The anti-IgE antibody omalizumab reduces exacerbations and steroid requirement in allergic asthmatics

Omalizumab for the treatment of inadequately controlled allergic rhinitis: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Patients with moderate-to-severe allergic rhinitis who are inadequately controlled despite treatment according to current rhinitis management guidelines have a significant unmet medical need. Such patients have a negative impact on daily functioning and are at risk of developing serious comorbidities, such as asthma and chronic rhinosinusitis.

OBJECTIVE

To assess the efficacy and safety of omalizumab in poorly controlled allergic rhinitis under a meta-analysis framework.

METHODS

MEDLINE and the Cochrane Central Register of Controlled Trials were searched through September 2013. Studies on the efficacy of omalizumab in allergic rhinitis that assessed clinical outcomes were selected. Descriptive and quantitative information was extracted; mean differences and relative risk estimates were synthesized under a fixed or random effects model. Heterogeneity was assessed by using the Q statistic and the I(2) metric. Subgroup analyses were performed for the presence of specific immunotherapy treatment.

RESULTS

Of the 352 citations retrieved, 11 studies of 2870 patients were finally included. A statistically significant reduction in the daily nasal symptom severity score (standardized mean difference -0.67 [95% CI, -1.3 to -0.31]; P < .0001; I(2), 92%) and a statistically significant reduction in daily nasal rescue medication score (-0.22 [95% CI, -0.39 to -0.05; P = .01; I(2), 58%) were observed. There was not a statistically significant difference in the occurrence of any adverse event (relative risk 1.06 [95% CI, 0.94-1.19; I(2), 55%).

CONCLUSIONS

Omalizumab is statistically significantly associated with symptom relief, decreased rescue medication use, and improvement of quality of life in patients with inadequately controlled allergic rhinosinusitis.

Virus-induced modulation of lower airway diseases: pathogenesis and pharmacologic approaches to treatment

Uncomplicated upper respiratory viral infections are the most common cause of days lost from work and school and exert a major economic burden. In susceptible individuals, however, common respiratory viruses, particularly human rhinoviruses, also can have a major impact on diseases that involve the lower airways, including asthma, chronic obstructive pulmonary diseases (COPD) and cystic fibrosis (CF). Respiratory virus-induced wheezing illnesses in early life are a significant risk factor for the subsequent development of asthma, and virus infections may also play a role in the development and progression of airway remodeling in asthma. It is clear that upper respiratory tract virus infections can spread to the lower airway and trigger acute attacks of asthma, COPD or CF. These exacerbations can be life-threatening, and exert an enormous burden on health care systems. In recent years we have gained new insights into the mechanisms by which respiratory viruses may induce acute exacerbations of lower airway diseases, as well as into host defense pathways that may regulate the outcomes to viral infections. In the current article we review the role of viruses in lower airway diseases, including our current understanding on pathways by which they may cause remodeling and trigger acute exacerbations. We also review the efficacy of current and emerging therapies used to treat these lower airway diseases on the outcomes due to viral infection, and discuss alternative therapeutic approaches for the management of virus-induced airway inflammation.

Revision of omalizumab dosing table for dosing every 4 instead of 2 weeks for specific ranges of bodyweight and baseline IgE

The dosing level and frequency of omalizumab are guided by a dosing table based on total serum immunoglobulin E (IgE) and bodyweight. Using a validated, mathematical simulation model (based on concentration data from 8 studies), we evaluated the impact of a revised omalizumab dosing table (every 4 weeks dosing regimen) on the pharmacokinetic and pharmacodynamic profiles of free and total IgE. Safety analysis, in patients with high levels of exposure to omalizumab, was done using data from the clinical and post-marketing databases. The model accurately predicted observed omalizumab, free and total IgE concentrations. After reaching steady-state, the average increase in exposure was 10%, even for patients with the highest concentrations at the upper 97.5th percentile. Free IgE suppression slightly increased in the initial phase, and slightly reduced at the trough of the dosing cycle, but average suppression remained similar for both regimens. The safety profile of omalizumab was similar for patients receiving higher or lower doses. Thus, doubling the dose of omalizumab, in a subset of patients receiving 225-300 mg of omalizumab (every 2 weeks dosing regimen) can efficiently suppress free IgE without compromising safety or efficacy.

Novel treatments of asthma and allergic diseases

The prevalence of allergic diseases has considerably increased, mostly in industrialized countries (> 20%), and asthma affects approximately 300 million individuals worldwide. Current therapies are able to control symptoms although they do not modulate immunological dysregulation that characterizes allergic diseases. Over the last 30 years, only a few new drugs have been introduced on the market and they all act on Th2-type response which has a critical role in the pathogenesis of allergic diseases. Recently, a new scenario has been opened on Th17-cells, Th1-type cytokines and innate immune system components involved in the inflammatory pathogenesis of asthma and other allergic diseases. These findings suggest a promising therapeutic role of new agents that block the action of specific cytokines. Furthermore, the concept of an intrinsic structural defect in the bronchial epithelium paves the way to innovative therapeutic strategies. In this review we present an update on therapies for allergic diseases with special focus on 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.

Healthcare Resource Utilization in Patients Receiving Omalizumab for Allergic Asthma in a Real-World Setting

Introduction

Inadequately controlled asthma is associated with increased healthcare resource utilization. The eXpeRience registry was initiated to evaluate real-world outcomes in patients receiving omalizumab for uncontrolled persistent allergic asthma. The current analysis of data from the eXpeRience registry focuses on healthcare resource utilization and on absences from work or school.

Methods

The eXpeRience was a 2-year, multinational, non-interventional, observational registry conducted to investigate real-world outcomes among patients receiving omalizumab in accordance with country-specific prescribing criteria for the treatment of uncontrolled persistent allergic asthma. Asthma-related healthcare resource utilization (hospitalizations, emergency room visits or unscheduled-asthma-related doctor visits or interventions) and absences from work or school were assessed pre-treatment (12-month data were collected retrospectively at baseline) and at months 12 and 24 after the initiation of omalizumab treatment. Serious adverse event (SAE) data were also assessed.

Results

A total of 943 patients (mean age 45 years; female 65%) were enrolled in the registry. Overall, the mean (standard deviation [SD]) number of asthma-related medical healthcare uses per patient decreased from 6.2 (6.97) during the pre-treatment period to 1.0 (1.96) and 0.5 (1.28) at months 12 and 24, respectively. The mean (SD) number of work or school days missed due to asthma was also lower at months 12 (3.5 [17.28] and 1.6 [4.28], respectively) and 24 (1.0 [4.66] and 1.9 [5.46], respectively) compared with the pre-treatment period (26.4 [49.61] and 20.7 [27.49], respectively). The nature and frequency of SAEs in the eXpeRience registry were comparable to that seen in interventional clinical trials with omalizumab.

Conclusion

The results of the eXpeRience registry indicate that omalizumab is associated with reductions in healthcare utilization, and in the number of days of absence from work or school, in patients with uncontrolled persistent allergic asthma in the real-world setting.

Funding

Novartis Pharma AG, Basel, Switzerland.

Electronic supplementary material

The online version of this article (doi:10.1007/s13554-014-0019-z) contains supplementary material, which is available to authorized users.

Changes in blood eosinophilia during omalizumab therapy as a predictor of asthma exacerbation

INTRODUCTION

Omalizumab is a monoclonal anti-immunoglobulin E antibody developed for the treatment of severe allergic asthma. The number of exacerbations used as a parameter of omalizumab therapy efficacy may be insufficient in many cases due to a relatively short time to first evaluation (16 weeks). Therefore, it is advisable to look for parameters of more prognostic value while continuing omalizumab therapy.

AIM

To evaluate usefulness of analysis of changes of blood eosinophilia after 16 weeks of omalizumab therapy as a predictor of asthma exacerbations.

MATERIAL AND METHODS

The study was conducted on a group of 13 patients with severe persistent allergic asthma treated with omalizumab. Blood eosinophil counts were measured before and after 16 weeks of anti-IgE therapy. On the basis of percentage of eosinophilia decrease (> 50% or < 50% of the initial value), patients were divided into two groups. Analysis of the asthma exacerbation rate during 12 months and time to first exacerbation was performed.

RESULTS

In the group with a high decrease in blood eosinophil counts (group 1) we showed a statistically significantly lower asthma exacerbation rate in 12 months compared with the group with a low decrease in blood eosinophil counts (group 2) (p = 0.02). We also observed the tendency to longer time to first asthma exacerbation in group 1 compared to group 2 (p = 0.06).

CONCLUSIONS

Our results showed that a decrease in blood eosinophilia during omalizumab therapy can be a predictor of asthma exacerbation. Evaluation of changes in blood eosinophil count should be taken into the consideration while estimating response to anti-IgE therapy in patients with severe allergic asthma.

Mast cells, their subtypes, and relation to asthma phenotypes

Mast cells (MCs) are among the first cell types associated with allergies and asthma. Studies in human asthma have identified their presence in the lung submucosa and smooth muscle and also in the airway epithelium. As our understanding of the distribution and location of these MCs in the human airway has increased, it is clear that much remains to be understood regarding the presence and subtype of these MCs in relationship to asthma phenotypes, defined both clinically and on the basis of immunologic pathways. Human MCs have traditionally been divided into two major subtypes based on the protease granule content, with tryptase representing total MCs. There is emerging evidence that in the epithelium, MCs of an altered subtype (with tryptase, chymase, and/or carboxypeptidase A3) may play a role in the pathophysiology of poorly controlled, severe, Th2-associated asthma.

Monoclonal antibodies for the treatment of refractory asthma

PURPOSE OF REVIEW

A small proportion of patients with asthma have severe disease characterized by persistent airflow obstruction, airway hyperresponsiveness and eosinophilic airway inflammation. This review focuses on the clinical efficacy of inhibiting T helper 2-cytokine-mediated inflammatory responses using monoclonal antibodies directed against immunoglobulin E (IgE), interleukin (IL)-5, and IL-4/IL-13 in patients with severe refractory asthma.

RECENT FINDINGS

The heterogeneity of airway inflammation in severe asthma has led to the recognition of multiple pathophysiologically distinct severe asthma endotypes. Biomarkers are being developed and evaluated to identify these endotypes and to guide the use of specific biologics in the appropriate patients who remain uncontrolled on high doses of inhaled corticosteroids and long-acting bronchodilators or oral corticosteroids. Examples include the efficacy of omalizumab in patients with severe refractory atopic asthma characterized by raised serum total IgE, mepolizumab, reslizumab, and benralizumab in patients with recurrent eosinophilic exacerbations characterized by blood and sputum eosinophilia despite high doses of corticosteroids, and lebrikizumab, pitrakinra, dupilumab, and tralokinumab that target the IL-4/IL-13 signalling pathways in patients with eosinophilic asthma or raised serum periostin.

SUMMARY

In severe refractory asthma, both an understanding of the underlying pathophysiologic mechanisms driving airway inflammation and the identification of appropriate biomarkers in individual patients are critical in guiding the use of biologics and monoclonal antibodies that target the specific pathological processes.

Omalizumab in asthma: an update on recent developments

IgE is central to the pathophysiology of allergic asthma. Omalizumab, a humanized anti-IgE mAb, specifically binds free IgE and interrupts the allergic cascade by preventing binding of IgE with its high-affinity FcεRI receptors on mast cells, antigen-presenting cells, and other inflammatory cells. The clinical efficacy of omalizumab has been well documented in a number of clinical trials that involve adults, adolescents, and children with moderate-to-severe and severe allergic asthma. In these studies, omalizumab reduced exacerbations, asthma symptoms, inhaled corticosteroid and rescue medication use, and improved quality of life relative to placebo or best standard of care. Similar benefits have been reported in observational studies in "real-world" populations of patients. Results from recent pooled data from randomized clinical trials and from a large prospective cohort study provide reassurance about the long-term safety of omalizumab. Omalizumab dosing is individualized according to body weight and serum-IgE level, and recent adjustments to the dosing algorithm in Europe have enabled more patients to be eligible for treatment. Ongoing and future research is investigating the optimal duration of therapy, accurate predictors of response to treatment, and efficacy in nonatopic asthma as well as other IgE-mediated conditions.

An update on biologic-based therapy in asthma

Although it is recognized that airway inflammation is key to asthma pathogenesis, the marked heterogeneity in its clinical course and variations in response to treatment make it a challenging condition for the development of novel and effective biologic-based therapies. Biopharmaceutical approaches have identified new therapies that target key cells and mediators that drive inflammatory responses in the asthmatic lung. Such an approach resulted in the development of biologics targeted at inhibiting IL-4, IL-5 and IL-13. With the notable exception of the anti-IgE monoclonal antibody omalizumab, early clinical trials with cytokine-targeted biologics in patients with asthma were, for the most part, disappointing, despite being highly effective in animal models of asthma. It is becoming apparent that significant clinical effects with anticytokine-based therapies are more likely in carefully selected patient populations that take asthma phenotypes into account. The development of discriminatory biomarkers and genetic profiling may aid identification of such patients with asthma. This review summarizes recent evidence demonstrating the effectiveness or otherwise of monoclonal antibody-based therapies in patients with asthma.

Biologic therapy in asthma: entering the new age of personalized medicine

OBJECTIVE

Asthma is a common chronic disease with various phenotypes and therapeutic responses. Unlike other diseases, current anti-inflammatory treatment with corticosteroids does not include any reference to biological measures which may vary among different asthma phenotypes. Morbidity from uncontrolled asthma suggests a need for specific targeted treatment approaches such as biologic medications. In half of asthmatics, chronic airway inflammation may be driven by T helper (Th)-2 cells, which release pro-inflammatory cytokines, such as interleukin (IL)-4, IL-5 and IL-13, contributing to eosinophil inflammation and IgE production. Earlier studies of cytokine-targeted biologic therapy on non-phenotyped asthma patients were generally not clinically effective.

METHODS

Literature published from 1958-2013 was identified through PubMed using the search terms which included asthma and therapy. A total of 32 studies were reviewed covering both pediatric and adult asthmatics and included double-blind randomized placebo-controlled trials testing efficacy of biologic agents to treat asthma.

RESULTS

More recent approaches to personalized medicine with expression profiling studies, genetic analysis and clinical biomarkers of Th2 inflammation have allowed identification of asthma phenotypes including a Th2 "high" phenotype. Studies targeting IgE, IL-5, IL-13 and the IL4 receptor alpha chain have shown some efficacy in phenotyped patients. For those without evidence of Th2 inflammation, no specific therapies have been identified.

CONCLUSIONS

In recent years, the identification of Type-2 cytokine "high" asthma in numerous studies has predicted the clinical response to the Th2 associated therapies. It is not yet clear whether all Type 2 high asthma will respond similarly to IL-4, 5 and 13 approaches.

Evaluation of two commercial omalizumab/free IgE immunoassays: implications of use during therapy

BACKGROUND

The anti-IgE monoclonal antibody, omalizumab, is approved in the US as add-on therapy for patients ≥12 years of age with moderate-to-severe persistent allergic asthma. Omalizumab is administered according to the US Food and Drug Administration approved dosing table included in the prescribing information. The dosing table was developed using Genentech's free IgE assay and is designed to achieve free serum IgE levels of <50 ng/mL, known to be associated with clinical benefit. Lack of clinical benefit in a subset of patients on omalizumab has prompted demand for commercial free IgE assays to guide omalizumab dosing. To date, two commercial free IgE assays marketed by ViraCor-IBT (no longer offered) and BioTeZ have been available to physicians.

OBJECTIVE

This study compares the results generated from the two commercial free IgE assays with the free IgE levels generated by the Genentech assay.

METHODS

Two serum sample sets were prepared using 20 samples from patients with a wide range of IgE and omalizumab from an omalizumab clinical trial and 36 samples from omalizumab-naïve patients. Different amounts of omalizumab were added to the 36 omalizumab naïve samples based on measured total IgE levels to ensure that a good range of IgE and omalizumab was represented in the study samples. Samples were randomized for blinded analysis of free IgE levels using the Genentech, ViraCor-IBT and BioTeZ free serum IgE assays. Analysis of samples in the ViraCor-IBT assay were conducted by ViraCor-IBT and the analysis of samples using the Genentech and BioTeZ assay methods were conducted by a third party contract research organization.

RESULTS

The ViraCor-IBT and BioTeZ free IgE assays demonstrated significantly higher free IgE levels than the Genentech free IgE assay. Twenty-nine of 56 samples tested <50 ng/mL in the Genentech assay; of these, 12/29 (41%) and 20/29 (69%) tested >50 ng/mL in the BioTeZ and ViraCor-IBT assays, respectively. In the BioTeZ free IgE evaluations, 11/20 samples that were re-tested had inter-assay differences ranging from 40-190%.

CONCLUSIONS

Free ligand (such as IgE) measurements are challenging and dependent on the method and reagents used. The Viracor-IBT and BioTeZ methods tend to over-estimate free serum IgE levels compared with the Genentech free IgE assay. Using these assays to monitor therapy and adjust omalizumab doses post treatment is considered off-label use and could lead to a potential risk for unnecessary treatment and/or risk to patient safety.

Treating severe allergic asthma with anti-IgE monoclonal antibody (omalizumab): a review

Increased asthma severity is not only associated with enhanced recurrent hospitalization and mortality but also with higher social costs. Several cases of asthma are atopic in nature, with the trigger for acute asthma attacks and chronic worsening of inflammation being allergens inducing an immune, IgE mediated response. Anti-inflammatory treatments are effective for most of asthma patients, but there are subjects whose disease is incompletely controlled by inhaled or systemic corticosteroids and these patients account for about 50% of the healthcare costs of asthma. Omalizumab is a biological engineered, humanized recombinant monoclonal anti-IgE antibody developed for the treatment of allergic diseases and with clear efficacy in adolescent and adult patients with severe allergic asthma. The anti-IgE antibody inhibits IgE functions blocking free serum IgE and inhibiting their binding to cellular receptors. By reducing serum IgE levels and IgE receptor expression on inflammatory cells in the context of allergic cascade, omalizumab has demonstrated to be a very useful treatment of atopic asthma, improving quality of life of patients with severe persistent allergic asthma that is inadequately controlled by currently available asthma medications. Several trials have demonstrated that this therapy is well tolerated and significantly improves symptoms and disease control, reducing asthma exacerbations and the need to use high dosage of inhaled corticosteroids.

Diagnosis and management of eosinophilic asthma: a US perspective

Eosinophilic asthma is now recognized as an important subphenotype of asthma based on the pattern of inflammatory cellular infiltrate in the airway. Eosinophilic asthma can be associated with increased asthma severity, atopy, late-onset disease, and steroid refractoriness. Induced sputum cell count is the gold standard for identifying eosinophilic inflammation in asthma although several noninvasive biomarkers, including fractional exhaled nitric oxide and periostin, are emerging as potential surrogates. As novel therapies and biologic agents become increasingly available, there is an increased need for specific phenotype-directed treatment strategies. Greater recognition and understanding of the unique immunopathology of this asthma phenotype has important implications for management of the disease and the potential to improve patient outcomes. The present review provides a summary of the clinical features, pathogenesis, diagnosis, and management of eosinophilic asthma.

Profile of patients treated with omalizumab in routine clinical practice in Spain

BACKGROUND

Omalizumab is indicated in patients with severe allergic asthma not controlled by high-dose inhaled glucocorticoids and long-acting beta-agonists. Few data are available on the profile of patients treated with this drug in routine clinical practice in Spain.

OBJECTIVE

To describe the profile of patients with severe allergic asthma treated with omalizumab and the course of the disease after a period of treatment.

METHODS

Retrospective, multicentre study, recording the data on patients of either sex and ≥12 years with uncontrolled severe allergic asthma, previously treated with omalizumab. Data were evaluated in relation to pulmonary function, symptoms, quality of life, and concomitant anti-asthma treatment before the prescription of omalizumab and at the time of the study visit.

RESULTS

214 patients were evaluable (mean age=48.2±17.7 years; mean age at the time of diagnosis=26.6±16.5 years). 90.7% had experienced exacerbations the year before receiving omalizumab, and the mean total IgE level was 273±205.4IU/ml. The mean monthly dose was 380.5±185.4mg. Compared with the baseline situation, differences were observed after treatment with omalizumab in mean FEV1 (62.7±15.9% vs. 70.8±18.7%), in the proportion of patients requiring oral corticosteroids (47.7% vs. 14.0%), and in the ACQ and AQLQ scores. 32.7% of the patients received doses not recommended by the Summary of Product Characteristics (SPC).

CONCLUSIONS

Profile of asthmatic patients treated with omalizumab predominantly corresponds to uncontrolled severe asthma cases, in accordance with SPC's indications. The results of the study suggest a favourable clinical course similar to that observed in other studies.

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.

Observational study in severe asthmatic patients after discontinuation of omalizumab for good asthma control

INTRODUCTION

Severe persistent asthma represents a major and costly public health issue. There is evidence that long-term treatment with omalizumab might have disease-modifying activity but data on the consequences of discontinuing treatment after a positive response are limited. The purpose of this study was to investigate-in real-life prescribing conditions-what happens when omalizumab is discontinued in patients with severe, persistent allergic asthma who have responded well to omalizumab treatment.

METHODS

An observational, descriptive, cross-sectional, retrospective study to establish the time to loss of asthma control after the discontinuation of courses of omalizumab treatment of varying duration.

RESULTS

24 lung specialists reviewed data from 61 responder patients who had discontinued omalizumab after a mean duration of 22.7 ± 13.1 [range: 2.5; 59.5] months of treatment. Loss of asthma control was documented in 34 patients (55.7%) with a median interval between discontinuation and loss of control of 13.0 months (mean 20.4 ± 2.6 [95% CI: 8.3-28.1]). No correlation was detected between time to loss of control and duration of treatment, although control tended to be sustained for longer in patients whose response had been classified as "excellent" as opposed to "good" (median: 17.0 vs. 12.8 months; NS).

DISCUSSION

The discontinuation of omalizumab was not associated with any rebound effect or exacerbation of the disease, and control was sustained throughout the follow-up period of at least 6 months in nearly half of all patients, including all of those who had been treated for 3.5 years or more. After the reintroduction of omalizumab, 4 out of 20 patients did not respond again.

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.

Anti-IgE therapy to Kimura's disease: a pilot study

Kimura's disease is a chronic disease that is characterized by subcutaneous granuloma of soft tissues in the head and neck region, increased eosinophil counts and high serum IgE levels. It is thought to be an IgE-mediated disease. Omalizumab, a monoclonal antibody, has recently been suggested as a potential new systemic treatment for IgE-mediated diseases, based on its efficacy in treating asthma and allergic rhinitis. We report a study of three patients with Kimura's disease who received anti-IgE (omalizumab) treatment. All patients were treated with a fixed schedule of eight cycles of omalizumab 300mg, administered subcutaneously at intervals of 2 weeks. The size of tumorous regions was evaluated by MRI at base line and after 4 months of treatment. Blood samples were taken every month. In each of the patients, the size of tumorous regions and the peripheral blood eosinophil and basophil counts were all decreased after the treatment. These results suggest that omalizumab may be valuable for treatment of Kimura's disease.

Severe asthma and its phenotype

The phenotype of severe, or difficult, asthma is poorly understood, but recent studies have been informative. Factors associated with severe asthma include the presence of co-morbidities such as sinusitis, obesity and gastroesophageal reflux, poor adherence with prescribed medical regimens, and a severe underlying disease process. The worst long-term prognosis in severe asthma is associated with the presence of persistent airflow limitation and exacerbations. Individualization of therapy based on phenotype is highly recommended.

Reduction in oral corticosteroid use in patients receiving omalizumab for allergic asthma in the real-world setting

Background

Oral corticosteroids (OCS) are commonly administered in patients with severe persistent allergic asthma. Despite their efficacy, they are associated with a wide variety of adverse events. The eXpeRience registry was set up to investigate real-world outcomes among patients receiving omalizumab for the treatment of uncontrolled allergic asthma. Here, we present the effect of omalizumab treatment on OCS use.

Methods

eXpeRience was a 2-year, multinational, non-interventional, observational registry of patients receiving omalizumab for uncontrolled allergic asthma. OCS use (proportion of patients on maintenance OCS, mean total daily OCS dose and change in status of OCS therapy) was assessed at baseline, 16 weeks, and 8, 12, 18, and 24 months after the initiation of omalizumab. Response to omalizumab was assessed using the physician’s Global Evaluation of Treatment Effectiveness (GETE) at approximately Week 16. Safety data were also recorded.

Results

A total of 943 patients (mean age, 45 years; female, 64.9%) were enrolled in the registry, 263 of whom were receiving maintenance OCS at baseline. The proportion of patients taking maintenance OCS was markedly lower at Months 12 (16.1%) and 24 (14.2%) than at baseline (28.6%; intent-to-treat population). GETE status was determined in 915 patients receiving omalizumab: 64.2% were responders (excellent or good response), 30.7% were non-responders (moderate, poor or worsening response); 5.1% had no assessment. The frequency of serious adverse events was comparable to that seen in controlled trials of omalizumab.

Conclusions

Omalizumab use is associated with an OCS-sparing effect in patients with uncontrolled persistent allergic asthma in the real-world setting.

Role of periostin, FENO, IL-13, lebrikzumab, other IL-13 antagonist and dual IL-4/IL-13 antagonist in asthma

INTRODUCTION

Asthma markedly diminishes quality of life due to limited activity, absences from work or school and hospitalizations. Patients with severe asthma which are not controlled despite taking effective therapy are most in need of new treatment approaches. IL-13 was demonstrated as 'central mediator of allergic asthma'.

AREAS COVERED

IL-13 has been implicated in the pathogenesis of asthma, idiopathic pulmonary fibrosis and COPD. IL-13 levels in the sputum and bronchial biopsy samples remain elevated in severe asthma despite the use of inhaled and systemic corticosteroids. Thus, IL-13 is a mediator involved in corticosteroid resistance. Periostin enhances profibrotic TGF-β signaling in subepithelial fibrosis associated with asthma. IL-13 induces bronchial epithelial cells to secrete periostin. Periostin may be a biomarker for Th2 induced airway inflammation. Lebrikizumab is a monoclonal antibody against IL-13. Lebrikizumab improved lung function in asthmatics who were symptomatic despite treatment with long acting beta agonist and inhaled corticosteroids and provided benefit in the treatment of severe uncontrolled asthma.

EXPERT OPINION

Lebrikizumab block IL-13 signaling through the IL-13Rα1/IL-4Rα receptor. There was a larger reduction in FENO in the high periostin subgroup than in the low periostin subgroup (34.4 vs 4.3%). Serum CCL17, CCL13 and total IgE levels decreased in the lebrikizumab group.

Omalizumab in the treatment of chronic urticaria

Omalizumab is a monoclonal anti-immunoglobulin E antibody currently only approved for use in severe, refractory asthma. In recent years, many authors have reported satisfactory results with omalizumab in patients with difficult-to-treat chronic urticaria. As a result, clinical trials were undertaken to broaden the indication of omalizumab to include chronic urticaria, and the drug was recently cited as a third-line treatment after selective antihistamines at high doses in a consensus document on the treatment of chronic urticaria. In this article our aim is to provide a comprehensive update on the use of omalizumab in the treatment of chronic urticaria. The structure of this biologic agent and its possible mechanisms of actions in this setting will be presented. Treatment strategies and the different dosage regimens used in the series of cases published to date will also be reviewed. Finally, we will discuss the adverse effects that may arise with treatment and the recommended strategies for minimizing the most feared effect, anaphylaxis. Based on the experience of many researchers, omalizumab is emerging as a novel treatment for certain types of spontaneous refractory chronic urticaria and has shown promising results in this setting. The drug has a good safety profile and the main limitation is its high cost.

Efficacy of omalizumab in asthmatic patients with IgE levels above 700 IU/mL: a retrospective study

BACKGROUND

Omalizumab is approved for patients with poorly controlled asthma with serum IgE levels between 30 and 700 IU/mL and positive test results for perennial allergens. Its efficacy in patients with IgE levels greater than 700 IU/mL is unclear.

OBJECTIVE

To evaluate the response of asthmatic patients treated with omalizumab with IgE levels greater than 700 IU/mL.

METHODS

Asthmatic patients treated with omalizumab for 6 months or longer with elevated IgE levels were evaluated retrospectively. Emergency department (ED) visits, hospitalizations, change in forced expiratory volume in 1 second, corticosteroid bursts, and Asthma Control Test (ACT) scores were recorded for a period of 6 months before and after treatment.

RESULTS

Twenty-six patients with an IgE level greater than 700 IU/mL (group 1) were matched by age, sex, and severity of asthma to patients with an IgE of 30 to 700 IU/mL (group 2). The mean numbers of ED visits before and after treatment were 0.96 vs 0.23 (P = .008) in group 1 and 0.65 vs 015 (P = .02) in group 2. Both group 1 and group 2 had an improvement in asthma control based on the mean ACT score before and after treatment (15.6 vs 18.9 [P = .02] and 15.4 vs 19 [P = .006], respectively). There was also a significant reduction in the frequency of systemic corticosteroid use during the 6 months before and after treatment (2.58 vs 0.96 [P < .001] and 2.62 vs 1.23 [P < .001] systemic steroid treatments, respectively).

CONCLUSION

Omalizumab was as effective in reducing ED visits, controlling asthma symptoms, and reducing the need for systemic corticosteroids in patients with IgE levels greater than 700 IU/mL compared with patients with levels of 30 to 700 IU/mL.

Complex phenotypes in asthma: current definitions

Asthma is increasingly recognized as a heterogeneous disease. However, identification of different subgroups or phenotypes has been complex and controversial. The convergence of both clinical and statistical approaches to grouping patients and their characteristics, in association with increasing recognition of molecular patterns is now beginning to move the field forward. Integration of efficacy data with targeted molecular therapies will eventually lead to more complete understanding of these "molecular phenotypes" and eventually lead to the identification of fully defined endotypes. This process should improve our ability to treat more complex and severe forms of asthma.

A study into efficacy of omalizumab therapy in patients with severe persistent allergic asthma at a tertiary referral centre for asthma in Ireland

BACKGROUND

Asthma is a chronic airway disease characterized by airway inflammation, bronchial hyperresponsiveness and airflow obstruction. Patients with persistent symptoms despite maximum standard treatment as per Global Initiative of Asthma guidelines are considered to have severe persistent asthma. Omalizumab is a recombinant humanized monoclonal antibody licenced for use as an add-on therapy in these patients.

AIM

To assess the clinical benefit amongst responders to omalizumab therapy at a tertiary referral centre.

METHODS

This was a retrospective audit assessing the effect of omalizumab therapy on asthma control, frequency of exacerbation and hospitalization rates over 6 months before and after therapy.

RESULTS

The study included 30 responders (14 females). There was a reduction in exacerbation and hospitalization rates following initiation of omalizumab, 73 and 91%, respectively (P-value < 0.0001). The number of exacerbations decreased from 3.48 ± 2.20 to 0.93 ± 0.83 and the mean number of admissions decreased from 1.07 ± 1.1 to 0.1 ± 0.40 over the study duration (P < 0.001). There was 73% reduction in the weekly need for rescue salbutamol therapy with mean of 30.33 ± 6.49 puffs to 8.23 ± 1.51 puffs after omalizumab therapy (P < 0.0001). Seventy-nine per cent of patients were able to reduce their maintenance oral corticosteroid therapy.

CONCLUSION

Overall, responders to omalizumab therapy are less likely to experience an asthma exacerbation and hospitalization. They were also more likely to reduce maintenance corticosteroid therapy and the need for rescue reliever therapy. These data suggest that omalizumab has proven effective in improving health outcomes for a cohort of carefully selected patients with severe allergic asthma in Ireland.

Does omalizumab make a difference to the real-life treatment of asthma exacerbations?: Results from a large cohort of patients with severe uncontrolled asthma

BACKGROUND

Omalizumab has been shown to decrease the risk of hospitalization or ED visits in patients with uncontrolled severe allergic asthma compared with placebo. This longitudinal study observed the conditions under which omalizumab is prescribed in real-life settings and assessed whether its use as an add-on therapy alongside standard treatments decreases the risk of severe asthmatic exacerbations.

METHODS

A cohort of adult patients with uncontrolled severe asthma despite optimal treatment with inhaled and oral corticosteroids and a long-acting b 2 -agonist but no treatment with omalizumab upon entry was assembled. Risk of hospitalization or ED visits for asthma exacerbation was assessed using the Andersen-Gill extension of the Cox model for repeated events, controlling for age, sex, smoking history, BMI, gastroesophageal reflux, allergic status, allergic rhinitis, treatment, and hospitalization or ED visits for asthma in the 2 months prior to omalizumab treatment.

RESULTS

Overall, 163 physicians recruited 767 patients, of whom 374 took omalizumab at least once (mean observation period, 20.4 months). Omalizumab use was associated with an adjusted relative risk of 0.57 (95% CI, 0.43-0.78) for hospitalization or ED visits for asthma. In users of omalizumab, the adjusted relative risk of hospitalization or ED visits for asthma during omalizumab treatment vs nontreatment periods was 0.40 (95% CI, 0.28-0.58).

CONCLUSIONS

Add-on omalizumab is associated with a significantly decreased risk of hospitalization or ED visits in patients with uncontrolled severe asthma in real-life practice.

Novel therapies in asthma: leukotriene antagonists, biologic agents, and beyond

Asthma is one of the most common conditions seen in clinical practice and carries both a significant disease burden in terms of patient morbidity and a high economic burden in both direct and indirect costs. Despite this, it remains a comparatively poorly understood disease, with only modest advances in treatment over the past decade. Corticosteroids remain the cornerstone of therapy. Both patient compliance with medications and physician adherence to evidence-based guidelines are often poor, and a high percentage of patients continue to have inadequately controlled disease even with optimal therapy. Following a contextual overview of the current treatment guidelines, this review focuses on novel asthma therapies, beginning with the introduction of the leukotriene receptor antagonist zafirlukast in the 1990s, continuing through advanced endoscopic therapy and into cytokine-directed biologic agents currently in development. Along with clinically relevant biochemistry and pharmacology, the evidence supporting the place of these therapies in current guidelines will be highlighted along with data comparing these agents with more conventional treatment. A brief discussion of other drugs, such as those developed for unrelated conditions and subsequently examined as potential asthma therapies, is included.

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).

The eXpeRience registry: the 'real-world' effectiveness of omalizumab in allergic asthma

Omalizumab has demonstrated therapeutic benefits in controlled clinical trials. Evaluation of outcomes in real-world clinical practice is needed to provide a complete understanding of the benefits of omalizumab treatment. eXpeRience was a 2-year, international, single-arm, open-label, observational registry that evaluated real-world effectiveness, safety and use of omalizumab therapy in 943 patients with uncontrolled persistent allergic asthma. Effectiveness variables (physician's Global Evaluation of Treatment Effectiveness [GETE], and change from baseline in exacerbation rate, symptoms, rescue medication use, and oral corticosteroid [OCS] use) were evaluated at pre-specified time-points. Safety data were also recorded. By physician's GETE, 69.9% of patients were responders to omalizumab after 16 (±1) weeks. The proportion of patients with no clinically significant exacerbations increased from 6.8% during the 12-month pre-treatment period to 54.1% and 67.3% at Months 12 and 24, respectively. Symptoms and rescue medication use at Month 24 were reduced by >50% from baseline. Maintenance OCS use was lower at Month 24 (14.2%) compared with Month 12 (16.1%) and baseline (28.6%). Overall, omalizumab had an acceptable safety profile. The results from eXpeRience indicate that omalizumab was associated with improvements in outcomes in patients with uncontrolled persistent allergic asthma; these improvements were consistent with the results of clinical trials.

Anti-IgE--emerging opportunities for Omalizumab

INTRODUCTION

Omalizumab is a recombinant DNA-derived humanized IgG1 monoclonal antibody that selectively binds to free and membrane-bound immunoglobulin E (IgE) antibodies. Omalizumab has been licensed for use in severe allergic asthma. A search on the website clinicaltrials.gov reveals there are currently 109 clinical trials with Omalizumab of which 46 are for conditions other than asthma.

AREAS COVERED

In addition to asthma, Omalizumab has been investigated in various other conditions including perennial and seasonal allergic rhinitis (AR), peanut allergy, latex allergy, atopic dermatitis, chronic urticaria (CU), idiopathic anaphylaxis, mastocytosis, eosinophilic gastroenteritis and nasal polyposis. This review aims to look at the various randomised and non-randomised clinical trials, case series and case reports for the role of Omalizumab in conditions other than asthma. Numerous clinical trials have shown a positive light on the role of Omalizumab in conditions other than asthma.

EXPERT OPINION

We feel that the future of Omalizumab would include a more diverse range of clinical conditions, and future trials should not only look into the clinical usefulness but also the economic impact of using this interesting molecule.

The use of biological agents for the treatment of fungal asthma and allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is a virulent manifestation of the Th2 asthma endotype that includes asthma with fungal sensitization, raising the feasibility of biological therapies targeting Th2 pathway molecules or cells. The first molecule amenable to clinical intervention with a biological was IgE. Omalizumab, a humanized monoclonal antibody (Mab), targets the same epitope on the IgE CH3 region that binds to and crosslinks high-affinity receptors on mast cells and basophils, thereby initiating the allergic inflammatory cascade. Omalizumab is licensed for allergic asthma and has been beneficial in uncontrolled studies of ABPA, reducing exacerbations and steroid requirements. Trials of several Mabs directed against the Th2 cytokine IL-5 show clinical benefit in patients with a severe refractory eosinophilic asthma phenotype, while a Mab against IL-13 is effective in asthma patients with a Th2-high endotype. Immunodulation is also feasible with small molecule biologicals, such as antisense oligodeoxynucleotides and cholecalciferol. Controlled trials of Th2-inhibiting biologicals in patients with ABPA and severe asthma with fungal sensitization appear warranted.

Reassessment of omalizumab-dosing strategies and pharmacodynamics in inner-city children and adolescents

BACKGROUND

Treatment regimens for omalizumab are guided by a dosing table that is based on total serum IgE and body weight. Limited data exist about onset and offset of omalizumab efficacy in children and adolescents or subgroups that most benefit from treatment.

OBJECTIVES

Post hoc analyses were conducted to (1) examine patient characteristics of those eligible and ineligible for omalizumab, (2) describe onset of effect after initiation of omalizumab and offset of treatment effect after stopping therapy, and (3) determine whether the efficacy differs by age, asthma severity, dosing regimen, and prespecified biomarkers.

METHODS

Inner-city children and adolescents with persistent allergic asthma were enrolled in the Inner-City Anti-IgE Therapy for Asthma trial that compared omalizumab with placebo added to guidelines-based therapy for 60 weeks.

RESULTS

Two hundred ninety-three of 889 participants (33%) clinically suitable for omalizumab were ineligible for dosing according to a modified dosing table specifying IgE level and body weight criteria. Baseline symptoms were comparable among those eligible and ineligible to receive omalizumab, but other characteristics (rate of health care utilization and skin test results) differed. The time of onset of omalizumab effect was <30 days and time of offset was between 30 and 120 days. No difference in efficacy was noted by age or asthma severity, but high exhaled nitric oxide, blood eosinophils, and body mass index predicted efficacy.

CONCLUSIONS

A significant portion of children and adolescents particularly suited for omalizumab because of asthma severity status may be ineligible due to IgE >1300 IU/mL. Omalizumab reduced asthma symptoms and exacerbations rapidly; features associated with efficacy can be identified to guide patient selection.

Population-based efficacy modeling of omalizumab in patients with severe allergic asthma inadequately controlled with standard therapy

Omalizumab, a recombinant humanized monoclonal antibody, is the first approved anti-immunoglobulin E (IgE) agent for the treatment of subjects with moderate to severe persistent allergic asthma that are inadequately controlled by the standard of care. The objective of this study was to quantitatively characterize relationships between serum free IgE and pulmonary function (as measured by forced expiratory volume in 1 s [FEV1]) as well as serum free IgE and airway inflammation (as measured by fractional exhaled nitric oxide [FeNO]) using population-based efficacy models. Data were collected from patients in the EXTRA trial who received omalizumab or placebo 150 to 375 mg subcutaneously every 2 or 4 weeks from week 0 to 48 with constant standard of care as background therapy. None of the covariates evaluated, including demographics, disease status, and baseline pharmacodynamic biomarkers, were significant in explaining the variability in the FEV1 or FeNO response to omalizumab. Results from the efficacy models further confirmed the current omalizumab dosing rationale based on the mean target free IgE level of 25 ng/ml and quantified the variability for the target. In addition, the resulting population models could be used to predict population FEV1 or FeNO response for omalizumab and/or other anti-IgE therapeutics for which PK-IgE models are constructed.

Targeting eosinophils in allergy, inflammation and beyond

Eosinophils can regulate local immune and inflammatory responses, and their accumulation in the blood and tissue is associated with several inflammatory and infectious diseases. Thus, therapies that target eosinophils may help control diverse diseases, including atopic disorders such as asthma and allergy, as well as diseases that are not primarily associated with eosinophils, such as autoimmunity and malignancy. Eosinophil-targeted therapeutic agents that are aimed at blocking specific steps involved in eosinophil development, migration and activation have recently entered clinical testing and have produced encouraging results and insights into the role of eosinophils. In this Review, we describe recent advances in the development of first-generation eosinophil-targeted therapies and highlight strategies for using personalized medicine to treat eosinophilic disorders.

Anti-immunoglobulin e therapy

The importance of immunoglobulin E (IgE) in atopic disorders such as asthma, allergic rhinitis, food allergies, and atopic dermatitis is well established. Elevation of total serum IgE is typically found in many atopic patients, and in predisposed individuals, allergen-specific IgE is produced. The availability of humanized monoclonal antibodies against IgE has provided a new therapeutic option and tool to explore the role IgE in allergic diseases and the effects of inhibiting IgE itself. Omalizumab is a humanized, monoclonal antibody that recognizes and binds to the Fc portion of the IgE molecule. Administration of omalizumab results in a rapid and substantial decrease in free IgE in serum. Consequently, the activity of cell populations involved in allergic inflammation, including mast cells, eosinophils, basophils, and antigen-presenting cells, is affected as well. Clinically, anti-IgE therapy has already been proven to be useful in the treatment of asthma and allergic rhinitis. The aim of this review is to provide an overview of the mechanisms of action of anti-IgE therapy as well as its efficacy in the treatment of allergic diseases, especially asthma. Considerations regarding dosing and safety of omalizumab will be addressed as well.

Redefining approaches to asthma: developing targeted biologic therapies

Asthma is a chronic respiratory disorder canonically associated with type 2 airway inflammation as characterized by elevated levels of eosinophils, immunoglobulin E, and cytokines including interleukin (IL) 4, IL5, IL9, and IL13 and tumor necrosis factor (TNF) α. However, mounting evidence has shown that considerable heterogeneity exists in human asthma in terms of the nature and intensity of airway inflammation. While many asthma patients achieve acceptable control of symptoms with standard-of-care therapies such as β₂-adrenergic agonists and inhaled corticosteroids, a minority remains symptomatic despite maximal standard-of-care therapy and constitutes a significant unmet medical need. A growing number of investigational therapeutics under clinical development for asthma are biologic therapies that specifically target mediators of type 2 airway inflammation. In this chapter, we consider the biological functions of therapeutic targets in asthma and data from clinical trials of biologic agents directed against these targets. We discuss recent clinical trial results in terms of four key components of drug development: target selection, molecule selection, outcome selection, and patient selection, with particular attention paid to the emerging role of biomarkers in clinical development for asthma.

Concomitant asthma medications in moderate-to-severe allergic asthma treated with omalizumab

BACKGROUND

Omalizumab is a recombinant humanized monoclonal anti-IgE antibody approved in adults and adolescents with moderate-to-severe persistent allergic asthma inadequately controlled with inhaled corticosteroids (ICS). EXCELS is an ongoing prospective observational cohort study of approximately 5000 omalizumab-treated and >2800 non-omalizumab-treated patients aged ≥12 years.

OBJECTIVE

We evaluated concomitant medication use changes (total ICS dose [including monotherapy and combination therapy, fluticasone equivalent], short-acting beta-agonists [SABA], and leukotriene modifier [LTM]) over 2 years among subsets of patients enrolled in EXCELS.

METHODS

Patient subsets included "new starts" (omalizumab initiated at baseline [n = 549], "established users" (omalizumab initiated >7 days before baseline [n = 4421]), and "non-omalizumab" patients (not treated with omalizumab [n = 2867]).

RESULTS

At baseline, mean ± SD total daily ICS doses were 680 ± 414 μg/d in new starts, 642 ± 431 μg/d in established users, and 548 ± 382 μg/d in non-omalizumab patients. From baseline through year 2, total ICS dose decreased in 65% of new starts (mean ± SD change, -393 ± 504 μg/d), 57% of established users (-287 ± 492 μg/d), and 54% of non-omalizumab patients (-232 ± 431 μg/d). At baseline, SABA use for new starts, established users, and non-omalizumab patients was 1.9, 1.3, and 1.4 puffs/d, respectively. At year 2, SABA use decreased in 65% of new starts, 55% of established users, and 54% of non-omalizumab patients. At year 2, LTM dose decreased in 52% of new starts, 44% of established users, and 40% of non-omalizumab patients.

CONCLUSION

Omalizumab therapy initiation was associated with decreased doses of ICS, SABA, and LTM over 2 years of follow-up for the majority of patients in a "real-world" cohort study of moderate-to-severe allergic asthma patients.

Off-label use of omalizumab in non-asthma conditions: new opportunities

Allergic diseases are mediated by IgE and, hence, neutralizing IgE to attenuate type I hypersensitivity reactions may result in clinical benefits. This has been mainly established in several large pre- and postmarketing studies of the humanized monoclonal anti-IgE antibody, omalizumab, in patients with allergic asthma. In this patient population, omalizumab has been shown to have beneficial effects in subjective and objective outcome measures, as well as resulting in reductions in medication use. Omalizumab is now globally licensed for use in severe persistent asthma. However, a growing number of reports suggest that anti-IgE treatment may also be beneficial to patients suffering from other IgE-related conditions, including allergic rhinitis, peanut allergy, latex sensitivity, atopic dermatitis, chronic urticaria and allergic bronchopulmonary aspergillosis. For these patients, and specifically for those with severe refractory disease, anti-IgE treatments might have the potential of reducing their financial burden both in terms of medical costs and of loss of productivity in missed work and school days. In this reveiw, we evaluate the evidence in support of a more extensive role for omalizumab in a number of non-asthma IgE-related conditions, and particularly where intensive treatment has not been effective. However, studies with larger numbers of well-characterized patients will be necessary to provide sound evidence regarding the benefit of IgE blockade in these challenging conditions.

The asthma disease activity score: a discriminating, responsive measure predicts future asthma attacks

BACKGROUND

Classifying asthma severity or activity has evolved, but there are no published weighted composite measures of asthma disease activity that account for the relative importance of the many individual clinical variables that are widely used.

OBJECTIVES

We sought to develop a weighted and responsive measure of asthma disease activity.

METHODS

Discriminant and multiple regression analyses based on 2 previously conducted clinical trials were used to develop the Asthma Disease Activity Score (ADAS-6).

RESULTS

The ADAS-6 demonstrated content validity because its components assess different manifestations of asthma: FEV(1) (percent predicted), Asthma Quality of Life Questionnaire-Symptom domain, rescue β-agonist use, nocturnal awakenings, peak expiratory flow diurnal variability, and rescue β-agonist use diurnal variability. The ADAS-6 demonstrated cross-sectional and longitudinal validity. It was discriminating: it distinguished levels of disease activity and response to different treatment intensities (P < .0001). Similar results were obtained with an independent clinical trial. The ADAS-6 was highly responsive to treatment effects, with a standardized effect size exceeding that of other widely used outcome measures. Using ADAS-6 as the primary end point in the montelukast pivotal trials would have significantly reduced the sample size needed to detect a comparable change in outcome. Furthermore, increments in the ADAS-6 predicted the risk of future asthma attacks. A simplified Asthma Disease Activity Score 4-variable version (ADAS-4) demonstrated similar measurement properties.

CONCLUSIONS

The ADAS-6 and ADAS-4 are novel, weighted, and responsive measures of asthma disease activity. Use of these measures in clinical trials might better separate treatment effects, predict future asthma attacks, and substantially reduce sample size.

Longitudinal changes in asthma control with omalizumab: 2-year interim data from the EXCELS Study

BACKGROUND

Asthma guidelines emphasize the importance of achieving and maintaining asthma control; however, many patients with moderate to severe asthma fail to achieve adequate control.

OBJECTIVE

This 2-year interim analysis evaluated the longitudinal effects of omalizumab on asthma control in patients treated in real-world clinical practice settings.

METHODS

EXCELS is an ongoing observational cohort study of approximately 5000 omalizumab-treated and 2500 non-omalizumab-treated patients aged ≥12 years with moderate to severe asthma. Asthma control was measured using the Asthma Control Test (ACT) every 6 months.

RESULTS

Subgroups of the omalizumab cohort included those who initiated omalizumab at baseline (new starts, n = 549) and those treated with omalizumab >7 days before baseline (established users, n = 4421). For reference, data are also presented for patients who were not receiving omalizumab prior to or at the time of enrolment (non-omalizumab, n = 2867). Over half of the new starts (54%) achieved improvement in ACT consistent with the minimally important difference (MID, defined as ≥3-point improvement) by Month 6 and this proportion increased throughout the follow-up period, reaching 62% at Month 24. Similar results were observed in patients stratified by moderate and severe asthma. Established users of omalizumab maintained asthma control throughout the observation period.

CONCLUSION

Over a 2-year period, patients initiating omalizumab therapy experienced clinically relevant improvements in asthma control, which were maintained during 2 years of longitudinal follow-up. Established users of omalizumab maintained asthma control over the 2-year period with a small improvement similar to that seen in non-omalizumab users.

A 36-month study on the cost/utility of add-on omalizumab in persistent difficult-to-treat atopic asthma in Italy

OBJECTIVE

Omalizumab is a biological treatment for difficult-to-treat allergic asthma. Its mechanism of action relies on impeding the binding of immunoglobulin E (IgE) to specific cellular receptors, thus blocking the inflammatory cascade. At present, no long-term data are available on its cost/effectiveness. The aim of this study is to assess long-term clinical outcomes and to measure the cost/utility of long-term omalizumab use in difficult-to-treat allergic asthmatics.

METHODS

The clinical, economic, and quality-of-life (QoL) outcomes of 36-month add-on omalizumab therapy were compared to equivalent outcomes for the year before the therapy's introduction in a cohort (n = 16) of adults with severe uncontrolled atopic asthma on chronic high-dose antiasthma treatments. The variables considered were lung function, IgE levels, health status, Asthma Control Test (ACT) score, QoL (St. George Questionnaire), general practitioner (GP) and specialist visits, number and duration of hospitalizations, emergency room admission, and pharmacological treatment (both dose and duration). Derived calculated indicators were changes in health-related QoL, total healthcare costs, and incremental cost/utility. Data from the two periods were tested for statistically significant differences according to Student's t test and p < .05 was accepted.

RESULTS

Add-on omalizumab significantly and progressively improved asthma control and patient health-related QoL. Symptomatic drug and hospital care costs for these patients dropped significantly. A €450 increase in overall monthly costs was observed; however, when health benefits were considered, this cost increase translated into an incremental cost/utility ratio of €23,880 per quality-adjusted life year gained, which is quite a favorable and convenient figure in terms of the willingness to pay for health benefits in industrialized countries.

CONCLUSIONS

The 36-month add-on omalizumab therapy persistently improved all clinical outcomes in difficult-to-treat asthmatic patients. Costs were also optimized and related to the extent of long-term health benefits achieved.

Steroid-resistant asthma

Steroid-resistant asthma (SRA) refers to patients with symptoms consistent with asthma who show very poor or no response at all to high doses of inhaled or even of systemic corticosteroids. The current article reviews the SRA related literature focusing on the problems associated with the definition of SRA (especially its association with difficult to control, or severe asthma), its various phenotypes, its molecular basis, and the potential treatment options. The article also discusses the limitations of some of the key criteria used for the determination of SRA and proposes a modified set of criteria that are more applicable to children.