Relationship between pretreatment specific IgE and the response to omalizumab therapy

Association between pre-biologic T2-biomarker combinations and response to biologics in patients with severe asthma

Background

To date, studies investigating the association between pre-biologic biomarker levels and post-biologic outcomes have been limited to single biomarkers and assessment of biologic efficacy from structured clinical trials.

Aim

To elucidate the associations of pre-biologic individual biomarker levels or their combinations with pre-to-post biologic changes in asthma outcomes in real-life.

Methods

This was a registry-based, cohort study using data from 23 countries, which shared data with the International Severe Asthma Registry (May 2017-February 2023). The investigated biomarkers (highest pre-biologic levels) were immunoglobulin E (IgE), blood eosinophil count (BEC) and fractional exhaled nitric oxide (FeNO). Pre- to approximately 12-month post-biologic change for each of three asthma outcome domains (i.e. exacerbation rate, symptom control and lung function), and the association of this change with pre-biologic biomarkers was investigated for individual and combined biomarkers.

Results

Overall, 3751 patients initiated biologics and were included in the analysis. No association was found between pre-biologic BEC and pre-to-post biologic change in exacerbation rate for any biologic class. However, higher pre-biologic BEC and FeNO were both associated with greater post-biologic improvement in FEV1 for both anti-IgE and anti-IL5/5R, with a trend for anti-IL4Rα. Mean FEV1 improved by 27-178 mL post-anti-IgE as pre-biologic BEC increased (250 to 1000 cells/µL), and by 43-216 mL and 129-250 mL post-anti-IL5/5R and -anti-IL4Rα, respectively along the same BEC gradient. Corresponding improvements along a FeNO gradient (25-100 ppb) were 41-274 mL, 69-207 mL and 148-224 mL for anti-IgE, anti-IL5/5R, and anti-IL4Rα, respectively. Higher baseline BEC was also associated with lower probability of uncontrolled asthma (OR 0.392; p=0.001) post-biologic for anti-IL5/5R. Pre-biologic IgE was a poor predictor of subsequent pre-to-post-biologic change for all outcomes assessed for all biologics. The combination of BEC + FeNO marginally improved the prediction of post-biologic FEV1 increase (adjusted R2: 0.751), compared to BEC (adjusted R2: 0.747) or FeNO alone (adjusted R2: 0.743) (p=0.005 and <0.001, respectively); however, this prediction was not improved by the addition of IgE.

Conclusions

The ability of higher baseline BEC, FeNO and their combination to predict biologic-associated lung function improvement may encourage earlier intervention in patients with impaired lung function or at risk of accelerated lung function decline.

Specific IgE Response and Omalizumab Responsiveness in Severe Allergic Asthma

Objective

Omalizumab has demonstrated clinical efficacy in patients with severe allergic asthma sensitized to perennial allergens and/or severe pollinosis through inhibition of IgE-dependent allergic response. When considering the "one airway, one disease" concept, sensitization to pollen could predict responsiveness to omalizumab. This study aimed to assess whether the pretreatment specific IgE response could be a predictor of responsiveness to omalizumab in severe allergic asthma sensitized to perennial allergens.

Methods

In this retrospective study, 41 adult patients with severe allergic asthma sensitized to perennial allergens (27 females; mean age 59 years) who had completed 52-week omalizumab treatment were enrolled. The Global Evaluation of Treatment Effectiveness was performed, and demographic characteristics and the positive ratios of specific IgE responses classified into five subgroups (pollen, dust mite, house dust, mold, and animal dander) were compared between responders and non-responders. Multivariate logistic regression analyses were performed to identify predictors of responsiveness to omalizumab.

Results

Thirty-one patients (76%) were identified as responders. The number of sensitized aeroallergen subgroups and sensitization to pollens were significantly higher in responders than in non-responders (both p<0.05). Multivariate logistic regression analysis showed that sensitization to pollen (OR = 8.41, p = 0.02) was independently associated with the effectiveness of omalizumab.

Conclusion

Pretreatment serum pollen-specific IgE could be a predictor of responsiveness to omalizumab.

Cumulative IgE-levels specific for respiratory allergens as biomarker to predict efficacy of anti-IgE-based treatment of severe asthma

Molecular therapies, including anti-IgE, biologicals and small molecules are increasingly used for treatment of asthma. The effectiveness of these therapies may be increased with biomarkers. Aim of this study was to assess the value of measuring cumulative IgE levels specific for respiratory allergens to increase the efficacy of anti-IgE therapy for severe bronchial asthma. One hundred and thirty seven patients with severe asthma were recruited from 2016 to 2022. Standard empirical allergy diagnosis (i.e., anamnesis, skin testing, allergen-specific IgE measurement), blood eosinophil counting, measurement of total IgE and of cumulative IgE-specific for respiratory allergens by Phadiatop™ were performed. Thirty four patients with severe allergic asthma, for whom all three diagnostic methods were performed, were then used to analyze the efficacy of anti-IgE treatment in patients stratified in two groups according to cumulative IgE levels specific for respiratory allergens determined by Phadiatop™. Group #1 patients (n = 8) had cumulative specific IgE values ≥ 0.35 and < 1.53 PAU/l while in group #2 patients (n = 26) they were ≥ 1.53 PAU/l. Treatment with Omalizumab was performed for at least 12 months. The level of asthma control (ACT questionnaire), the number of asthma exacerbations, the quality of life (AQLQ questionnaire), the need for systemic corticosteroids, and the respiratory function (FEV1) was determined by “before-after” analysis for each group, followed by a comparison of the dynamics between groups. In group 2 patients with an initial allergen-specific IgE level ≥ 1.53 kUA/L, the efficacy of Omalizumab treatment was better regarding asthma control, number of exacerbations, and quality of life than in group 1 patients. Our study provides evidence that measuring cumulative levels of IgE specific for respiratory allergens could be a useful screening method for detecting an allergic phenotype of severe asthma and may serve as biomarker to enhance the success of IgE-targeted therapy.

[Markers of severity and predictors of response to treatment in severe asthma]

Asthma is a multifactorial disease with complex pathophysiology. Knowledge of its immunopathology and inflammatory mechanisms is progressing and has led to the development over recent years of increasingly targeted therapeutic strategies. The objective of this review is to pinpoint the different predictive markers of asthma severity and therapeutic response. Obesity, nasal polyposis, gastroesophageal reflux disease and intolerance to aspirin have all been considered as clinical markers associated with asthma severity, as have functional markers such as bronchial obstruction, low FEV1, small daily variations in FEV1, and high FeNO. While sinonasal polyposis and allergic comorbidities are associated with better response to omalizumab, nasal polyposis or long-term systemic steroid use are associated with better response to antibodies targeting the IL5 pathway. Elevated total IgE concentrations and eosinophil counts are classic biological markers regularly found in severe asthma. Blood eosinophils are predictive biomarkers of response to anti-IgE, anti-IL5, anti-IL5R and anti-IL4R biotherapies. Dupilumab is particularly effective in a subgroup of patients with marked type 2 inflammation (long-term systemic corticosteroid therapy, eosinophilia≥150/μl or FENO>20 ppb). Chest imaging may help to identify severe patients by seeking out bronchial wall thickening and bronchial dilation. Study of the patient's environment is crucial insofar as exposure to tobacco, dust mites and molds, as well as outdoor and indoor air pollutants (cleaning products), can trigger asthma exacerbation. Wider and more systematic use of markers of severity or response to treatment could foster increasingly targeted and tailored approaches to severe asthma.

Allergic and eosinophilic asthma in the era of biomarkers and biologics: similarities, differences and misconceptions

OBJECTIVE

Severe asthma is associated with substantial personal and economic burden; maintaining disease control is the key management goal. Increased understanding of asthma heterogeneity and development of type 2 (T2)-targeting biologics has substantially advanced disease management and outcomes; however, despite both being driven by T2 inflammation, allergic and eosinophilic asthma have different treatment recommendations. We sought to better understand the similarities and differences between allergic and eosinophilic asthma and highlight where misconceptions may arise.

DATA SOURCES

Published articles, pivotal trials, post hoc analyses, and asthma clinical guidelines sourced from PubMed.

STUDY SELECTIONS

Sources reporting allergic and eosinophilic asthma classifications, disease mechanisms, and biomarkers associated with treatment response.

RESULTS

This review highlights that severe allergic and eosinophilic asthma are both driven by T2 inflammation with eosinophils playing a cardinal role. Despite this overlap, treatment recommendations differ based on asthma classification. T2 cytokine gene expression is a reasonably well-established research tool, but not a well-established biomarker in clinical practice, unlike blood eosinophil counts, fractional exhaled nitric oxide, and immunoglobulin E; the clinical relevance of immunoglobulin E as a predictive biomarker remains unclear.

CONCLUSION

Asthma classifications that can be easily characterized at patient level to ensure accurate diagnosis, predict disease trajectory, and treatment response are required. The current dichotomy of allergic and eosinophilic asthma classifications is likely too simplistic, given the similar eosinophil-mediated disease pathophysiology in both classifications. Our results provide future directions to guide clinically meaningful interpretation of asthma endophenotypes, which may improve understanding of severe asthma characterization and aid future advances in defining responders more precisely with personalized medicine approaches.

How to Choose the Correct Drug in Severe Pediatric Asthma

When a child with severe asthma (asthma defined clinically for the purposes of this review as wheeze, breathlessness, and chest tightness sometimes with cough) does not respond to treatment, it is important to be sure that an alternative or additional diagnosis is not being missed. In school age children, the next step is a detailed protocolized assessment to determine the nature of the problem, whether within the airway or related to co-morbidities or social/environmental factors, in order to personalize the treatment. For example, those with refractory difficult asthma due to persistent non-adherence may benefit from using budesonide and formoterol combined in a single inhaler [single maintenance and reliever treatment (SMART)] as both a reliever and preventer. For those with steroid-resistant Type 2 airway inflammation, the use of biologicals such as omalizumab and mepolizumab should be considered, but for mepolizumab at least, there is a paucity of pediatric data. Protocols are less well developed in preschool asthma, where steroid insensitive disease is much more common, but the use of two simple measurements, aeroallergen sensitization, and peripheral blood eosinophil count, allows the targeted use of inhaled corticosteroids (ICSs). There is also increasing evidence that chronic airway infection may be important in preschool wheeze, increasing the possibility that targeted antibiotics may be beneficial. Asthma in the first year of life is not driven by Type 2 inflammation, so beyond avoiding prescribing ICSs, no evidence based recommendations can be made. In the future, we urgently need to develop objective biomarkers, especially of risk, so that treatment can be targeted effectively; we need to address the scandal of the lack of data in children compared with adults, precluding making evidence-based therapeutic decisions and move from guiding treatment by phenotypes, which will change as the environment changes, to endotype based therapy.

Switch from Omalizumab to Benralizumab in Allergic Patients with Severe Eosinophilic Asthma: A Real-Life Experience from Southern Italy

Background. The wide availability of monoclonal antibodies for the add-on therapy of severe asthma currently allows for the personalization of biologic treatment by selecting the most appropriate drug for each patient. However, subjects with overlapping allergic and eosinophilic phenotypes can be often eligible to more than one biologic, so that the first pharmacologic choice can be quite challenging for clinicians. Within such a context, the aim of our real-life investigation was to verify whether allergic patients with severe eosinophilic asthma, not adequately controlled by an initial biologic treatment with omalizumab, could experience better therapeutic results from a pharmacologic shift to benralizumab. Patients and methods. Twenty allergic patients with severe eosinophilic asthma, unsuccessfully treated with omalizumab and then switched to benralizumab, were assessed for at least 1 year in order to detect eventual changes in disease exacerbations, symptom control, oral corticosteroid intake, lung function, and blood eosinophils. Results. In comparison to the previous omalizumab therapy, after 1 year of treatment with benralizumab our patients experienced significant improvements in asthma exacerbation rate (p < 0.01), rescue medication need (p < 0.001), asthma control test (ACT) score (p < 0.05), forced expiratory volume in the first second (FEV₁) (p < 0.05), and blood eosinophil count (p < 0.0001). Furthermore, with respect to the end of omalizumab treatment, the score of sino-nasal outcome test-22 (SNOT-22) significantly decreased after therapy with benralizumab (p < 0.05). Conclusion. The results of this real-life study suggest that the pharmacologic shift from omalizumab to benralizumab can be a valuable therapeutic approach for allergic patients with severe eosinophilic asthma, not adequately controlled by anti-IgE treatment.

Ethnic Differences in Severe Asthma Clinical Care and Outcomes: An Analysis of United Kingdom Primary and Specialist Care

BACKGROUND

Understanding the effects of ethnicity in severe asthma is important for optimal personalized patient care.

OBJECTIVE

To assess ethnic differences in disease control, exacerbations, biological phenotype, and treatment in severe asthma in the United Kingdom.

METHODS

We compared demographics, type 2 biomarkers, lung function, asthma control, medications, and health care use between White and underrepresented ethnic group patients in the UK Severe Asthma Registry (UKSAR) and Optimum Patient Care Research Database (OPCRD).

RESULTS

A total of 3637 patients (665 from the underrepresented ethnic group) were included from UKSAR and 10,549 (577 from the underrepresented ethnic group) from OPCRD. Patients in the underrepresented ethnic group had higher levels of uncontrolled disease when measurements were made using the asthma control questionnaire in UKSAR (odds ratio [OR] = 1.47; 95% confidence interval [CI], 1.12-1.93) and the Royal College of Physicians 3 Questions in OPCRD (OR = 1.82; 95% CI, 1.27-2.60). Although exacerbation rates were similar, patients in the underrepresented ethnic group were more likely to have recently attended the emergency department (OR = 1.55; 95% CI, 1.26-1.92) or to have been hospitalized (OR = 1.31; 95% CI, 1.07-1.59) owing to asthma. Inflammatory biomarkers were consistently higher in the underrepresented ethnic group, including blood eosinophils in OPCRD (ratio = 1.12; 95% CI, 1.05-1.20) and in UKSAR blood eosinophils (ratio = 1.16; 95% CI, 1.06-1.27), FeNO (ratio = 1.14; 95% CI, 1.04-1.26), and IgE (ratio = 1.70; 95% CI, 1.47-1.97). Patients in the underrepresented ethnic group were more likely to be atopic in the UKSAR (OR = 1.32; 95% CI, 1.07-1.63) and OPCRD (OR = 1.67; 95% CI, 1.26-2.21), and less likely to be using maintenance oral corticosteroids at referral (OR = 0.75; 95% CI, 0.61-0.92).

CONCLUSIONS

Severe asthma patients from underrepresented ethnic groups presented with a higher disease burden and were more likely to attend the emergency department. They had a distinct phenotypic presentation and differences in medicine use, with higher levels of type 2 biomarkers.

Recent Insights into the Management of Inflammation in Asthma

The present prevailing inflammatory paradigm in asthma is of T2-high inflammation orchestrated by key inflammatory cells like Type 2 helper lymphocytes, innate lymphoid cells group 2 and associated cytokines. Eosinophils are key components of this T2 inflammatory pathway and have become key therapeutic targets. Real-world evidence on the predominant T2-high nature of severe asthma is emerging. Various inflammatory biomarkers have been adopted in clinical practice to aid asthma characterization including airway measures such as bronchoscopic biopsy and lavage, induced sputum analysis, and fractional exhaled nitric oxide. Blood measures like eosinophil counts have also gained widespread usage and multicomponent algorithms combining different parameters are now appearing. There is also growing interest in potential future biomarkers including exhaled volatile organic compounds, micro RNAs and urinary biomarkers. Additionally, there is a growing realisation that asthma is a heterogeneous state with numerous phenotypes and associated treatable traits. These may show particular inflammatory patterns and merit-specific management approaches that could improve asthma patient outcomes. Inhaled corticosteroids (ICS) remain the mainstay of asthma management but their use earlier in the course of disease is being advocated. Recent evidence suggests potential roles for ICS in combination with long-acting beta-agonists (LABA) for as needed use in mild asthma whilst maintenance and reliever therapy regimes have gained widespread acceptance. Other anti-inflammatory strategies including ultra-fine particle ICS, leukotriene receptor antagonists and macrolide antibiotics may show efficacy in particular phenotypes too. Monoclonal antibody biologic therapies have recently entered clinical practice with significant impacts on asthma outcomes. Understanding of the efficacy and use of those agents is becoming clearer with a growing body of real-world evidence as is their potential applicability to other treatable comorbid traits. In conclusion, the evolving understanding of T2 driven inflammation alongside a treatable traits disease model is enhancing therapeutic approaches to address inflammation in asthma.

Switching from omalizumab to mepolizumab: real-life experience from Southern Italy

BACKGROUND

Current availability of several biologic treatments for severe asthma makes it possible to choose the most appropriate for each patient. Sometimes a good percentage of patients with severe asthma may be eligible for biologics that target either the allergic phenotype or the eosinophilic one, but not all respond to that selected as first choice. The aim of our real-life study was to assess whether, for patients with severe eosinophilic allergic asthma, not previously controlled by the anti-IgE omalizumab, the shift to another biologic targeting interleukin-5, such as mepolizumab, may represent a good therapeutic choice.

METHODS

A total of 41 consecutive patients with severe, persistent allergic, eosinophilic asthma, uncontrolled despite treatment with omalizumab, were enrolled in seven certified Clinical Respiratory Units of Southern Italy (Catania, Catanzaro, Foggia, Bari, Palermo, and two University Respiratory Units of Naples) and shifted to mepolizumab without a wash-out period. Data at baseline, after at least 12 months of therapy with omalizumab, and after at least 12 months of treatment with mepolizumab were collected.

RESULTS

After at least 12 months of therapy with mepolizumab, patients experienced a significant decrease in the number of exacerbations/year (5.8 ± 1.8 versus 0.7 ± 0.9, p < 0.0001), an increment of asthma control test score (12 ± 2.7 versus 21.9 ± 2.7, p < 0.0001), an increase in pre-bronchodilator forced expiratory volume in 1 s (1.56 ± 0.45 l versus 1.86 ± 0.52 l, p < 0.0001), and a reduction of blood eosinophils (584 ± 196 cells/µl versus 82 ± 56 cells/µl, p < 0.0001). The percentage of patients who were dependent on corticosteroids significantly decreased from 46% at baseline to 5% during treatment with mepolizumab.

CONCLUSION

Results of our real-life multicentric experience confirms that the shift to mepolizumab could be a good therapeutic strategy in severe eosinophilic allergic asthma not previously controlled by omalizumab. The reviews of this paper are available via the supplemental material section.

Clinical Determinants of Successful Omalizumab Therapy in Severe Allergic Asthma Patients: 4-Year-Long, Real-Life Observation

Introduction

Omalizumab is a high-cost therapy recommended for the treatment of severe allergic asthma.

Objective

To find clinical parameters that are related to the sustained response to omalizumab.

Patients and Methods

This retrospective, real-life, 4-year follow-up was provided in Poland between March 2013 and May 2019. The success of omalizumab was assessed based on composed subjective and objective criteria. Simple/multiple regression analyses were performed to search for predictors of the response to omalizumab.

Results

A total of 989 severe allergic asthma patients were referred for omalizumab therapy, of whom 854 patients were considered eligible for treatment. At weeks 16 and 52, omalizumab was successful in 84% and 91% of patients, respectively. Treatment effectiveness was maintained up to the 4-year follow-up. Four predictors of the response to omalizumab were found at week 16 and two at week 52. The results at week 16 may be used as predictors of success at week 52 based on the model including baseline FEV1% and change in ACQ-7 and miniAQLQ score at week 16: the area under the ROC curve equals 0.746 [95% CI: 0.672–0.820].

Conclusion

Omalizumab therapy is very effective, with this efficacy sustained after 4 years of treatment. Success of the therapy can be predicted from the baseline FEV1% and clinical improvement (based on ACQ-7 and miniAQLQ scores) at week 16.

Whole blood transcriptional variations between responders and non-responders in asthma patients receiving omalizumab

BACKGROUND

Anti-IgE (omalizumab) has been used for the treatment of moderate-to-severe asthma that is not controlled by inhaled steroids. Despite its success, it does not always provide patients with significant clinical benefits.

OBJECTIVE

To investigate the transcriptional variations between omalizumab responders and non-responders and to study the mechanisms of action of omalizumab.

METHODS

The whole blood transcriptomes of moderate-to-severe adult asthma patients (N = 45:34 responders and 11 non-responders) were analysed over the course of omalizumab treatment. Non-asthmatic healthy controls (N = 17) were used as controls.

RESULTS

Transcriptome variations between responders and non-responders were identified using the genes significant (FDR < 0.05) in at least one comparison of each patient response status and time point compared with control subjects. Using gene ontology and network analysis, eight clusters of genes were identified. Longitudinal analyses of individual clusters revealed that responders could maintain changes induced with omalizumab treatment and become more similar to the control subjects, while non-responders tend to remain more similar to their pre-treatment baseline. Further analysis of an inflammatory gene cluster revealed that genes associated with neutrophil/eosinophil activities were up-regulated in non-responders and, more importantly, omalizumab did not significantly alter their expression levels. The application of modular analysis supported our findings and further revealed variations between responders and non-responders.

CONCLUSION AND CLINICAL RELEVANCE

This study provides not only transcriptional variations between omalizumab responders and non-responders, but also molecular insights for controlling asthma by omalizumab.

Minimal clinically important difference for asthma endpoints: an expert consensus report

Minimal clinically important difference (MCID) can be defined as the smallest change or difference in an outcome measure that is perceived as beneficial and would lead to a change in the patient's medical management.

The aim of the current expert consensus report is to provide a “state-of-the-art” review of the currently available literature evidence about MCID for end-points to monitor asthma control, in order to facilitate optimal disease management and identify unmet needs in the field to guide future research.

A series of MCID cut-offs are currently available in literature and validated among populations of asthmatic patients, with most of the evidence focusing on outcomes as patient reported outcomes, lung function and exercise tolerance. On the contrary, only scant and partial data are available for inflammatory biomarkers. These clearly represent the most interesting target for future development in diagnosis and clinical management of asthma, particularly in view of the several biologic drugs in the pipeline, for which regulatory agencies will soon require personalised proof of efficacy and treatment response predictors.

Minimal clinically important difference (MCID) cut-offs in asthma are validated for patient reported outcomes and lung function, but not for inflammatory biomarkers. MCID represents a key target for future development in asthma management. http://bit.ly/33hcWIe

Pediatric use of omalizumab for allergic asthma

INTRODUCTION

Severe pediatric asthma is associated with significant morbidity as well as with a high economic burden. It represents a heterogeneous disease with multiple clinical phenotypes. Currently, physicians are facing the challenge to provide a 'personalized medicine approach', which is tailored to the diverse pathomechanisms underlying clinical presentations. Three main endotypes of airway inflammation have been described in children with severe asthma. While neutrophilic and paucigranulocytic inflammatory patterns are quite uncommon in childhood, type Th2 inflammation asthma with elevated IgE is the most prevalent in pediatric asthma. Considering the pivotal role of IgE in type Th2 inflammation asthma, the blockade of IgE using anti-IgE therapy represents a potent therapeutic option for severe pediatric asthma in children.

AREAS COVERED

This review aims to focus on the role of omalizumab as a treatment option in pediatric patients (aged six years and above) with severe allergic asthma.

EXPERT OPINION

The clinical efficacy and safety of omalizumab for the treatment of pediatric asthma is well documented in clinical trials and observational studies. Further studies are still required to characterize the potential benefit of anti-IgE therapy in airway remodeling, identify additional biomarkers of clinical response and address current unmet needs, including the limit on omalizumab use in children younger than six years.

Defining severe obstructive lung disease in the biologic era: an endotype-based approach

Severe obstructive lung disease, which encompasses asthma, chronic obstructive pulmonary disease (COPD) or features of both, remains a considerable global health problem and burden on healthcare resources. However, the clinical definitions of severe asthma and COPD do not reflect the heterogeneity within these diagnoses or the potential for overlap between them, which may lead to inappropriate treatment decisions. Furthermore, most studies exclude patients with diagnoses of both asthma and COPD. Clinical definitions can influence clinical trial design and are both influenced by, and influence, regulatory indications and treatment recommendations. Therefore, to ensure its relevance in the era of targeted biologic therapies, the definition of severe obstructive lung disease must be updated so that it includes all patients who could benefit from novel treatments and for whom associated costs are justified. Here, we review evolving clinical definitions of severe obstructive lung disease and evaluate how these have influenced trial design by summarising eligibility criteria and primary outcomes of phase III randomised controlled trials of biologic therapies. Based on our findings, we discuss the advantages of a phenotype- and endotype-based approach to select appropriate populations for future trials that may influence regulatory approvals and clinical practice, allowing targeted biologic therapies to benefit a greater proportion and range of patients. This calls for co-ordinated efforts between investigators, pharmaceutical developers and regulators to ensure biologic therapies reach their full potential in the management of severe obstructive lung disease.

Clinical Efficacy and Safety of Omalizumab in the Treatment of Allergic Rhinitis: A Systematic Review and Meta-analysis of Randomized Clinical Trials

Background

Patients with moderate to severe allergic rhinitis (AR) who are treated according to the current rhinitis management guidelines may be inadequately controlled. These patients are at risk of serious comorbidities, such as asthma and chronic sinusitis. These symptoms, sneezing and an itchy, runny, stuffy nose, may have a negative impact on patients’ daily functioning. Omalizumab is being developed as a new choice for the treatment of AR. We therefore undertook a meta-analysis to assess the efficacy and safety of omalizumab in the treatment of AR.

Methods

We systematically searched PubMed, Cochrane Library, and MEDLINE databases for randomized controlled studies on the treatment of AR with omalizumab. Our evaluation outcomes were symptom scores, medication efficacy, combined symptom and medication scores, and adverse events. We descriptively summarized and quantitatively synthesized original data to evaluate the efficacy and safety of omalizumab in the treatment of AR by using Stata12.0 software for meta-analyses.

Results

The results of our meta-analysis showed that there were statistically significant differences between the omalizumab group and the control group in the following aspects: daily nasal symptom score (standardized mean difference [SMD] = –0.443, 95% confidence interval [CI]: –0.538 to –0.347, P < .001); daily ocular symptom score (SMD = –0.385, 95% CI: –0.5 to –0.269, P < .001); daily nasal medication symptom scores (SMD = –0.421, 95% CI: –0.591 to –0.251, P < .001); proportion of days of emergency drug use (risk ratio [RR] = 0.488, 95% CI: 0.307 to 0.788, P < .005); rhinoconjunctivitis-specific quality of life questionnaire (SMD = –0.286, 95% CI: –0.418 to –0.154, P < .001); and overall evaluation (RR = 1.435, 95% CI: 1.303–1.582, P < .001). There was no statistically significant difference in safety indicator: adverse events (RR = 1.026, 95% CI: 0.916–1.150, P = .655).

Conclusion

Omalizumab is effective and relatively safe in patients with AR; omalizumab used in conjunction with special immunotherapy has shown promising results, especially in reducing adverse events.

Severe asthma phenotypes in patients controlled with omalizumab: A real-world study

BACKGROUND

The appropriate identification of asthma phenotypes of responders to omalizumab would optimize the selection of treatment.

OBJECTIVE

To describe the most frequent clinical phenotypes in patients with severe asthma responding to omalizumab and their clinical and pulmonary function improvement.

METHODS

This was an observational, retrospective, multicenter study. Adult patients with severe asthma, who achieved good control after the first year of treatment with omalizumab were included. Omalizumab was prescribed according to clinical routine practice. Responders were assigned to one pre-established phenotype based on the most predominant one before they had started treatment with omalizumab, all according to the physician's criteria. Data about asthma symptoms, number of non-severe asthma exacerbations, medication intake (inhaled and oral corticosteroids and rescue medication), lung function, high fractional exhaled nitric oxide (FeNO) and peripheral eosinophils counts were recorded.

RESULTS

Among the 345 patients included, the main phenotypes were severe asthma with frequent exacerbations (29.9%), early-onset allergic asthma (23.8%), severe steroid-dependent asthma (18.8%), and severe eosinophilic asthma (13.6%). Clinical and respiratory changes observed after first year of treatment with omalizumab included: reduction in asthma symptoms, reduction in the use and dose of corticosteroids and need for rescue therapy, improvement of pulmonary function, reduction in the number of episodes of non-severe asthma exacerbations regardless of the duration of severe disease since the diagnosis. Increased blood levels of peripheral eosinophils and high FeNO levels were found at baseline.

CONCLUSION

Several heterogeneous severe asthma phenotypes were observed as good responders to omalizumab.

Toward clinically applicable biomarkers for asthma: An EAACI position paper

Inflammation, structural, and functional abnormalities within the airways are key features of asthma. Although these processes are well documented, their expression varies across the heterogeneous spectrum of asthma. Type 2 inflammatory responses are characterized by increased levels of eosinophils, FeNO, and type 2 cytokines in blood and/or airways. Presently, type 2 asthma is the best-defined endotype, typically found in patients with allergic asthma, but surprisingly also in nonallergic patients with (severe) asthma. The etiology of asthma with non-type 2 inflammation is less clear. During the past decade, targeted therapies, including biologicals and small molecules, have been increasingly integrated into treatment strategies of severe asthma. These treatments block specific inflammatory pathways or single mediators. Single or composite biomarkers help to identify patients who will benefit from these treatments. So far, only a few inflammatory biomarkers have been validated for clinical application. The European Academy of Allergy & Clinical Immunology Task Force on Biomarkers in Asthma was initiated to review different biomarker sampling methods and to investigate clinical applicability of new and existing inflammatory biomarkers (point-of-care) to support diagnosis, targeted treatment, and monitoring of severe asthma. Subsequently, we discuss existing and novel targeted therapies for asthma as well as applicable biomarkers.

Effect of mepolizumab in severe eosinophilic asthma according to omalizumab eligibility

BACKGROUND

Patients with severe asthma can present with overlapping eosinophilic and allergic phenotypes, which makes it challenging when deciding which biologic therapy is most appropriate to reduce exacerbations and help achieve asthma control.

OBJECTIVE

This post hoc meta-analysis evaluated the efficacy of the licensed dose of mepolizumab (100 mg administered subcutaneously [SC]) versus placebo in patients with severe eosinophilic asthma (SEA), according to omalizumab eligibility and associated allergic characteristics.

METHODS

Data from two Phase 3 studies (MENSA [MEA115588/NCT01691521]; MUSCA [200862/NCT02281318]) were analyzed. Patients ≥12 years of age with SEA who experienced ≥2 exacerbations in the previous year received placebo, mepolizumab 100 mg SC or 75 mg intravenously, plus standard of care (high-dose inhaled corticosteroids and other controllers), every 4 weeks. Data from patients who received ≥1 dose placebo or mepolizumab 100 mg SC were used for this analysis. The primary endpoint was the rate of clinically significant exacerbations; other outcomes included forced expiratory volume in 1 s (FEV₁), Asthma Control Questionnaire (ACQ-5) score and quality of life measured using St George's Respiratory Questionnaire (SGRQ).

RESULTS

Rate reductions in clinically significant exacerbations with mepolizumab versus placebo were similar in omalizumab eligible and ineligible patients (57% vs 55%). FEV₁, ACQ-5 and SGRQ scores improved with mepolizumab versus placebo regardless of omalizumab eligibility, Immunoglobulin E levels, or atopic status.

CONCLUSION

This analysis indicated that mepolizumab 100 mg SC has clinical benefit in patients with blood eosinophil counts ≥150 cells/μL (or history of ≥300 cells/μL), regardless of allergic characteristics or omalizumab eligibility.

Characterization of tenascin-C as a novel biomarker for asthma: utility of tenascin-C in combination with periostin or immunoglobulin E

Background

Extracellular matrix proteins tenascin-C (TNC) and periostin, which were identified as T-helper cell type 2 cytokine-induced genes in human bronchial epithelial cells, accumulate in the airway basement membrane of asthmatic patients. Although serum periostin has been accepted as a type 2 biomarker, serum TNC has not been evaluated as a systemic biomarker in asthma. Therefore, the objective of this study was to evaluate whether serum TNC can serve as a novel biomarker for asthma.

Methods

We evaluated 126 adult patients with mild to severe asthma. Serum TNC, periostin, and total IgE concentrations were quantified using enzyme-linked immunosorbent assays.

Results

Serum TNC levels were significantly higher in patients with severe asthma and high serum total IgE levels. Patients with both high serum TNC (> 37.16 ng/mL) and high serum periostin (> 95 ng/mL) levels (n = 20) or patients with both high serum TNC and high serum total IgE (> 100 IU/mL) levels (n = 36) presented higher disease severity and more severe airflow limitation than patients in other subpopulations.

Conclusions

To our knowledge, this is the first study to show that serum TNC levels in asthmatic patients are associated with clinical features of asthma and that the combination of serum TNC and periostin levels or combination of serum TNC and total IgE levels were more useful for asthma than each single marker, suggesting that serum TNC can serve as a novel biomarker for asthma.

Electronic supplementary material

The online version of this article (10.1186/s13223-018-0300-7) contains supplementary material, which is available to authorized users.

Biomarkers for severe allergic asthma in children: could they be useful to guide disease control and use of omalizumab?

INTRODUCTION

Although symptom controls in asthmatic children can be achieved through compliant use of conventional medication, some children have uncontrolled severe persistent asthma, especially if they are allergic. For these children, omalizumab (approved by the EMA and FDA in children aged > 6 years) could be a therapeutic option. However, response to omalizumab varies from one child to another. Predictive biomarkers of omalizumab effectiveness could be useful to monitor response to treatment. Area covered: The authors searched in the PubMed database for publications related to the use of biomarkers in allergic asthma. Supported by their own experience in phenotyping asthma in children, they analyzed whether these biomarkers could be useful in assessing response to omalizumab. Expert commentary: Th2 inflammation in children with allergic asthma can be assessed by measuring several biomarkers (blood eosinophil, serum ECP or periostin, FeNO). While a single measurement may be insufficient, a combination of biomarkers assessments may improve the follow-up of children treated by omalizumab.

New and emerging drug treatments for severe asthma

Asthma is a common chronic inflammatory condition of the airways affecting over 300 million people world-wide. In 5%-10% of cases, it is severe, with disproportionate healthcare resource utilization including costs associated with frequent exacerbations and the long-term health effects of systemic steroids. Characterization of inflammatory pathways in severe asthma has led to the development of targeted biological and small molecule therapies which aim to achieve disease control while minimizing corticosteroid-associated morbidity. Herein, we review currently licensed agents and those in development, and speculate how drug therapy for severe asthma might evolve and impact on clinical outcomes in the near future.

Biomarkers for severe eosinophilic asthma

The last decade has seen the approval of several new biologics for the treatment of severe asthma-targeting specific endotypes and phenotypes. This review will examine how evidence generated from the mepolizumab clinical development program showed that blood eosinophil counts, rather than sputum or tissue eosinophil counts, evolved as a pharmacodynamic and predictive biomarker for the efficacy of treatment with mepolizumab in patients with severe eosinophilic asthma. Based on the available evidence and combined with clinical judgement, a baseline blood eosinophil threshold of 150 cells/μL or greater or a historical blood eosinophil threshold of 300 cells/μL or greater will allow selection of patients with severe eosinophilic asthma who are most likely to achieve clinically significant reductions in the rate of exacerbations with mepolizumab treatment.

The current and future role of biomarkers in type 2 cytokine-mediated asthma management

Assessment and management of asthma is complicated by the heterogeneous pathophysiological mechanisms that underlie its clinical presentation, which are not necessarily reflected in standardized management paradigms and which necessitate an individualized approach to treatment. This is particularly important with the emerging availability of a variety of targeted forms of therapy that may only be appropriate for use in particular patient subgroups. The identification of biomarkers can potentially aid diagnosis and inform prognosis, help guide treatment decisions and allow clinicians to predict and monitor response to treatment. Biomarkers for asthma have been identified from a variety of sources, including airway, exhaled breath and blood. Biomarkers from exhaled breath include fractional exhaled nitric oxide, measurement of which can help identify patients most likely to benefit from inhaled corticosteroids and targeted anti-immunoglobulin E therapy. Biomarkers measured in blood are relatively non-invasive and technically more straightforward than those measured from exhaled breath or directly from the airway. The most well established of these are the blood eosinophil count and serum periostin, both of which have demonstrated utility in identifying patients most likely to benefit from targeted anti-interleukin and anti-immunoglobulin E therapies, and in monitoring subsequent treatment response. For example, serum periostin appears to be a biomarker for responsiveness to inhaled corticosteroid therapy and may help identify patients as suitable candidates for anti-IL-13 treatment. The use of biomarkers can therefore potentially help avoid unnecessary morbidity from high-dose corticosteroid therapy and allow the most appropriate and cost-effective use of targeted therapies. Ongoing clinical trials are helping to further elucidate the role of established biomarkers in routine clinical practice, and a range of other circulating novel potential biomarkers are currently being investigated in the research setting.

New approaches for identifying and testing potential new anti-asthma agents

INTRODUCTION

Asthma is a chronic disease with significant heterogeneity in clinical features, disease severity, pattern of underlying disease mechanisms, and responsiveness to specific treatments. While the majority of asthmatic patients are controlled by standard pharmacological strategies, a significant subgroup has limited therapeutic options representing a major unmet need. Ongoing asthma research aims to better characterize distinct clinical phenotypes, molecular endotypes, associated reliable biomarkers, and also to develop a series of new effective targeted treatment modalities. Areas covered: The expanding knowledge on the pathogenetic mechanisms of asthma has allowed researchers to investigate a range of new treatment options matched to patient profiles. The aim of this review is to provide a comprehensive and updated overview of the currently available, new and developing approaches for identifying and testing potential treatment options for asthma management. Expert opinion: Future therapeutic strategies for asthma require the identification of reliable biomarkers that can help with diagnosis and endotyping, in order to determine the most effective drug for the right patient phenotype. Furthermore, in addition to the identification of clinical and inflammatory phenotypes, it is expected that a better understanding of the mechanisms of airway remodeling will likely optimize asthma targeted treatment.

Biologic therapy in the management of asthma

PURPOSE OF REVIEW

Current asthma management relies on inhaled corticosteroids, but some asthma is not well controlled with inhaled steroids alone or in combination with long-acting bronchodilators or leukotriene pathway inhibitors. The field of biologic therapy has grown dramatically in the past two decades, with current availability of three molecules, with two distinct and highly selective approaches to interfering with the allergic and eosinophilic airway inflammation common to most asthma. This review summarizes current and future options for incorporating biologic therapy into the overall management of asthma.

RECENT FINDINGS

Two new biologic agents have been recently introduced in the United States market, supported by well controlled, randomized clinical trials. These trials have provided insight into the types of patients who are most likely to benefit from these novel agents.

SUMMARY

In asthma patients with frequent exacerbations, the addition of a biologic agent targeting the interleukin-5 pathway, or immunoglobulin E, can significantly reduce exacerbations and improve asthma control. The clinical predictors of utility of specific agents overlap with one another, highlighting the importance of clinical judgment in the overall management of this complex disorder.

IgE and eosinophils as therapeutic targets in asthma

PURPOSE OF REVIEW

Asthma is a chronic inflammatory disorder characterized by reversible airflow obstruction, which is being more widely recognized as a broad-spectrum disease that encompasses multiple patient characteristics and pathophysiologic mechanisms. Suboptimal asthma control leads to increasing burden of healthcare costs and loss of productivity to society. Biologic therapies targeted at IgE and eosinophils can be used in poorly controlled allergic and eosinophilic asthma, respectively. The purpose of this review is to analyze the advancements in currently available biologic therapies targeted at IgE and eosinophils in asthma and to identify how these therapies may impact overall healthcare costs.

RECENT FINDINGS

Omalizumab is an anti-IgE antibody that is approved for use of poorly controlled moderate-to-severe asthma. Many studies have confirmed that omalizumab not only improves quality of life and symptom scores, but also decreases urgent care and emergency department visits and hospitalizations. Dupilumab is a biologic agent targeted at TH2 cytokines, but indirectly impacts IgE and is an important biologic agent for atopic disease. Mepolizumab, reslizumab, and benralizumab target IL-5, a key cytokine for eosinophils. For patients with poorly controlled eosinophilic asthma, these biologic agents improve asthma symptoms, reduce exacerbations, and reduce emergency visits and hospitalizations.

SUMMARY

Poorly controlled severe asthma affects a small portion of patients with asthma in the United States and yet it accounts for large portion of healthcare utilization. Biological therapies in poorly controlled severe persistent asthma have been identified to reduce healthcare utilization, including emergency visits and hospitalizations. Biologic agents have a clear beneficial role in the management of severe asthma, and further evaluations should be continued in identifying optimal patient characteristics for the various agents and overall benefit toward healthcare utilization and cost.

House Dust Mite Allergens: New Discoveries and Relevance to the Allergic Patient

PURPOSE OF REVIEW

Recent findings on house dust allergens and their contribution to knowledge that will significantly impact on current and future allergy treatments are appraised.

RECENT FINDINGS

Quantitation of IgE binding to a spectrum of allergen components in several independent studies in varying locations has largely affirmed the main components as the groups 1 and 2 and possibly 23 allergens with mid-tier contributions from the groups 4, 5, 7, and 21. Prevalent binding to Der p 23 has been recapitulated sometimes with low titers. The IgE of non-asthmatic atopic subjects binds at lower titer and to fewer components than that of asthmatics, and their IgG binding relative to IgE is higher especially for children hospitalized for exacerbation. The higher IgG ratios were associated with increased IL-10 a cytokine more readily induced from T cells of allergic subjects. Peptides representing the groups 1 and 2 allergens can be used to stimulate ex vivo T cells showing responses correlating with IgE binding and providing a valuable tool for ascertaining the contribution of IgE and T cells to disease. Also, the induction of Th2 and follicular helper T cells are shown to make different contributions in mice. Cross-reactivity of IgE binding assays with high-titer cross-reactive antibodies induced by scabies is a problem in the many areas of the world where scabies is highly prevalent and endemic and from recent increases in immigration. In the last few years, allergen research has produced results that warrant rapid translation into diagnostic tools and the formulation of allergen components for immunotherapy.

Treatment response with mepolizumab in severe eosinophilic asthma patients with previous omalizumab treatment

Background

We performed post hoc analyses to evaluate the effect of humanized monoclonal antibody mepolizumab in patients with severe eosinophilic asthma previously treated with omalizumab.

Methods

Data were collected from two randomized double‐blind, placebo‐controlled studies: MENSA (NCT01691521: 32‐week treatment phase) and SIRIUS (NCT01691508: 24‐week treatment phase). Active treatment was 75 mg intravenous mepolizumab (MENSA) or 100 mg subcutaneous mepolizumab (MENSA, SIRIUS). Patients had evidence of eosinophilic inflammation ≥150 cells/μl (at screening) or ≥300 cells/μl (during the previous year). Primary outcomes were the rate of exacerbations (MENSA) and the percentage reduction in oral corticosteroid (OCS) dose (SIRIUS). Other outcomes included lung function (forced expiratory volume in 1 s and morning peak expiratory flow), Asthma Control Questionnaire (ACQ‐5), St George's Respiratory Questionnaire (SGRQ) scores, and safety.

Results

Overall, 576 patients were included from MENSA and 135 from SIRIUS, with 13% and 33% previously receiving omalizumab, respectively. In MENSA, mepolizumab reduced the rate of exacerbations by 57% (prior omalizumab) and 47% (no prior omalizumab) vs placebo. In SIRIUS, reductions in OCS use were comparable regardless of prior omalizumab use. Despite reducing chronic OCS use, mepolizumab also resulted in similar reductions in exacerbation rate relative to placebo in both subgroups. Asthma control and quality of life improved with mepolizumab vs placebo in both studies independent of prior omalizumab use, as shown by ACQ‐5 and SGRQ scores. Adverse events were also comparable irrespective of prior omalizumab use.

Conclusions

These post hoc analyses indicate that patients with severe eosinophilic asthma respond positively to mepolizumab regardless of prior use of omalizumab.

Mepolizumab for severe refractory eosinophilic asthma: evidence to date and clinical potential

Severe asthma is characterized by major impairment of quality of life, poor symptom control and frequent exacerbations. Inflammatory, clinical and causative factors identify different phenotypes and endotypes of asthma. In the last few years, new treatment options have allowed for targeted treatments according to the different phenotypes of the disease. To accurately select a specific treatment for each asthmatic variant, the identification of appropriate biomarkers is required. Eosinophilic asthma is a distinct phenotype characterized by thickening of the basement membrane and corticosteroid responsiveness. This review reports the latest evidence on an anti-IL-5 monoclonal antibody, mepolizumab, a new and promising biological agent recently approved by the FDA specifically for the treatment of severe eosinophilic refractory asthma.

Role of T2 inflammation biomarkers in severe asthma

PURPOSE OF REVIEW

Severe asthma is a heterogeneous syndrome. Classification of asthma into phenotypes and endotypes can improve understanding and treatment of the disease. Identification and utilization of biomarkers, particularly those linked to T2 inflammation, can help group patients into phenotypes, predict those who will respond to a specific therapy, and assess the response to treatment.

RECENT FINDINGS

Biomarkers are present in sputum, exhaled breath, and blood of patients with asthma. These include sputum eosinophils and neutrophils, fractional excretion of nitric oxide, blood eosinophilia, IgE, and periostin. Many of these biomarkers are associated with eosinophilic inflammation propagated mainly by T2 cytokines such as IL-5 and IL-13, which are released from Th2 cells and Type 2 innate lymphoid cells. Biomarkers have been utilized in recent trials of novel biologic agents targeted at T2 inflammation and may contribute to the defining population who would respond to these therapies.

SUMMARY

Despite advances in the identification and utilization of asthma biomarkers, further studies are needed to better clarify the role of biomarkers, individually or in combination, in the diagnosis and treatment of severe asthma. Future therapeutic trials should include the use of biomarkers in their design, which may lead to a more personalized approach to therapy and improved outcomes.

[Omalizumab: What have we learned after ten years of prescription?]

INTRODUCTION

Omalizumab, an anti-immunoglobulin E monoclonal antibody, has now been used for ten years as an add-on therapy for severe adult atopic asthma, poorly controlled by high-doses inhaled steroids and long-acting beta-agonists.

BACKGROUND

This innovative therapy has been the first biotherapy used on a large scale in severe asthma. It has shown clinical benefits, especially in the prevention of severe exacerbation, with a satisfactory safety profile. Despite its cost, it is an interesting alternative to continuous oral steroids, which cause more long-term side effects.

PERSPECTIVES

After ten-years of prescription of omalizumab, we review here the mechanism of action, the benefits, the main side effects, the cost-effectiveness and also the alternative indications of this interesting molecule. We also consider the practicalities of using omalizumab, particularly the importance a rigorous assessment of its efficacy after 16 weeks of treatment, and possible future therapeutic indications.

CONCLUSION

Omalizumab has proven its efficacy in large randomized studies but also in real life practice in severe allergic asthma.

Pediatric asthma: guidelines-based care, omalizumab, and other potential biologic agents

Over the past several decades, the evidence supporting rational pediatric asthma management has grown considerably. As more is learned about the various phenotypes of asthma, the complexity of management will continue to grow. This article focuses on the evidence supporting the current guidelines-based pediatric asthma management and explores the future of asthma management with respect to phenotypic heterogeneity and biologics.

A novel IgE-neutralizing antibody for the treatment of severe uncontrolled asthma

The critical role played by IgE in allergic asthma is well-documented and clinically precedented, but some patients in whom IgE neutralization may still offer clinical benefit are excluded from treatment with the existing anti-IgE therapy, omalizumab, due to high total IgE levels or body mass. In this study, we sought to generate a novel high affinity anti-IgE antibody (MEDI4212) with potential to treat a broad severe asthma patient population. Analysis of body mass, total and allergen-specific IgE levels in a cohort of severe asthmatics was used to support the rationale for development of a high affinity IgE-targeted antibody therapeutic. Phage display technology was used to generate a human IgG1 lead antibody, MEDI4212, which was characterized in vitro using binding, signaling and functional assay systems. Protein crystallography was used to determine the details of the interaction between MEDI4212 and IgE. MEDI4212 bound human IgE with an affinity of 1.95 pM and was shown to target critical residues in the IgE Cε3 domain critical for interaction with FcεRI. MEDI4212 potently inhibited responses through FcεRI and also prevented the binding of IgE to CD23. When used ex vivo at identical concentration, MEDI4212 depleted free-IgE from human sera to levels ~1 log lower than omalizumab. Our results thus indicate that MEDI4212 is a novel, high affinity antibody that binds specifically to IgE and prevents IgE binding to its receptors. MEDI4212 effectively depleted free-IgE from human sera ex vivo to a level (1 IU/mL) anticipated to provide optimal IgE suppression in severe asthma patients.

Omalizumab for asthma in adults and children

BACKGROUND

Asthma is a respiratory (airway) condition that affects an estimated 300 million people worldwide and is associated with significant morbidity and mortality. Omalizumab is a monoclonal antibody that binds and inhibits free serum immunoglobulin E (IgE). It is called an 'anti-IgE' drug. IgE is an immune mediator involved in clinical manifestations of asthma. A recent update of National Institute for Health and Care Excellence (NICE) guidance in 2013 recommends omalizumab for use as add-on therapy in adults and children over six years of age with inadequately controlled severe persistent allergic IgE-mediated asthma who require continuous or frequent treatment with oral corticosteroids.

OBJECTIVES

To assess the effects of omalizumab versus placebo or conventional therapy for asthma in adults and children.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of trials for potentially relevant studies. The most recent search was performed in June 2013. We also checked the reference lists of included trials and searched online trial registries and drug company websites.

SELECTION CRITERIA

Randomised controlled trials examining anti-IgE administered in any manner for any duration. Trials with co-interventions were included, as long as they were the same in each arm.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study quality and extracted and entered data. Three modes of administration were identified from the published literature: inhaled, intravenous and subcutaneous injection. The main focus of the updated review is subcutaneous administration, as this route is currently used in clinical practice. Subgroup analysis was performed by asthma severity. Data were extracted from published and unpublished sources.

MAIN RESULTS

In all, 25 trials were included in the review, including 11 new studies since the last update, for a total of 19 that considered the efficacy of subcutaneous anti-IgE treatment as an adjunct to treatment with corticosteroids.For participants with moderate or severe asthma who were receiving background inhaled corticosteroid steroid (ICS) therapy, a significant advantage favoured subcutaneous omalizumab with regard to experiencing an asthma exacerbation (odds ratio (OR) 0.55, 95% confidence interval (CI) 0.42 to 0.60; ten studies, 3261 participants). This represents an absolute reduction from 26% for participants suffering an exacerbation on placebo to 16% on omalizumab, over 16 to 60 weeks. A significant benefit was noted for subcutaneous omalizumab versus placebo with regard to reducing hospitalisations (OR 0.16, 95% CI 0.06 to 0.42; four studies, 1824 participants), representing an absolute reduction in risk from 3% with placebo to 0.5% with omalizumab over 28 to 60 weeks. No separate data on hospitalisations were available for the severe asthma subgroup, and all of these data were reported for participants with the diagnosis of moderate to severe asthma. Participants treated with subcutaneous omalizumab were also significantly more likely to be able to withdraw their ICS completely than those treated with placebo (OR 2.50, 95% CI 2.00 to 3.13), and a small but statistically significant reduction in daily inhaled steroid dose was reported for omalizumab-treated participants compared with those given placebo (weighted mean difference (WMD) -118 mcg beclomethasone dipropionate (BDP) equivalent per day, 95% CI -154 to -84). However, no significant difference between omalizumab and placebo treatment groups was seen in the number of participants who were able to withdraw from oral corticosteroid (OCS) therapy (OR 1.18, 95% CI 0.53 to 2.63).Participants treated with subcutaneous omalizumab as an adjunct to treatment with corticosteroids required a small but significant reduction in rescue beta2-agonist medication compared with placebo (mean difference (MD) -0.39 puffs per day, 95% CI -0.55 to -0.24; nine studies, 3524 participants). This benefit was observed in both the moderate to severe (MD -0.58, 95% CI -0.84 to -0.31) and severe (MD -0.30, 95% CI -0.49 to -0.10) asthma subgroups on a background therapy of inhaled corticosteroids; however, no significant difference between subcutaneous omalizumab and placebo was noted for this outcome in participants with severe asthma who were receiving a background therapy of inhaled plus oral corticosteroids. Significantly fewer serious adverse events were reported in participants assigned to subcutaneous omalizumab than in those receiving placebo (OR 0.72, 95% CI 0.57 to 0.91; 15 studies, 5713 participants), but more injection site reactions were observed (from 5.6% with placebo to 9.1% with omalizumab).To reflect current clinical practice, discussion of the results is limited to subcutaneous use, and trials involving intravenous and inhaled routes have been archived.

AUTHORS' CONCLUSIONS

Omalizumab was effective in reducing asthma exacerbations and hospitalisations as an adjunctive therapy to inhaled steroids and during steroid tapering phases of clinical trials. Omalizumab was significantly more effective than placebo in increasing the numbers of participants who were able to reduce or withdraw their inhaled steroids. Omalizumab was generally well tolerated, although more injection site reactions were seen with omalizumab. Further assessment in paediatric populations is necessary, as is direct double-dummy comparison with ICS. Although subgroup analyses suggest that participants receiving prednisolone had better asthma control when they received omalizumab, it remains to be tested prospectively whether the addition of omalizumab has a prednisolone-sparing effect. It is also not clear whether there is a threshold level of baseline serum IgE for optimum efficacy of omalizumab. Given the high cost of the drug, identification of biomarkers predictive of response is of major importance for future research.

Exploring the effects of omalizumab in allergic asthma: an analysis of biomarkers in the EXTRA study

RATIONALE

For many patients with asthma, allergic airway inflammation is primarily a Th2-weighted process; however, heterogeneity in patterns of inflammation suggests phenotypic distinctions exist that influence disease presentation and treatment effects.

OBJECTIVES

To assess the potential of fractional exhaled nitric oxide (FE(NO)), peripheral blood eosinophil count, and serum periostin as biomarkers of Th2 inflammation and predictors of treatment effects of omalizumab.

METHODS

The EXTRA omalizumab study enrolled patients (aged 12-75 yr) with uncontrolled severe persistent allergic asthma. Analyses were performed evaluating treatment effects in relation to FE(NO), blood eosinophils, and serum periostin at baseline. Patients were divided into low- and high-biomarker subgroups. Treatment effects were evaluated as number of protocol-defined asthma exacerbations during the 48-week treatment period (primary endpoint).

MEASUREMENTS AND MAIN RESULTS

A total of 850 patients were enrolled. Data were available from 394 (46.4%), 797 (93.8%), and 534 (62.8%) patients for FE(NO), blood eosinophils, and serum periostin, respectively. After 48 weeks of omalizumab, reductions in protocol-defined exacerbations were greater in high versus low subgroups for all three biomarkers: FE(NO), 53% (95% confidence interval [CI], 37-70; P = 0.001) versus 16% (95% CI, -32 to 46; P = 0.45); eosinophils, 32% (95% CI, 11-48; P = 0.005) versus 9% (95% CI, -24 to 34; P = 0.54); and periostin, 30% (95% CI, -2 to 51; P = 0.07) versus 3% (95% CI, -43 to 32; P = 0.94).

CONCLUSIONS

The difference in exacerbation frequency between omalizumab and placebo was greatest in the three high-biomarker subgroups, probably associated with the greater risk for exacerbations in high subgroups. Additional studies are required to explore the value of these biomarkers in clinical practice. Clinical trial registered with www.clinicaltrials.gov (NCT00314574).

[Targeted therapies in severe asthma: the discovery of new molecules]

The pathophysiological mechanisms involved in the chronicity and phenotypic heterogeneity of asthma offer the prospect of new therapeutic opportunities. A better clinical and biological characterisation of selected patients has led to the development of targeted therapies. Studies are under way to demonstrate their efficacy and tolerance and also their impact on the natural history of the disease. This revue aims to examine the therapies, developed during the last ten years, that are based on the immunological mechanisms involved in the pathophysiology of asthma, essentially in its severe form. The rapid expansion of human monoclonal antibodies has allowed testing of various immunological pathways. Anti-IgE, anti- IL-5, and anti-IL-13 strategies seem the most promising. Antagonists to TNF-alpha and I'IL-4 have not succeeded in reducing the events related to severe asthma in a convincing manner. Molecules targeted against thymic stromal lymphopoietin (TSLP) and I'IL-9 are under development. These approaches are involved in the development of therapeutic programmes adapted to the patient's phenotype, that is to say a personalised approach to care.

Effectiveness of omalizumab in a patient with severe asthma, low serum IgE level, and lack of sensitized allergens induced by oral steroid therapy: the usefulness of impulse oscillation for assessment of omalizumab therapy

BACKGROUND

Omalizumab is a humanized monoclonal anti-IgE antibody that was recently approved for the treatment of severe allergic asthma. However, omalizumab is not licensed for allergic asthma in patients with a low serum IgE level (<30 IU/mL) or negative results for specific allergen tests.

CASE HISTORY

We present a patient with severe asthma and low serum IgE levels who had negative results for specific allergens induced by oral steroid therapy. Omalizumab administration improved asthma exacerbated forced expiratory volume in 1 s (FEV(1)) and respiratory resistance measurements based on the impulse oscillation technique (Mostgraph-01). The response to omalizumab therapy was evidenced by a decrease in airway resistance at 1 month.

CONCLUSIONS

The findings of this case report indicate that omalizumab treatment had beneficial effects in a patient with severe asthma and low total serum IgE levels with negative results for specific IgE, which may have been induced by long-term corticosteroid administration.

Immunologic therapeutic interventions in asthma: impact on natural history

The discovery of new pathobiological pathways involved in asthma chronicity and reliefs offers novel therapeutic avenues. Enhanced phenotyping criteria associated with simple biologic characterization allowed to test targeted interventions in selected patients. Long-term studies are de facto lacking but required to address their impact on the natural history of the disease. Here, the authors review all potential available therapeutics based on immunologic pathways involved in asthma pathophysiology during the last decade.

Omalizumab: clinical use for the management of asthma

Omalizumab, a humanized monoclonal antibody that binds circulating IgE antibody, is a treatment option for patients with moderate to severe allergic asthma whose asthma is poorly controlled with inhaled corticosteroids and inhaled long-acting β₂ agonist bronchodilators. This review considers the mechanism of action, pharmacokinetics, efficacy, safety and place in management of omalizumab in asthma and focuses particularly on key articles published over the last three years. Omalizumab reduces IgE mediated airway inflammation and its effect on airway remodeling is under investigation. Recent long-term clinical trials confirm the benefits of omalizumab in reducing exacerbations and symptoms in adults and in children with moderate to severe allergic asthma. No clinical or immunological factor consistently predicts a good therapeutic response to omalizumab in allergic asthma. In responders, the duration of treatment is unclear. The main adverse effect of omalizumab is anaphylaxis, although this occurs infrequently. Preliminary data from a five-year safety study has raised concerns about increased cardiovascular events and a final report is awaited. Clinical trials are in progress to determine whether omalizumab has efficacy in the treatment of non-allergic asthma.

Omalizumab in patients with severe asthma: the XCLUSIVE study

BACKGROUND AND AIMS

Although the efficacy and safety of omalizumab (OMA) in uncontrolled severe allergic asthma has been demonstrated in several randomised controlled trials (RCTs), information on the treatment in a practice-related setting is limited. Thus, the purpose of this prospective multi-centre study (XCLUSIVE) was to investigate the efficacy, compliance and utilisation of OMA therapy in real-life clinical practice in Germany.

METHODS

One hundred ninety-five asthmatic patients initiated on anti-Immunoglobulin E (IgE) IgE treatment were followed-up for 6 months. Forced expiratory volume in 1 s (FEV(1) ), exacerbation rate, days of absence, asthma symptoms [Asthma Control Questionnaire (ACQ)], a Global Evaluation of Treatment Effectiveness (GETE) and medication use were assessed.

RESULTS

Measured outcome variables improved after a 16-week treatment period with OMA (FEV(1) +13.7% predicted P < 0.05, exacerbation rate -74.9% P < 0.0001, days of absence -92.1% P < 0.001, ACQ -43.7% P < 0.0001). Investigators evaluated the effectiveness of OMA by GETE in 78.8% as excellent or good (responder), and in 12.6%/8.6% as moderate/poor or worse (non-responder). Responders demonstrated better improvement of FEV(1), exacerbation rate, days of absence, ACQ and reduction of oral corticosteroids compared with non-responders.

CONCLUSION

Results of effectiveness strongly suggest that the efficacy demonstrated in RCTs can be transposed to a clinical practice-related setting.

The History of IgE: From discovery to 2010

The discovery of IgE and the role of IgE-mediated inflammation gave clinical allergy a scientific backbone, and as a result, the reputation of the specialty allergy has increased considerably over the years. Allergy diagnosis was improved by assays for in vitro determination of the presence and concentration of IgE antibodies, and clinical knowledge also broadened, allowing better service for the increasing number of allergic individuals. Access to immune assays for allergens finally allowed characterization and standardization of allergen preparations used for diagnosis and allergen-specific immunotherapy. Improved basic molecular technologies have further increased our knowledge about the complex component composition of an allergen extract, introduced IgE-specific immunotherapy, and allowed the allergist to better handle even severe allergic reactions such as anaphylaxis.

Persistency of response to omalizumab therapy in severe allergic (IgE-mediated) asthma

BACKGROUND

The physician's global evaluation of treatment effectiveness (GETE) at 16 weeks has been shown to be the most effective assessment of response to omalizumab (XOLAIR®). This randomized, open-label, parallel-group study evaluated the persistency of treatment responder classification in patients receiving omalizumab added to optimized asthma therapy (OAT).

METHODS

Patients (12-75 years, n = 400) with severe allergic asthma, uncontrolled despite Global Initiative for Asthma 2004 Step 4 therapy, received OAT and omalizumab (n = 272) or OAT (n = 128) for 32 weeks. Response or nonresponse was evaluated at Weeks 16 and 32. Response was defined as an investigator's (physician's) GETE rating of excellent or good; nonresponse was defined as a rating of moderate, poor or worsening.

RESULTS

Three hundred and forty-nine patients had GETE ratings available at Weeks 16 and 32 (omalizumab n = 258, OAT n = 91). Omalizumab responders of about 171/187 (91.4%)and 44/71 (62.0%) omalizumab nonresponders at Week 16 persisted as responders or nonresponders at Week 32. The investigator's GETE at Week 16 predicted persistency of response or nonresponse to omalizumab at Week 32 for 83.3% (215/258) of patients. OAT patients showed a lower persistency of response (18/28 [64.3%]) and a higher persistency of nonresponse (57/63 [90.5%]) than omalizumab patients. Excellent and good GETE ratings in omalizumab-treated patients were reflected by improvements in exacerbation rates (P < 0.001), severe exacerbation rates (P = 0.023), hospitalizations (P = 0.003), total emergency visits (P = 0.026) and Asthma Control Questionnaire overall score (P < 0.001).

CONCLUSION

Response to omalizumab, as assessed by a physician's GETE at 16 weeks, is an effective predictor of continuing persistent response to omalizumab for the majority of patients.

Randomized trial of omalizumab (anti-IgE) for asthma in inner-city children

BACKGROUND

Research has underscored the effects of exposure and sensitization to allergens on the severity of asthma in inner-city children. It has also revealed the limitations of environmental remediation and guidelines-based therapy in achieving greater disease control.

METHODS

We enrolled inner-city children, adolescents, and young adults with persistent asthma in a randomized, double-blind, placebo-controlled, parallel-group trial at multiple centers to assess the effectiveness of omalizumab, as compared with placebo, when added to guidelines-based therapy. The trial was conducted for 60 weeks, and the primary outcome was symptoms of asthma.

RESULTS

Among 419 participants who underwent randomization (at which point 73% had moderate or severe disease), omalizumab as compared with placebo significantly reduced the number of days with asthma symptoms, from 1.96 to 1.48 days per 2-week interval, a 24.5% decrease (P<0.001). Similarly, omalizumab significantly reduced the proportion of participants who had one or more exacerbations from 48.8 to 30.3% (P<0.001). Improvements occurred with omalizumab despite reductions in the use of inhaled glucocorticoids and long-acting beta-agonists.

CONCLUSIONS

When added to a regimen of guidelines-based therapy for inner-city children, adolescents, and young adults, omalizumab further improved asthma control, nearly eliminated seasonal peaks in exacerbations, and reduced the need for other medications to control asthma. (Funded by the National Institute of Allergy and Infectious Diseases and Novartis; ClinicalTrials.gov number, NCT00377572.).

Quantitation of serum IgE by using chimeras of human IgE receptor and avian immunoglobulin domains

Anti-IgE therapeutics represent an efficient approach in the management of IgE-mediated allergic asthma. However, monitoring the reduction of IgE levels into a therapeutically efficient range requires the determination of residual serum IgE. We established an analytical approach to distinguish free and anti-IgE complexed serum IgE based on soluble derivatives of the human high-affinity IgE receptor. Soluble receptor derivatives represent an ideal means to analyze receptor antagonism by any ligand or blocking antibody. Therefore, the FcεRI ectodomain was fused with avian IgY constant domains that circumvent susceptibility to interference phenomena and improve assay performance. After production in HEK293 cells, subsequent characterization by enzyme-linked immunosorbent assay and immunoblotting confirmed the suitability of avian IgY constant domains for immobilization and detection purposes. To provide further insights into the different IgE reactivities, free allergen-specific IgE was also determined. Monitoring of sera from omalizumab-treated patients during the course of therapy revealed the applicability for assessment of omalizumab-complexed versus noncomplexed serum IgE. These parameters may allow correlation to clinical responses during anti-IgE therapy with the perspective of biomonitoring.