung function and symptom control versus placebo in adults and adolescents with severe, uncontrolled asthma. We assessed the efficacy of tezepelumab in patients with severe asthma with or without nasal polyps (NPs) in the 2 years before randomization in NAVIGATOR.

Methods

Patients with severe asthma (N=1059) were randomized (1:1) and received tezepelumab 210 mg or placebo every 4 weeks subcutaneously for 52 weeks. Prespecified exploratory analyses included: AAER over 52 weeks and changes from baseline to week 52 in pre-bronchodilator forced expiratory volume in 1 second, Sino-Nasal Outcome Test (SNOT)-22 scores, and asthma control and health-related quality life (HRQoL) outcomes in NP subgroups. Changes from baseline in fractional exhaled nitric oxide (FeNO), blood eosinophil counts, total immunoglobulin E (IgE), eosinophil-derived neurotoxin (EDN), matrix metalloproteinase-10 (MMP-10), and serum interleukin (IL)-5, IL-6, IL-8 and IL-13 were assessed (post hoc).

Results

Tezepelumab reduced the AAER over 52 weeks versus placebo by 85% (95% confidence interval [CI]: 72, 92; n=118) and 51% (95% CI: 40, 60; n=941) in patients with and without NPs, respectively. At week 52, tezepelumab improved lung function, asthma control and HRQoL versus placebo in patients with and without NPs. Tezepelumab reduced SNOT-22 total scores (least-squares mean difference versus placebo [95% CI]) in patients with NPs at 28 weeks (-12.57 points [-19.40, -5.73]) and 52 weeks (-10.58 points [-17.75, -3.41]). At week 52, tezepelumab reduced blood eosinophil counts and FeNO, IgE, IL-5, IL-13, EDN and MMP-10 levels versus placebo, irrespective of NP status.

Conclusion

Tezepelumab resulted in clinically meaningful improvements in sino-nasal symptoms and asthma outcomes in patients with severe asthma with comorbid NPs.

Siglecs as potential targets of therapy in human mast cell- and/or eosinophil-associated diseases

Siglecs (sialic acid-binding immunoglobulin-like lectins) are a family of vertebrate glycan-binding cell-surface proteins. The majority mediate cellular inhibitory activity once engaged by specific ligands or ligand-mimicking molecules. As a result, Siglec engagement is now of interest as a strategy to therapeutically dampen unwanted cellular responses. When considering allergic inflammation, human eosinophils and mast cells express overlapping but distinct patterns of Siglecs. For example, Siglec-6 is selectively and prominently expressed on mast cells while Siglec-8 is highly specific for both eosinophils and mast cells. This review will focus on a subset of Siglecs and their various endogenous or synthetic sialoside ligands that regulate eosinophil and mast cell function and survival. It will also summarize how certain Siglecs have become the focus of novel therapies for allergic and other eosinophil- and mast cell-related diseases.

The Unified Airway Hypothesis: Evidence From Specific Intervention With Anti-IL-5 Biologic Therapy

The unified airway hypothesis proposes that upper and lower airway diseases reflect a single pathological process manifesting in different locations within the airway. Functional, epidemiological, and pathological evidence has supported this well-established hypothesis for some time. However, literature on the pathobiologic roles/therapeutic targeting of eosinophils and IL-5 in upper and lower airway diseases (including asthma, chronic rhinosinusitis with nasal polyps [CRSwNP], and nonsteroidal anti-inflammatory drug-exacerbated respiratory disease) has recently emerged. This narrative review revisits the unified airway hypothesis by searching the scientific literature for recent learnings and clinical trial/real-world data that provide a novel perspective on its relevance for clinicians. According to the available literature, eosinophils and IL-5 have important pathophysiological roles in both the upper and lower airways, although the impact of eosinophils and IL-5 may vary in asthma and CRSwNP. Some differential effects of anti-IL-5 and anti-IL-5-receptor therapies in CRSwNP have been observed, requiring further investigation. However, pharmaceutical targeting of eosinophils and IL-5 in patients with upper, lower, and comorbid upper and lower airway inflammation has led to clinical benefit, supporting the hypothesis that these are linked conditions manifesting in different locations. Consideration of this approach may improve patient care and aid clinical decision making.

The Role of Biologics in the Treatment of Chronic Rhinosinusitis

The last decade has seen significant developments in the field of biologics for the treatment of chronic rhinosinusitis with nasal polyps (CRSwNP). Translational research borne from knowledge of the pathophysiology of type 2 inflammatory disease of the lower airways and the strong association with CRSwNP, has led to major therapeutic breakthroughs, with phase 3 trials of four biologics completed at the time of writing, and more underway. This article explores the evidence behind biologics for CRSwNP, the guidance on their use and the health economic factors influencing their position amongst the established therapeutic options for this common chronic condition.

Mechanistic and clinical updates in AERD: 2021-2022

Aspirin-exacerbated respiratory disease (AERD) is a unique and often clinically severe disease affecting a subgroup of adults with asthma and chronic rhinosinusitis with nasal polyposis. Works published in 2021-2022 confirmed the critical role of lipid mediator dysregulation and mast cell activation and expanded our understanding of basophils, macrophages, fibrin dysregulation, and the 15-lipoxygenase pathway in disease pathogenesis. Translational studies established inflammatory heterogeneity in the upper and lower airway at baseline and during aspirin-induced respiratory reactions. Clinical cohorts provided insights into the mechanistic actions of frequently utilized biologic therapies in AERD. These advances are already changing clinical care delivery and affecting patient outcomes. Despite this, further work is needed to improve clinical tools to reliably diagnose AERD and identify factors that could prevent development of the disease altogether. Additionally, the impact of inflammatory heterogeneity on clinical trajectories and the utility and safety of combination biologic and daily aspirin therapies remains unanswered.

Biologicals in the treatment of chronic rhinosinusitis with nasal polyps – position of the Polish Society of Otorhinolaryngologists –Head and Neck Surgeons and the Polish Society of Allergology experts

Chronic rhinosinusitis with nasal polyps (CRSwNP) has a significant impact on the well-being and social functions of the patient. The generalized inflammatory process with the formation of nasal polyps and excess eosinophils in the mucosa of the paranasal sinuses is called type 2 inflammation, which is mediated by Th2 lymphocytes – cells of the immune system responsible for chronic inflammatory processes. Today, we also know the key pro-inflammatory mediators against which new drugs have been developed, the so-called biological drugs, are produced in cell lines. In this document, we present currently available biologicals approved for the treatment of patients with T2-related chronic rhinosinusitis.

Main Polymorphisms in Aspirin-Exacerbated Respiratory Disease

Aspirin exacerbated respiratory disease (AERD) is a condition caused by increased bronchoconstriction in people with asthma after taking aspirin or another NSAID. Molecular analysis of the human genome has opened up new perspectives on human polymorphisms and disease. This study was conducted to identify the genetic factors that influence this disease due to its unknown genetic factors. We evaluated research studies, letters, comments, editorials, eBooks, and reviews. PubMed/MEDLINE, Web of Sciences, Cochrane Library, and Scopus were searched for information. We used the keywords polymorphisms, aspirin-exacerbated respiratory disease, asthma, allergy as search terms. This study included 38 studies. AERD complications were associated with polymorphisms in ALOX15, EP2, ADRB2, SLC6A12, CCR3, CRTH2, CysLTs, DPCR1, DPP10, FPR2, HSP70, IL8, IL1B, IL5RA, IL-13, IL17RA, ILVBL, TBXA2R, TLR3, HLA-DRB and HLA-DQ, HLA-DR7, HLA-DP. AERD was associated with heterogeneity in gene polymorphisms, making it difficult to pinpoint specific gene changes. Therefore, diagnosing and treating AERD may be facilitated by examining common variants involving the disease.

Current Understanding of the Role of Eosinophils in CRSwNP and Implications for Treatment with Mepolizumab and Benralizumab

BACKGROUND

International consensus statements now subdivide chronic rhinosinusitis (CRS) into several phenotypes and endotypes, including the presence of polyps (CRSwNP) and eosinophilia (eCRSwNP). Biological treatments aimed at blocking eosinophilic inflammation in CRSwNP via interleukin 5 (IL5) or the interleukin 5 receptor (IL5R) have demonstrated limited efficacy thus far.

OBJECTIVE

To review the pathophysiology of eCRSwNP, the evidence for mepolizumab (anti-IL5) and benralizumab (anti-IL5R) in CRSwNP, and to highlight areas for future research and therapeutic intervention.

METHODS

Primary and secondary literature search.

RESULTS

Clinical trials on mepolizumab and benralizumab in CRSwNP are limited and restricted by trial design which prevents direct comparison with other interventions, including surgery. Both agents would appear to provide some benefit in reducing nasal polyp size but limited clinical patient benefit. Molecular biological research highlights that eCRSwNP can occur in the absence of IL5 and that other cells/cytokines play an important part in the disease's pathophysiology.

CONCLUSION

Blockade of IL5/IL5R alone would appear to provide limited "real life" clinical benefit in patients with CRSwNP due to the complexities of the pathophysiology of the condition. Therapy aimed at several simultaneous cytokine targets has logic but well-designed trials are unlikely to be forthcoming in the short term due to the financial cost and commercial conflicts of interest.

Mepolizumab for chronic rhinosinusitis with nasal polyps (SYNAPSE): In-depth sinus surgery analysis

BACKGROUND

Patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP) often require repeat sinus surgery. Mepolizumab reduced the need for sinus surgery in the SYNAPSE trial; this analysis sought to provide a more in-depth assessment of surgery endpoints in SYNAPSE.

METHODS

SYNAPSE was a double-blind Phase III trial (NCT03085797) in adults with recurrent, refractory, severe, CRSwNP eligible for repeat sinus surgery despite standard of care treatments and previous surgery. Patients were randomized (1:1) to mepolizumab 100 mg subcutaneously or placebo, plus standard of care, every 4 weeks for 52 weeks. Time to first inclusion on a waiting list for sinus surgery and time to first actual sinus surgery (both up to week 52) were assessed; the latter endpoint was also analyzed post hoc according to time since last sinus surgery before study screening and baseline blood eosinophil count.

RESULTS

Among 407 patients (mepolizumab: 206; placebo: 201), mepolizumab versus placebo reduced the risk of being included on a waiting list for sinus surgery (week 52 Kaplan-Meier probability estimate [95% confidence interval]: 13.9% [9.8%, 19.5%] vs. 28.5% [22.7%, 35.4%]). Mepolizumab versus placebo reduced the risk of sinus surgery irrespective of time (<3 vs ≥3 years) since patients' last sinus surgery prior to study screening (hazard ratios [95% confidence intervals] 0.28 [0.09, 0.84] and 0.50 [0.26, 0.98], respectively) and baseline blood eosinophil count.

CONCLUSIONS

Mepolizumab reduced the risk of further sinus surgery in patients with recurrent, refractory, severe CRSwNP, irrespective of the patient baseline characteristics assessed.

Updates on immune mechanisms in aspirin-exacerbated respiratory disease

Aspirin-exacerbated respiratory disease has fascinated and frustrated specialists in allergy/immunology, pulmonology, and otorhinolaryngology for decades. It generally develops in previously healthy young adults and is unremitting and challenging to treat. The classical triad of asthma, nasal polyposis, and pathognomonic respiratory reactions to aspirin and other cyclooxygenase-1 inhibitors is accompanied by high levels of mast cell activation, cysteinyl leukotriene production, platelet activation, and severe type 2 respiratory inflammation. The "unbraking" of mast cell activation and further cysteinyl leukotriene generation induced by cyclooxygenase-1 inhibition reflect an idiosyncratic dependency on cyclooxygenase-1-derived products, likely prostaglandin E2, to maintain a tenuous homeostasis. Although cysteinyl leukotrienes are clear disease effectors, little else was known about their cellular sources and targets, and the contributions from other mediators and type 2 respiratory inflammation effector cells to disease pathophysiology were unknown until recently. The applications of targeted biological therapies, single-cell genomics, and transgenic animal approaches have substantially advanced our understanding of aspirin-exacerbated respiratory disease pathogenesis and treatment and have also revealed disease heterogeneity. This review covers novel insights into the immunopathogenesis of aspirin-exacerbated respiratory disease from each of these lines of research, including the roles of lipid mediators, effector cell populations, and inflammatory cytokines, discusses unanswered questions regarding cause and pathogenesis, and considers potential future therapeutic options.

Mepolizumab for the treatment of chronic rhinosinusitis with nasal polyps in adults

INTRODUCTION

The treatment paradigm for chronic rhinosinusitis with nasal polyps (CRSwNP) is complex, consisting of a combination of conservative, medical and surgical management. High rates of recurrence despite current standard of care has led to the search for treatments that can improve outcomes and limit the treatment burden for patients living with this chronic condition.

AREAS COVERED

Eosinophils are granulocytic white blood cells that proliferate as part of the innate immune response. IL5 is an inflammatory cytokine implicated in the development of eosinophil-associated diseases that has emerged as a target for biologic therapy. Mepolizumab (NUCALA) is a humanized antiIL5 monoclonal antibody that represents a novel therapeutic approach to CRSwNP. The results of multiple clinical trials are encouraging but its real-world implementation requires a thorough cost-benefit analysis across a range of clinical situations.

EXPERT OPINION

: Mepolizumab is an emerging biologic therapy that shows promising potential for the treatment of CRSwNP. It appears to provide both objective and subjective improvement as an addon therapy to standard of care treatment. Its specific role in treatment algorithms remains a topic of discussion. Future research surrounding its efficacy and cost effectiveness as compared to alternative options is needed.

Living without eosinophils: evidence from mouse and man

The enduring view of eosinophils, as immune effector cells whose primary function is host defence against infection by helminths and other microbial pathogens, sets the stage for a fundamental question regarding the safety of therapeutic eosinophil depletion. If eosinophils are significantly reduced or altogether depleted in an effort to alleviate the negative effects of tissue eosinophilia and eosinophilic inflammation in conditions such as asthma, COPD, chronic rhinosinusitis with nasal polyps, eosinophilic granulomatosis with polyangiitis and hypereosinophilic syndrome, would these patients become susceptible to infection or another illness? Development of mouse models in which the eosinophil lineage has been ablated, observations in patients naturally lacking eosinophils and data from studies of eosinophil-depleting medical therapies indicate that the absence of eosinophils is not detrimental to health. The evidence available to date, as presented in this review, supports the conclusion that even if certain homeostatic roles for the eosinophil may be demonstrable in controlled animal models and human in vitro settings, the evolution of the human species appears to have provided sufficient immune redundancy such that one may be hale and hearty without eosinophils.

Updates in biologic therapy for chronic rhinosinusitis with nasal polyps and NSAID-exacerbated respiratory disease

Chronic rhinosinusitis with nasal polyps (CRSwNP) associated with type 2 inflammation and non-steroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD) can be difficult to control with standard medical therapy and sinus surgery. In this group, biologicals are potentially promising treatment options. The phase III clinical trials for omalizumab, dupilumab, mepolizumab and benralizumab in CRSwNP have demonstrated favourable outcomes. Moving forward, direct comparisons among biologicals, refining patient selection criteria for specific biologicals, determining optimal treatment duration and monitoring long-term outcomes are areas of emerging interest. This review summarizes the clinical evidence from the recent 2 years on the role of biologicals in severe CRSwNP and N-ERD, and proposes an approach towards decision-making in their use.

Over-expression of CRTH2 indicates eosinophilic inflammation and poor prognosis in recurrent nasal polyps

Background

Chronic rhinosinusitis with nasal polyps (CRSwNP) is often characterized by recurrent nasal polyp (NP) growth following surgical removal, but the mechanisms are still not clear. This study aimed to investigate the expression of chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) receptor on NP and the role it plays in eosinophil inflammation and polyp recurrence.

Methods

Forty-one CRSwNPs patients and seventeen controls were enrolled in this study. mRNA was extracted from nasal tissues and evaluated for expression of CRTH2. Immunofluorescence staining was performed to confirm the distribution and expression of CRTH2 protein. CRTH2 expression on peripheral blood eosinophils was quantified by flow cytometry. The eosinophil count and clinical implications were also evaluated and their correlations with CRTH2 expression were analyzed.

Results

Nasal polyps displayed increased expression of CRTH2 in mRNA level compared with control samples, with the highest expression observed in recurrent NP. Immunofluorescence confirmed over-expression of CRTH2 in recurrent NP and this was independent of the concurrent presence of asthma. CRTH2 expression was positively correlated with tissue eosinophil number (Spearman’s ρ=0.69, P&lt;0.001) and the postoperative sino-nasal outcome test-22 (SNOT-22) score (Spearman’s ρ=0.67, P&lt;0.001). Receiver operating characteristic (ROC) curves revealed CRTH2 was more predictive for NP recurrence compared to either eosinophil number and concomitant asthma, with an area under the ROC curve of 0.9107.

Conclusion

The over-expression of CRTH2 in recurrent nasal polyps correlates with greater eosinophilic inflammation and poor prognosis which is independent of concomitant asthma.

The roles of eosinophils and interleukin-5 in the pathophysiology of chronic rhinosinusitis with nasal polyps

Chronic rhinosinusitis with nasal polyps (CRSwNP) is generally associated with eosinophilic tissue infiltration linked to type 2 inflammation and characterized by elevated levels of interleukin (IL)-5 and other type 2 inflammatory mediators. Although distinct and overlapping contributions of eosinophils and IL-5 to CRSwNP pathology are still being explored, they are both known to play an important role in NP inflammation. Eosinophils secrete numerous type 2 inflammatory mediators including granule proteins, enzymes, cytokines, chemokines, growth factors, lipids, and oxidative products. IL-5 is critical for the differentiation, migration, activation, and survival of eosinophils but is also implicated in the biological functions of mast cells, basophils, innate lymphoid cells, B cells, and epithelial cells. Results from clinical trials of therapeutics that target type 2 inflammatory mediators (including but not limited to anti-IL-5, anti-immunoglobulin-E, and anti-IL-4/13) may provide further evidence of how eosinophils and IL-5 contribute to CRSwNP. Finally, the association between eosinophilia/elevated IL-5 and greater rates of NP recurrence after endoscopic sinus surgery (ESS) suggests that these mediators may have utility as biomarkers of NP recurrence in diagnosing and assessing the severity of CRSwNP. This review provides an overview of eosinophil and IL-5 biology and explores the literature regarding the role of these mediators in CRSwNP pathogenesis and NP recurrence following ESS. Based on current published evidence, we suggest that although eosinophils play a key role in CRSwNP pathophysiology, IL-5, a cytokine that activates these cells, also represents a pertinent and effective treatment target in patients with CRSwNP.

Mepolizumab Improves Outcomes of Chronic Rhinosinusitis with Nasal Polyps in Severe Asthmatic Patients: A Multicentric Real-Life Study

Objective: The upcoming introduction of mepolizumab represents a promising treatment for chronic rhinosinusitis with nasal polyps (CRSwNP). The present study aimed to evaluate the effectiveness of mepolizumab on sinonasal outcomes of comorbid CRSwNP and severe asthma in a real-life setting. The primary endpoint was to evaluate changes in the SinoNasal Outcome Test (SNOT)-22 score, Nasal Polyp (NP) score, and blood eosinophil count during a 12-month treatment with mepolizumab. Secondary endpoints were to quantify mepolizumab’s effects on the mentioned parameters, identify clinical variables influencing the degree of response to treatment, and portray responder and nonresponder patients. Methods: A multicentric retrospective no-profit observational study on severe asthmatic patients, treated with mepolizumab, and comorbid CRSwNP was conducted. All patients were followed for at least 12 months. SNOT-22 score, NP score, and blood eosinophil count (and other CRS-specific variables) were collected at baseline and after 12 months. Results: Forty-three patients were included. A statistically significant reduction was observed for SNOT-22 score (mean t0 SNOT-22 54.8 ± 25.9; mean t12 SNOT-22 31.5 ± 21.3, p < 0.0001), NP score (median t0 NPS 3 (IQR 3); median t12 NPS 2 (IQR 4), p < 0.0001), and blood eosinophil count (mean t0 blood eosinophils 804.7 ± 461.5 cell/µL; mean t12 blood eosinophils 107.5 ± 104.6 cell/µL, p < 0.0001) after 12 months of treatment. Twenty patients (47%) gained improvement both in clinical and endoscopic outcome. Mepolizumab responder patients presented a t0 SNOT-22 significantly higher than nonresponders (p = 0.0011). Conclusions: Mepolizumab improved CRSwNP outcomes in a population of severe asthmatic patients. No clinical feature emerged to outline the profile of a “typical” responder patient, except for baseline SNOT-22 score, which seemed to affect the response to treatment. Further studies would be necessary to supplement these preliminary evaluations.

Rapid and sustained effect of dupilumab on clinical and mechanistic outcomes in aspirin-exacerbated respiratory disease

BACKGROUND

Dupilumab, a mAb targeting IL-4Rα, improves upper and lower airway symptoms in patients with aspirin-exacerbated respiratory disease (AERD), but the mechanisms leading to clinical improvement are not fully elucidated.

OBJECTIVE

Our aim was to identify the mechanistic basis of clinical improvement in patients with AERD treated with dupilumab.

METHODS

A total of 22 patients with AERD were treated with dupilumab for 3 months for severe asthma and/or chronic rhinosinusitis with nasal polyps. Clinical outcomes were assessed at baseline and at 1 and 3 months after initiation of dupilumab. Nasal fluid, urine, blood, and inferior turbinate scrapings were collected at the 3 time points for determination of mediator levels, cellular assays, and RNA sequencing.

RESULTS

Participants had rapid improvement in clinical measures, including sense of smell, sinonasal symptoms, and lung function after 1 month of treatment with dupilumab; the improvements were sustained after 3 months of dupilumab. Baseline severity of smell loss was correlated with lower nasal prostaglandin E₂ levels. Dupilumab increased nasal prostaglandin E₂ level and decreased levels of nasal albumin, nasal and urinary leukotriene E₄, and serum and nasal IgE. Transcripts related to epithelial dysfunction and leukocyte activation and migration were downregulated in inferior turbinate tissue after treatment with dupilumab. There were no dupilumab-induced changes in nasal eosinophilia.

CONCLUSION

Inhibition of IL-4Rα in AERD led to rapid improvement in respiratory symptoms and smell, with a concomitant improvement in epithelial barrier function, a decrease in inflammatory eicosanoid levels, and an increase in the anti-inflammatory eicosanoid prostaglandin E₂ level. The therapeutic effects of dupilumab are likely due to decreased IL-4Rα signaling on respiratory tissue granulocytes, epithelial cells, and B cells.

Chronic Rhinosinusitis, S. aureus Biofilm and Secreted Products, Inflammatory Responses, and Disease Severity

Chronic rhinosinusitis (CRS) is a persistent inflammation of the nasal cavity and paranasal sinuses associated with tissue remodelling, dysfunction of the sinuses’ natural defence mechanisms, and induction of different inflammatory clusters. The etiopathogenesis of CRS remains elusive, and both environmental factors, such as bacterial biofilms and the host’s general condition, are thought to play a role. Bacterial biofilms have significant clinical relevance due to their potential to cause resistance to antimicrobial therapy and host defenses. Despite substantial medical advances, some CRS patients suffer from recalcitrant disease that is unresponsive to medical and surgical treatments. Those patients often have nasal polyps with tissue eosinophilia, S. aureus-dominant mucosal biofilm, comorbid asthma, and a severely compromised quality of life. This review aims to summarise the contemporary knowledge of inflammatory cells/pathways in CRS, the role of bacterial biofilm, and their impact on the severity of the disease. Here, an emphasis is placed on S. aureus biofilm and its secreted products. A better understanding of these factors might offer important diagnostic and therapeutic perceptions for recalcitrant disease.

An update on the currently available and emerging synthetic pharmacotherapy for uncontrolled asthma

INTRODUCTION

: The treatment of uncontrolled asthma has improved because of triple therapy that includes a long-acting muscarinic antagonist (LAMA) and biological drugs, but several patients are resistant to corticosteroids and/or cannot achieve adequate asthma control using such therapies.

AREAS COVERED

: Herein, the authors review the current and emerging synthetic pharmacotherapy for uncontrolled asthma to overcome obstacles and limitations of biological therapies. The authors also provide their expert perspectives and opinion on the treatment of uncontrolled asthma.

EXPERT OPINION

: LAMAs should be added to inhaled corticosteroid/long-acting β₂-agonist combinations much earlier than currently recommended by the Global Initiative for Asthma strategy because they can influence the course of small airways disease, reducing lung hyperinflation and improving asthma control. Biological therapies are a major advance in the treatment of severe asthma, but their use is still very limited for several reasons. An alternative to overcome the use of biological therapies is to synthesise compounds that target inflammation-signalling pathways. Several pathways have been identified as potential targets to design either therapeutic or prophylactic drugs against asthma. Some new compounds have already been tested in humans, but results have often been disappointing probably because existing phenotypic and endotypic variants may unpredictably limit the therapeutic value of blocking a specific pathway in most asthmatics, although there may be a substantial benefit for a subgroup of patients.

Difficult-to-Control Asthma Management in Adults

The management of difficult-to-control asthma remains a significant challenge, which frequently requires the input of the wider multidisciplinary team. This review covers the importance of systematic assessment, phenotyping, treatment options at step 4, an overview of biologics and novel therapies for type 2 (T2) inflammation, and nonpharmacological interventions. Once people have been identified as suffering from difficult-to-control asthma, it is important to use the systematic assessment process to allow accurate diagnosis and optimization of adherence as well as identification and treatment of any relevant comorbidities. Before initiating a biologic, it is important to optimize inhaled therapies and sufficiently phenotype individual patients to allow for the logical use of biologic agents targeting T2 inflammation. For patients who either do not have evidence of T2 inflammation or remain symptomatic despite biologics, attention should be paid to the available nonpharmacological interventions. Difficult-to-treat asthma remains an area of significant unmet need, but improvements in models of service delivery and the ongoing pharmacological pipeline are causes for significant optimism that sooner rather than later there will no longer be asthmatic patients who are difficult to treat.

Effects of Therapeutic Antibodies on Gene and Protein Signatures in Asthma Patients: A Comparative Systematic Review

Several biologic therapies that target inflammatory modulators are now used for treating patients with uncontrolled, severe asthma. Knowledge about how this type of treatment modifies the molecular milieu is rapidly increasing. Thus, this systematic review aimed to compile the reported effects of therapeutic antibodies on the transcriptome or proteome of asthma patients. Studies of asthmatic patients under biological treatment describing transcriptomic or proteomic changes upon treatment were included. Preclinical or single gene/protein studies were not considered. PubMed and Scopus search was performed in August and September 2021. Following PRISMA guidelines and GRADE recommendations, we selected 12 studies on gene or protein expression changes in patients treated with the antibodies currently approved by EMA and the FDA. All studies were at low risk of bias as per the RoB2 tool. Different gene clusters have been identified to change upon omalizumab treatment, found a reduction in eosinophil-associated gene signatures after benralizumab treatment, and protein profiles were different in patients treated with mepolizumab and in those treated with benralizumab. The main potential biomarkers proposed by the selected studies are shown. These results may contribute to discovering biomarkers of response and selecting the best therapy for each patient.

Biologics in Asthma: A Molecular Perspective to Precision Medicine

Recent developments in therapeutic strategies have provided alternatives to corticosteroids as the cornerstone treatment for managing airway inflammation in asthma. The past two decades have witnessed a tremendous boost in the development of anti-cytokine monoclonal antibody (mAb) therapies for the management of severe asthma. Novel biologics that target eosinophilic inflammation (or type 2, T2 inflammation) have been the most successful at treating asthma symptoms, though there are a few in the drug development pipeline for treating non-eosinophilic or T2-low asthma. There has been significant improvement in clinical outcomes for asthmatics treated with currently available monoclonal antibodies (mAbs), including anti-immunoglobulin (Ig) E, anti-interleukin (IL)-4 receptor α subunit, anti-IL-5, anti-IL-5Rα, anti-IL-6, anti-IL-33, and anti-thymic stromal lymphopoietin (TSLP). Despite these initiatives in precision medicine for asthma therapy, a significant disease burden remains, as evident from modest reduction of exacerbation rates, i.e., approximately 40-60%. There are numerous studies that highlight predictors of good responses to these biologics, but few have focused on those who fail to respond adequately despite targeted treatment. Phenotyping asthmatics based on blood eosinophils is proving to be inadequate for choosing the right drug for the right patient. It is therefore pertinent to understand the underlying immunology, and perhaps, carry out immune endotyping of patients before prescribing appropriate drugs. This review summarizes the immunology of asthma, the cytokines or receptors currently targeted, the possible mechanisms of sub-optimal responses, and the importance of determining the immune make-up of individual patients prior to prescribing mAb therapy, in the age of precision medicine for asthma.

Highlights in the advances of chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a complex upper airway inflammatory disease with a broad spectrum of clinical variants. As our understanding of the disease pathophysiology evolves, so too does our philosophy towards the approach and management of CRS. Endotyping is gaining favour over phenotype-based classifications, owing to its potential in prognosticating disease severity and delivering precision treatment. Endotyping is especially useful in challenging CRS with nasal polyposis cases, for whom novel treatment options such as biologicals are now available. The latest European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS2020) reflects these changes with updated rhinosinusitis classifications and new integrated care pathways. With the coronavirus disease 2019 (COVID-19) pandemic, physicians and rhinologists have to balance the responsibility of managing their patients' upper airway while adequately protecting themselves from droplet and aerosol transmission. This review summarises the key updates from EPOS2020, endotype-based classification and biomarkers. The role of biologicals in CRS and the lessons we can draw from their use in severe asthma will be examined. Finally, the principles of CRS management during COVID-19 will also be discussed.

Defining the Allergic Endotype of Chronic Rhinosinusitis by Structured Histopathology and Clinical Variables

BACKGROUND

Atopy has a strong association with chronic rhinosinusitis (CRS).

OBJECTIVE

To understand whether patients with atopy and CRS can be defined by markers of tissue histopathology, systemic biomarkers, and clinical factors, which may guide their response to new pharmacologic agents.

METHODS

In a retrospective cohort of CRS patients who underwent functional endoscopic sinus surgery, a structured histopathology report consisting of 12 variables, comorbid conditions, preoperative total serum IgE levels, and preoperative modified Lund-Kennedy endoscopic and sinonasal outcome test (SNOT-22) scores were compared between atopic CRS (aCRS) and non-aCRS control patients in a multivariable model.

RESULTS

A total of 380 CRS patients were enrolled, 286 of whom had comorbid atopy (aCRS). Compared with non-aCRS, aCRS patients had significantly higher preoperative total SNOT-22 scores (40.45 ± 22.68 vs 29.70 ± 20.68, P = .015) and symptom-specific SNOT-22 scores in all domains except psychological dysfunction. Relative to non-aCRS, aCRS patients had increased tissue eosinophilia (P < .0001), eosinophil aggregates (P < .0001), Charcot-Leyden crystals (P < .04), fibrosis (P < .02), total serum IgE levels (P < .04), polyploid disease (P < .001), and a prevalence of comorbid asthma (P < .0001) and aspirin exacerbated respiratory disease (AERD) (P < .003). Patients with aCRS demonstrated increased tissue eosinophilia compared with non-aCRS patients even after controlling for polypoid disease, asthma, and AERD.

CONCLUSION

In the context of CRS, atopy appears to be a specific predictor of CRS severity linked to specific histopathologic variables, including enhanced eosinophilic aggregates. Moving forward, allergic status may be a useful way to identify an atopic endotype of CRS patients. Furthermore, after surgery, patients are often maintained on intranasal corticosteroids. In patients whose disease is unresponsive to steroids, we may look to atopic status to identify another management therapy. Atopic CRS patients, irrespective of polyp and asthmatic status, could be optimal candidates for biologic agents such as T-helper cell, eosinophil, and/or IgE-targeted therapies.

Efficacy and safety of benralizumab in chronic rhinosinusitis with nasal polyps: A randomized, placebo-controlled trial

BACKGROUND

Eosinophilic inflammation has been implicated in the pathogenesis, severity, and treatment responsiveness of chronic rhinosinusitis with nasal polyps (CRSwNP).

OBJECTIVE

We sought to assess the efficacy and safety of benralizumab-mediated eosinophil depletion for treating CRSwNP.

METHODS

The phase 3 OSTRO study enrolled patients with severe CRSwNP who were symptomatic despite treatment with intranasal corticosteroids and who had a history of systemic corticosteroid (SCS) use and/or surgery for nasal polyps (NP). Patients were randomized 1:1 to treatment with benralizumab 30 mg or placebo every 4 weeks for the first 3 doses and every 8 weeks thereafter. Coprimary end points were change from baseline to week 40 in NP score (NPS) and patient-reported mean nasal blockage score reported once every 2 weeks.

RESULTS

The study population comprised 413 randomized patients (207 in the benralizumab group and 206 in the placebo group). Benralizumab significantly improved NPS and nasal blockage score compared to placebo at week 40 (P ≤ .005). Improvements in Sinonasal Outcome Test 22 score at week 40, time to first NP surgery and/or SCS use for NP, and time to first NP surgery were not statistically significant between treatment groups. Nominal significance was obtained for improvement in difficulty in sense of smell score at week 40 (P = .003). Subgroup analyses suggested influences of comorbid asthma, number of NP surgeries, sex, body mass index, and baseline blood eosinophil count on treatment effects. Benralizumab was safe and well tolerated.

CONCLUSION

Benralizumab, when added to standard-of-care therapy, reduced NPS, decreased nasal blockage, and reduced difficulty with sense of smell compared to placebo in patients with CRSwNP.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03401229.

Defining the Efficacy of Omalizumab in Nasal Polyposis: A POLYP 1 and POLYP 2 Subgroup Analysis

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disease with variable underlying pathophysiologies. Numerous patient factors have been linked to differences in disease severity, control, and response to treatment, including asthma status, aspirin sensitivity, previous sinonasal surgery, and blood eosinophil levels.

OBJECTIVE

The present study examines the efficacy of the anti-immunoglobulin E therapy, omalizumab, versus placebo in patients with CRSwNP from the replicate POLYP 1 (NCT03280550) and POLYP 2 (NCT03280537) trials, grouped by inherent patient characteristics to determine the response to therapy.

METHODS

Patients in prespecified subgroups from POLYP 1 and POLYP 2 (studies pooled for analysis) were examined. Subgroups included blood eosinophil count at baseline (>300 or ≤300 cells/μL), previous sinonasal surgery (yes or no), asthma status (yes or no), and aspirin sensitivity status (yes or no). Subgroups were examined for subgroup-specific adjusted mean difference (95% confidence interval [CI]) (omalizumab-placebo) in change from baseline at week 24 in Nasal Congestion Score (NCS), Nasal Polyp Score (NPS), Sino-Nasal Outcome Test-22 (SNOT-22), Total Nasal Symptom Score (TNSS), and University of Pennsylvania Smell Identification Test (UPSIT).

RESULTS

Adjusted mean difference (95% CI) (omalizumab-placebo) in NCS, NPS, SNOT-22, TNSS, and UPSIT change from baseline at week 24 consistently favored omalizumab treatment over placebo in patients with blood eosinophil count >300 and ≤300 cells/μL, with or without previous sinonasal surgery, asthma, and aspirin sensitivity.

CONCLUSION

Together, these data suggest broad efficacy of omalizumab across clinical and patient-reported outcomes in patients with CRSwNP, independent of the underlying patient factors examined, including those with high eosinophil levels and those who have undergone previous surgery, which are associated with high recurrence.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifiers: POLYP 1: ClinicalTrials.gov identifier NCT03280550 (https://clinicaltrials.gov/ct2/show/NCT03280550); POLYP 2: ClinicalTrials.gov identifier NCT03280537 (https://clinicaltrials.gov/ct2/show/NCT03280537).

Innate immune cell dysregulation drives inflammation and disease in aspirin-exacerbated respiratory disease

Aspirin-exacerbated respiratory disease (AERD) is a complex inflammatory disorder that is not generally viewed as a disease involving the adaptive immune system but instead one largely driven by the innate immune system. This article focuses on the cellular dysregulation involving 4 central cell types: eosinophils, basophils, mast cells, and innate lymphoid type 2 cells. AERD can be envisioned as involving a self-perpetuating vicious circle in which mediators produced by a differentiated activated epithelial layer, such as IL-25, IL-33, and thymic stromal lymphopoietin, engage and activate each of these innate immune cells. The activation of these innate immune cells with their production of additional cytokine/chemokine and lipid mediators leads to further recruitment and activation of these innate immune cells. More importantly, numerous mediators produced by these innate immune cells provoke the epithelium to induce further inflammation. This self-perpetuating cycle of inflammation partially explains both current interventions suggested to ameliorate AERD (eg, aspirin desensitization, leukotriene modifiers, anti-IL-5/IL-5 receptor, anti-IL-4 receptor, and anti-IgE) and invites exploration of novel targets as specific therapies for this condition (prostaglandin D₂ antagonists or cytokine antagonists [IL-25, IL-33, thymic stromal lymphopoietin]). Several of these interventions currently show promise in small retrospective analyses but now require definite clinical trials.

Rethinking neutrophils and eosinophils in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) often is characterized by an eosinophilic inflammatory pattern, nowadays referred to as type 2 inflammation, although the mucosal inflammation is dominated by neutrophils in about a third of the patients. Neutrophils are typically predominant in 50% of patients with CRS without nasal polyps, but also are found to play a role in patients with severe type 2 CRS with nasal polyp disease. This review aims at summarizing the current understanding of the eosinophilic and neutrophilic inflammation in CRS pathophysiology, and provides a discussion of their reciprocal interactions and the clinical impact of the mixed presentation in patients with severe type 2 CRS with nasal polyps. A solid understanding of these interactions is of utmost importance when treating uncontrolled severe CRS with nasal polyps with biologicals that are preferentially directed toward type 2 inflammation. We here focus on recent findings on both eosinophilic and neutrophilic granulocytes, their subgroups and the activation status, and their interactions in CRS.

Mepolizumab targets multiple immune cells in aspirin-exacerbated respiratory disease

BACKGROUND

Eosinophilic asthma and nasal polyposis are hallmarks of aspirin-exacerbated respiratory disease (AERD), and IL-5 inhibition has been shown to provide therapeutic benefit. However, IL-5Rα is expressed on many cells in addition to eosinophils, and the mechanisms by which IL-5 inhibition leads to clinical benefit in eosinophilic asthma and nasal polyposis are unlikely to be due exclusively to antieosinophil effects.

OBJECTIVE

We sought to identify the mechanisms by which anti-IL-5 treatment with mepolizumab improves respiratory inflammation in AERD.

METHODS

The clinical characteristics, circulating granulocytes, nasal scraping transcripts, eosinophilic cationic protein, tryptase, and antibody levels, and urinary and nasal eicosanoid levels were measured for 18 subjects with AERD who were taking mepolizumab and compared with those of 18 matched subjects with AERD who were not taking mepolizumab.

RESULTS

Subjects taking mepolizumab had significantly fewer peripheral blood eosinophils and basophils, and those cells that remained had higher surface CRTH2 expression than did the cells from subjects not taking mepolizumab. Nasal prostaglandin F_2α, prostaglandin D₂ metabolites, leukotriene B₄, and thromboxane levels were lower in subjects taking mepolizumab, as were urinary levels of tetranor-prostaglandin D₂ and leukotriene E₄. The nasal epithelial cell transcripts that were overexpressed among subjects with AERD who were taking mepolizumab were enriched for genes involved in tight junction formation and cilium organization. Nasal and urinary prostaglandin E₂, tryptase, and antibody levels were not different between the 2 groups.

CONCLUSION

IL-5 inhibition in AERD decreases production of inflammatory eicosanoids and upregulates tight junction-associated nasal epithelial cell transcripts, likely due to decreased IL-5 signaling on tissue mast cells, eosinophils, and epithelial cells. These direct effects on multiple relevant immune cells contribute to the mechanism of benefit afforded by mepolizumab.

The Choice of Biologics in Patients with Severe Chronic Rhinosinusitis with Nasal Polyps

Patients with severe chronic rhinosinusitis with nasal polyps represent an unmet clinical need in terms of recurrent disease despite current medical and surgical therapy. Targeting type 2 inflammatory cytokines (IL4/5/13) appears to be a promising therapeutic approach for such patients akin to what has already been seen in severe asthma. An indirect comparison from phase 3 placebo-controlled trials has shown relative improvements in the coprimary end point of nasal polyp score (NPS) ranging from a 15% reduction (-0.8 units) with mepolizumab, 18% with omalizumab (-1.14 units), and 35% (-2.06 units) with dupilumab. This trend was mirrored by relative improvements in health status with the 22-item Sinonasal Outcome Test score showing a 21% reduction (-13.7 units) with mepolizumab, 27% (-16.1 units) with omalizumab, and 43% (-21.1 units) with dupilumab, all exceeding the minimal clinically important difference of 8.9 units. All biologics improved the coprimary end point of nasal airway blockage and also reduced the need for rescue medical and/or surgical polypectomy. We advocate performing real-life studies looking at the response to biologics in patients who are at increased risk for disease recurrence, including initial optimal medical and surgical polyp clearance before commencing biologics.