Inhibition of allergic reactions with antibodies to IgE

Biologic Therapies for Asthma and Allergic Disease: Past, Present, and Future

The discovery of the mechanism underlying allergic disease, mouse models of asthma, and bronchoscopy studies provided initial insights into the role of Th2-type cytokines, including interlukin (IL)-4, IL-5 and IL-13, which became the target of monoclonal antibody therapy. Omalizumab, Benralizumab, Mepolizumab, Reslizumab, and Tezepelumab have been approved. These biologicals have been shown to be good alternative therapies to corticosteroids, particularly in severe asthma management, where they can improve the quality of life of many patients. Given the success in asthma, these drugs have been used in other diseases with type 2 inflammation, including chronic rhinosinusitis with nasal polyps (CRSwNP), atopic dermatitis, and chronic urticaria. Like the Th2-type cytokines, chemokines have also been the target of novel monoclonal therapies. However, they have not proved successful to date. In this review, targeted therapy is addressed from its inception to future applications in allergic diseases.

Is Omalizumab Related to Ear and Labyrinth Disorders? A Disproportionality Analysis Based on a Global Pharmacovigilance Database

Introduction: Asthma is a chronic disease, characterized by reversible airway obstruction, hypersensitivity reactions, and inflammation. Oral corticosteroids are an important treatment option for patients with severe or steroid-resistant asthma. Biologics for asthma are recommended in patients with severe asthma, owing to their steroid-sparing effect as well as their ability to reduce the severity and aggravation of uncontrolled asthma. Most clinical trials of omalizumab in patients with asthma have suggested its tolerability and safety. However, some studies reported eosinophilic comorbidities in the ear, nose, and throat during omalizumab treatment, particularly eosinophilic otitis media. This study examined the relationship between ear disorders and omalizumab compared with that of other biologics for asthma using a large real-world database. Materials and Methods: Individual case safety reports from the Uppsala Monitoring Centre Vigibase of biologics for asthma (omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab) up to 29 December 2019, were used. A disproportionality analysis was performed using the proportional reporting ratio (PRR), reporting odds ratio (ROR), and information components (IC). A hierarchy analysis used the Medical Dictionary for Regulatory Activities Terminology. A tree map was generated using R studio version 4.2. Results: In 32,618 omalizumab reports, 714 adverse events (AEs) were detected as signals. Among the 714 signals, seventeen AEs were detected as signals of omalizumab-related ear and labyrinth disorders in 394 reports. Only three AEs (ear pain, ear disorder, and ear discomfort) were detected from mepolizumab. No signal was detected from reslizumab, benralizumab, and dupilumab. Conclusions: Careful monitoring of ear disorders is recommended when omalizumab treatment is started, with decreased oral corticosteroid use in patients with severe asthma. Further studies are necessary to confirm the omalizumab-related signals.

Anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis

BACKGROUND

Cystic fibrosis is an autosomal recessive multisystem disorder with an approximate prevalence of 1 in 3500 live births. Allergic bronchopulmonary aspergillosis is a lung disease caused by aspergillus-induced hypersensitivity with a prevalence of 2% to 15% in people with cystic fibrosis. The mainstay of treatment includes corticosteroids and itraconazole. The treatment with corticosteroids for prolonged periods of time, or repeatedly for exacerbations of allergic bronchopulmonary aspergillosis, may lead to many adverse effects. The monoclonal anti-IgE antibody, omalizumab, has improved asthma control in severely allergic asthmatics. The drug is given as a subcutaneous injection every two to four weeks. Since allergic bronchopulmonary aspergillosis is also a condition resulting from hypersensitivity to specific allergens, as in asthma, it may be a candidate for therapy using anti-IgE antibodies. Therefore, anti-IgE therapy, using agents like omalizumab, may be a potential therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis. This is an updated version of the review.

OBJECTIVES

To evaluate the efficacy and adverse effects of anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews. Last search: 09 September 2021. We searched two ongoing trial registries (Clinicaltrials.gov and the WHO trials platform). Date of latest search: 16 August 2021.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing anti-IgE therapy to placebo or other therapies for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias in the included study. They planned to perform data analysis using Review Manager.

MAIN RESULTS

Only one study enrolling 14 participants was eligible for inclusion in the review. The double-blind study compared a daily dose of 600 mg omalizumab or placebo along with twice daily itraconazole and oral corticosteroids, with a maximum daily dose of 400 mg. Treatment lasted six months but the study was terminated prematurely and complete data were not available. We contacted the study investigator and were told that the study was terminated due to the inability to recruit participants into the study despite all reasonable attempts. One or more serious side effects were encountered in six out of nine (66.67%) and one out of five (20%) participants in omalizumab group and placebo group respectively.

AUTHORS' CONCLUSIONS

There is lack of evidence for the efficacy and safety of anti-IgE (omalizumab) therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis. There is a need for large prospective randomized controlled studies of anti-IgE therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis with both clinical and laboratory outcome measures such as steroid requirement, allergic bronchopulmonary aspergillosis exacerbations and lung function.

Asthma in pregnancy: An update

AIM

To update obstetric care providers about asthma management.

SUMMARY

Asthma is the most frequent comorbid chronic illness in pregnancy. Convincing evidence shows that uncontrolled asthma magnifies the risk of maternal, fetal and neonate complications. Unfortunately, one in four women take no inhaler during pregnancy, and it is likely that decreased adherence, rather than changes in pathology, explains uncontrolled maternal asthma. Patient surveys reveal a need for information and reassurance. Although some molecules are preferred in pregnancy, there is currently no basis to withhold any asthma medication - old or new. Biomarkers such as blood eosinophils and fractional exhaled nitric oxide are an effective way to assess the risk of asthma attacks and the likelihood of responding to inhaled steroids. Furthermore, practice-changing trials in mild asthma show that switching reliever-only regimens to as-needed 'controller-and-reliever' therapy is effective. We suggest that applying these changes can alleviate women's concerns and improve outcomes.

Emerging concepts and directed therapeutics for the management of asthma: regulating the regulators

Asthma is a common, heterogeneous and serious disease, its prevalence has steadily risen in most parts of the world, and the condition is often inadequately controlled in many patients. Hence, there is a major need for new therapeutic approaches. Mild-to-moderate asthma is considered a T-helper cell type-2-mediated inflammatory disorder that develops due to abnormal immune responses to otherwise innocuous allergens. Prolonged exposure to allergens and persistent inflammation results in myofibroblast infiltration and airway remodelling with mucus hypersecretion, airway smooth muscle hypertrophy, and excess collagen deposition. The airways become hyper-responsive to provocation resulting in the characteristic wheezing and obstructed airflow experienced by patients. Extensive research has progressed the understanding of the underlying mechanisms and the development of new treatments for the management of asthma. Here, we review the basis of the disease, covering new areas such as the role of vascularisation and microRNAs, as well as associated potential therapeutic interventions utilising reports from animal and human studies. We also cover novel drug delivery strategies that are being developed to enhance therapeutic efficacy and patient compliance. Potential avenues to explore to improve the future of asthma management are highlighted.

Add-On Omalizumab for Inadequately Controlled Severe Pollinosis Despite Standard-of-Care: A Randomized Study

BACKGROUND

Cedar pollinosis (CP), a common form of seasonal allergic rhinitis (AR), is a substantial medical problem in Japan due to its high prevalence and severe symptoms. Omalizumab (anti-IgE therapy) has previously proven to be effective in CP/AR, but no studies for inadequately controlled severe CP/AR despite standard-of-care (SoC) have been conducted.

OBJECTIVE

To determine the efficacy of omalizumab added to SoC in patients with inadequately controlled severe CP in a randomized, double-blinded, placebo-controlled, phase III study.

METHODS

Adult/adolescent patients with severe CP whose symptoms were inadequately controlled despite nasal corticosteroids plus 1 or more oral medications in the previous 2 seasons were randomized to receive omalizumab (n = 162) or placebo (n = 175). All patients received concomitant antihistamines and nasal corticosteroids as SoC. The primary endpoint was the mean nasal symptom score during the severe symptom period. Secondary endpoints included mean ocular symptom score, quality of life (QoL), and safety.

RESULTS

The SoC + omalizumab treatment had statistically significantly and clinically important lower nasal (least squares mean difference, -1.03, P < .001) and ocular (-0.87, P < .001) symptom scores compared with SoC + placebo, respectively. Differences in scores for individual components of nasal and ocular symptoms were also statistically and clinically significant. SoC + omalizumab also improved QoL scores as overall and in all domains. No unexpected safety signals were observed.

CONCLUSIONS

In patients with severe CP, omalizumab added to SoC demonstrated consistent efficacy in improving symptoms and QoL, and was well tolerated. These results indicate that omalizumab could be a promising therapeutic option for severe CP/AR.

Development and validation of a new IgE-Tolerant ELISA method for quantifying serum concentration of omalizumab

BACKGROUND

Omalizumab is effectively used in asthma therapy, but ELISA methods used for omalizumab determination in blood from asthma patients may be interfered by the pre-existing IgE.

OBJECTIVE

To reduce the effect of pre-existing IgE on the omalizumab determination, the authors proposed a novel ELISA that can eliminate pre-existing IgE with by acid dissociation.

METHOD

The method was developed by dissociating the IgE-omalizumab complex with glacial acetic acid, and bio-IgE was added to bind the free omalizumab in serum, then bio-IgE-complex was captured by the immobilized streptavidin and detected by HRP-conjugated mouse anti-human IgG. Then a full validation of standard curve fitness, precision, accuracy, dilutional linearity, specificity, selectivity, stability, hook effect, and parallelism was performed. At last, the method was used in two studies in compliance with Good Laboratory Practice.

RESULTS

Correlation coefficient R² obtained from each calibration curve was 0.999 or 1.000 in the detection range of 0.1 μg/mL to 12.8 μg/mL. Results of precision, accuracy, dilutional linearity, specificity, selectivity, stability, hook effect, and parallelism were acceptable according to the ICH guideline M10. The method was successfully used in omalizumab determination in serum from 20 monkeys treated with 150 mg/kg omalizumab.

CONCLUSIONS

In conclusion, by dissociating IgE-omalizumab complex, the authors proposed for the first time a new validated IgE-tolerant ELISA assay to determine omalizumab concentration in serum samples.

Anti-IgE treatment in allergic rhinitis

OBJECTIVES

To review the efficacy of anti-IgE therapy in allergic rhinitis (AR).

METHODS

Literature search was performed using the PubMed and Proquest Central databases at Kırıkkale University Library.

RESULTS

Although the skin prick testing in patients suffering from AR is positive (indicating that antigen-specific Immunoglobulin E has been produced), there is no association with overall circulating IgE levels. Correlation was lacking between circulating IgE level and either skin prick tests or laboratory testing for specific IgE. Omalizumab binds to uncomplexed IgE in man more avidly than does Fc-epsilon. The effect of omalizumab is to lower the level of IgE and downgrade production of FceRI receptors (which bind IgE) in mast cells and basophils, causing less mast cell recruitment and responsivity and thus diminishing eosinophilic infiltration and activation. Anti-IgE therapy through omalizumab may shorten the lifetime of mast cells and causes dendritic cells to downgrade their production of FcεRI. There are reports indicating benefit from omalizumab in managing food allergies, nasal polyp formation, essential anaphylaxis, AR, venom allergy and eczema. Omalizumab acts to lessen circulating IgE levels, whilst reducing production of FceRI by mast cells and basophils. The fact that omalizumab influences how eosinophils respond may be down to disruption of the antigen-IgE-mast cell interactions, with mast cells being recruited at lower levels and thus chemotactic eosinophilic recruitment via cytokines being greatly reduced. Omalizumab has the effect in cases of perennial AR of blocking the increased eosinophilic recruitment and tissue infiltration initiated by seasonal antigens. Likewise, in omalizumab-treated cases, circulating unbound IgE levels showed significant decreases. For patients with perennial AR, the average daily nasal severity score was significantly reduced where omalizumab was administered, compared to placebo.

CONCLUSION

Omalizumab has efficacy in ameliorating symptoms and reduces the necessity for additional medication in both seasonal and perennial allergic rhinitis.

Immunological and hematological effects of IL-5(Rα)-targeted therapy: An overview

IL‐5 is an important cytokine for priming and survival of mature eosinophils and for proliferation and maturation of their progenitors. Hence, IL‐5(Rα) targeting will be increasingly used in diseases where eosinophils are the key immune effector cells such as eosinophilic asthma (EA), hypereosinophilic syndrome (HES), eosinophilic esophagitis (EE), and eosinophilic granulomatosis with polyangiitis (EGPA). Therefore, several neutralizing monoclonal antibodies directed against IL‐5 (mepolizumab and reslizumab) and its receptor IL‐5Rα (benralizumab) have found or will find their way to the clinic. While the clinical effect of these drugs has been extensively investigated and reviewed, the understanding of the underlying immunological and hematological mechanisms remains less clear. This review will discuss the translational outcomes of treatment with these monoclonal antibodies in humans to shed light on the mechanisms underlying the main immunological and hematological findings from these clinical trials in humans.

The effect of omalizumab treatment on IgE and other immunoglobulin levels in patients with chronic spontaneous urticaria and its association with treatment response

Introduction

Suppression of free immunoglobulin E (IgE) levels and an increase in total IgE levels are observed during omalizumab treatment. However, whether omalizumab has any effect on other immunoglobulins is unknown.

Aim

To investigate the effect of omalizumab treatment on serum IgE and other immunoglobulins, and demonstrate any association with response to treatment in patients with chronic spontaneous urticaria (CSU).

Material and methods

The study included 41 patients diagnosed with CSU. Baseline and post-12-week-treatment total IgE, IgA, IgM, and IgG levels and blood eosinophil, neutrophil, lymphocyte and platelet levels were compared. Patients were grouped based on weekly urticaria activity score (UAS-7) responses and these parameters were compared.

Results

There was a significant increase in baseline and post-12-week-treatment total IgE levels, while there was no significant difference in other immunoglobulin levels. A significant reduction was found in neutrophil counts after the treatment, whereas there was no significant difference in eosinophil, lymphocyte and platelet levels. There was no difference in these parameters between groups with complete response and without complete response.

Conclusions

Omalizumab treatment can also be used in patients with immunoglobulin deficiency. Due to the observed reduction in neutrophil counts after the treatment, patients must be closely followed for whole blood parameters.

Antibody therapy for the management of severe asthma with eosinophilic inflammation

One of the characteristic features of asthma is chronic airway inflammation typically with eosinophil infiltration. Most asthmatics can be treated successfully with conventional treatment appropriate for their severity, but in some severe cases, asthma cannot be well controlled even with thorough treatment and this condition is known as 'refractory asthma'. To overcome severe refractory asthma, a new therapeutic strategy with biologics has been developed based on the knowledge of molecular mechanisms of airway inflammation in asthma, induced by the condition of high Th2-type responses and activation of eosinophils as well as allergic reactions. Humanized anti-human IgE antibody (anti-IgE; omalizumab) was the first biological preparation approved for treating asthma. Based on clinical evidence, treatment with anti-IgE (anti-IgE therapy) has been accepted as a new therapeutic approach for severe allergic asthma in adults since 2009 and in children since 2012 and has been shown to have ~60% efficacy. More recently, a humanized anti-IL-5 antibody (anti-IL-5; mepolizumab) was launched in June 2016 and has attracted great interest due to its potential effects. Several clinical studies are also ongoing to evaluate the biological preparations targeting IL-5 receptor α (IL-5Rα), IL-4 receptor α (IL-4Rα), which is shared by IL-4 and IL-13, thymic stromal lymphopoietin (TSLP) and IL-33. The new strategy with biologics targeting eosinophilic airway inflammation might open a new array for us to overcome severe refractory asthma in the future.

Anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis

BACKGROUND

Cystic fibrosis is an autosomal recessive multisystem disorder with an approximate prevalence of 1 in 3500 live births. Allergic bronchopulmonary aspergillosis is a lung disease caused by aspergillus-induced hypersensitivity with a prevalence of 2% to 15% in people with cystic fibrosis. The mainstay of treatment includes corticosteroids and itraconazole. The treatment with corticosteroids for prolonged periods of time, or repeatedly for exacerbations of allergic bronchopulmonary aspergillosis, may lead to many adverse effects. The monoclonal anti-IgE antibody, omalizumab, has improved asthma control in severely allergic asthmatics. The drug is given as a subcutaneous injection every two to four weeks. Since allergic bronchopulmonary aspergillosis is also a condition resulting from hypersensitivity to specific allergens, as in asthma, it may be a candidate for therapy using anti-IgE antibodies. Therefore, anti-IgE therapy, using agents like omalizumab, may be a potential therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis. This is an updated version of the review.

OBJECTIVES

To evaluate the efficacy and adverse effects of anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews. Last search: 29 September 2017.We searched two ongoing trial registries (Clinicaltrials.gov and the WHO trials platform). Date of latest search: 24 January 2018.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing anti-IgE therapy to placebo or other therapies for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias in the included study. They planned to perform data analysis using Review Manager.

MAIN RESULTS

Only one study enrolling 14 participants was eligible for inclusion in the review. The double-blind study compared a daily dose of 600 mg omalizumab or placebo along with twice daily itraconazole and oral corticosteroids, with a maximum daily dose of 400 mg. Treatment lasted six months but the study was terminated prematurely and complete data were not available. We contacted the study investigator and were told that the study was terminated due to the inability to recruit participants into the study despite all reasonable attempts. One or more serious side effects were encountered in six out of nine (66.67%) and one out of five (20%) participants in omalizumab group and placebo group respectively.

AUTHORS' CONCLUSIONS

There is lack of evidence for the efficacy and safety of anti-IgE (omalizumab) therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis. There is a need for large prospective randomized controlled studies of anti-IgE therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis with both clinical and laboratory outcome measures such as steroid requirement, allergic bronchopulmonary aspergillosis exacerbations and lung function.

Trapping IgE in a closed conformation by mimicking CD23 binding prevents and disrupts FcεRI interaction

Anti-IgE therapeutics interfere with the ability of IgE to bind to its receptors on effector cells. Here we report the crystal structure of an anti-IgE single-domain antibody in complex with an IgE Fc fragment, revealing how the antibody inhibits interactions between IgE and the two receptors FcεRI and CD23. The epitope overlaps only slightly with the FcεRI-binding site but significantly with the CD23-binding site. Solution scattering studies of the IgE Fc reveal that antibody binding induces a half-bent conformation in between the well-known bent and extended IgE Fc conformations. The antibody acts as functional homolog of CD23 and induces a closed conformation of IgE Fc incompatible with FcεRI binding. Notably the antibody displaces IgE from both CD23 and FcεRI, and abrogates allergen-mediated basophil activation and facilitated allergen binding. The inhibitory mechanism might facilitate strategies for the future development of anti-IgE therapeutics for treatment of allergic diseases.

IgE is linked to allergic diseases and there is a great interest in developing anti-IgE therapeutics. Here the authors characterize the binding of human IgE Fc to a single domain antibody (sdab) and show that the sdab induces a closed conformation, which prevents and disrupts IgE binding to its receptor FcεRI and abrogates allergen mediated activation.

Mechanisms of action that contribute to efficacy of omalizumab in chronic spontaneous urticaria

The monoclonal anti-immunoglobulin E (IgE) antibody, omalizumab, was the first drug approved for use in patients with chronic idiopathic/spontaneous urticaria (CIU/CSU) who remain symptomatic despite H₁ -antihistamine treatment. Omalizumab binds to free IgE, which lowers free IgE levels and causes FcεRI receptors on basophils and mast cells to be downregulated. It has been shown to improve symptoms of CIU/CSU, but its mechanism of action is not currently understood. Potential mechanisms in CIU/CSU include reducing mast cell releasability, reversing basopenia and improving basophil IgE receptor function, reducing activity of IgG autoantibodies against FcεRI and IgE, reducing activity of IgE autoantibodies against an antigen or autoantigen that has yet to be definitively identified, reducing the activity of intrinsically 'abnormal' IgE, and decreasing in vitro coagulation abnormalities associated with disease activity. However, none of these theories alone or in combination fully account for the pattern of symptom improvement seen with omalizumab therapy, and therefore, no one mechanism is likely to be the definitive mechanism of action. Additional research is needed to further clarify the involvement of omalizumab in relieving symptoms associated with the complex, multifactorial pathogenesis of CIU/CSU.

Biologics in asthma--the next step toward personalized treatment

Asthma is a multifaceted disease and is associated with significant impairment and risk, and a therapeutic response that is highly variable. Although current treatments are usually effective for patients with mild-to-moderate disease, patients with more severe asthma are often unresponsive to current efforts, and there remains a need for agents with properties that may achieve control in these individuals. There is ongoing research to identify bioactive molecules that contribute to the pathophysiology of asthma, and many of these have been identified as potential therapeutic targets to improve control of this disease. As a consequence of these efforts, monoclonal antibodies have been developed and tested as to their effectiveness in the treatment of asthma. The assessment of these new treatments has identified particular pathways that, in selected patients, have shown benefit. The following review will discuss the current and future use of biological agents for the treatment of asthma, their efficacy, and how certain patient phenotypes and endotypes may be associated with biomarkers that may be used to select treatments to achieve greatest effectiveness of their use. As knowledge of the effects of these biological agents in asthma emerges, as well as the patients in whom they are most beneficial, the movement toward personalized treatment will follow.

Anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis

BACKGROUND

Cystic fibrosis is an autosomal recessive multisystem disorder with an approximate prevalence of 1 in 3500 live births. Allergic bronchopulmonary aspergillosis is a lung disease caused by aspergillus-induced hypersensitivity with a prevalence of 2% to 15% in people with cystic fibrosis. The mainstay of treatment includes corticosteroids and itraconazole. The treatment with corticosteroids for prolonged periods of time, or repeatedly for exacerbations of allergic bronchopulmonary aspergillosis, may lead to many adverse effects. The monoclonal anti-IgE antibody, omalizumab, has improved asthma control in severely allergic asthmatics. The drug is given as a subcutaneous injection every two to four weeks. Since allergic bronchopulmonary aspergillosis is also a condition resulting from hypersensitivity to specific allergens, as in asthma, it may be a candidate for therapy using anti-IgE antibodies. Therefore, anti-IgE therapy, using agents like omalizumab, may be a potential therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis. This is an updated version of the review.

OBJECTIVES

To evaluate the efficacy and adverse effects of anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews. Last search: 27 July 2015.We searched the ongoing trial registry clinicaltrials.gov for any ongoing trials. Latest search for clinicaltrials.gov: 23 October 2015.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing anti-IgE therapy to placebo or other therapies for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias in the included study. They planned to perform data analysis using Review Manager.

MAIN RESULTS

Only one study enrolling 14 participants was eligible for inclusion in the review. The double-blind study compared a daily dose of 600 mg omalizumab or placebo along with twice daily itraconazole and oral corticosteroids, with a maximum daily dose of 400 mg. Treatment lasted six months but the study was terminated prematurely and complete data were not available. We contacted the study investigator and were told that the study was terminated due to the inability to recruit participants into the study despite all reasonable attempts. One or more serious side effects were encountered in six out of nine (66.67%) and one out of five (20%) participants in omalizumab group and placebo group respectively.

AUTHORS' CONCLUSIONS

There is lack of evidence for the efficacy and safety of anti-IgE (omalizumab) therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis. There is a need for large prospective randomized controlled studies of anti-IgE therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis with both clinical and laboratory outcome measures such as steroid requirement, allergic bronchopulmonary aspergillosis exacerbations and lung function.

Structure of the omalizumab Fab

Omalizumab is a humanized anti-IgE antibody that inhibits the binding of IgE to its receptors on mast cells and basophils, thus blocking the IgE-mediated release of inflammatory mediators from these cells. Omalizumab binds to the Fc domains of IgE in proximity to the binding site of the high-affinity IgE receptor FcℇRI, but the epitope and the mechanisms and conformations governing the recognition remain unknown. In order to elucidate the molecular mechanism of its anti-IgE activity, the aim was to analyse the interaction of omalizumab with human IgE. Therefore, IgE Fc Cℇ2-4 was recombinantly produced in mammalian HEK-293 cells. Functionality of the IgE Fc was proven by ELISA and mediator-release assays. Omalizumab IgG was cleaved with papain and the resulting Fab was purified by ion-exchange chromatography. The complex of IgE Fc with omalizumab was prepared by size-exclusion chromatography. However, crystals containing the complex were not obtained, suggesting that the process of crystallization favoured the dissociation of the two proteins. Instead, two structures of the omalizumab Fab with maximum resolutions of 1.9 and 3.0 Å were obtained. The structures reveal the arrangement of the CDRs and the position of omalizumab residues known from prior functional studies to be involved in IgE binding. Thus, the structure of omalizumab provides the structural basis for understanding the function of omalizumab, allows optimization of the procedure for complex crystallization and poses questions about the conformational requirements for anti-IgE activity.

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.

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.

Anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis

BACKGROUND

Cystic fibrosis is an autosomal recessive multisystem disorder with an approximate prevalence of 1 in 3500 live births. Allergic bronchopulmonary aspergillosis is a lung disease caused by aspergillus-induced hypersensitivity with a prevalence of 2% to 15% in people with cystic fibrosis. The mainstay of treatment includes corticosteroids and itraconazole. The treatment with corticosteroids for prolonged periods of time, or repeatedly for exacerbations of allergic bronchopulmonary aspergillosis, may lead to many adverse effects. The monoclonal anti-IgE antibody, omalizumab, has improved asthma control in severely allergic asthmatics. The drug is given as a subcutaneous injection every two to four weeks. Since allergic bronchopulmonary aspergillosis is also a condition resulting from hypersensitivity to specific allergens, as in asthma, it may be a candidate for therapy using anti-IgE antibodies. Therefore, anti-IgE therapy, using agents like omalizumab, may be a potential therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

OBJECTIVES

To evaluate the efficacy and adverse effects of anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews. Last search: 21 January 2013.We searched the ongoing trial registry clinicaltrials.gov for any ongoing trials. Latest search for clinicaltrials.gov: 22 February 2013.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing anti-IgE therapy to placebo or other therapies for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias in the included study. They planned to perform data analysis using Review Manager 5.1.

MAIN RESULTS

Only one trial enrolling 14 patients was eligible for inclusion in the review. The study was terminated prematurely and complete data were not available. We contacted the study investigator and were told that the study was terminated due to the inability to recruit patients into the study despite all reasonable attempts. One or more serious side effects were encountered in six out of nine (66.67%) and one out of five (20%) patients in omalizumab group and placebo group respectively.

AUTHORS' CONCLUSIONS

There is lack of evidence for the efficacy and safety of anti-IgE (omalizumab) therapy in patients with cystic fibrosis and allergic bronchopulmonary aspergillosis. There is a need for large prospective randomized controlled trials of anti-IgE therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis with both clinical and laboratory outcome measures such as steroid requirement, allergic bronchopulmonary aspergillosis exacerbations and lung function.

Omalizumab and hypersensitivity reactions

PURPOSE OF REVIEW

Omalizumab, a monoclonal anti-IgE antibody, is currently indicated for the treatment of moderate-to-severe allergic asthma. We have reviewed the published studies and case reports of off-label omalizumab use in the prevention of IgE-mediated hypersensitivity reactions of various causes. Additionally, we have reviewed anaphylaxis associated with omalizumab treatment.

RECENT FINDINGS

Many case reports and smaller studies have reported the efficacy of omalizumab in the prevention of various hypersensitivity and anaphylactic reactions with or without known trigger. One randomized study has showed partial improvement in the tolerance of peanuts in peanut-allergic patients with anti-IgE therapy. Furthermore, several randomized, placebo-controlled studies and case reports have demonstrated that omalizumab in combination with allergen or venom immunotherapy decreases the incidence of systemic hypersensitivity reactions and may improve the clinical outcomes. Finally, review of the data documents low risk of anaphylaxis with omalizumab use, with one study demonstrating successful desensitization to this medication.

SUMMARY

The available studies indicate that omalizumab is effective and well tolerated in decreasing hypersensitivity reactions associated with allergen immunotherapy in patients with allergic rhinitis and mild-to-moderate asthma. Additionally, omalizumab may represent a promising therapy of anaphylaxis with or without known trigger, which should be further investigated with randomized studies. Moreover, additional research is needed to elucidate the mechanism of anaphylaxis with the medication itself.

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).

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.

Using the allergic immune system to target cancer: activity of IgE antibodies specific for human CD20 and MUC1

Monoclonal antibodies are widely used in the treatment of many B cell lymphomas and certain solid tumors. All currently approved therapeutic monoclonal antibodies are of the immunoglobulin G (IgG) isotype. We hypothesized that tumor-specific monoclonal antibodies of the IgE isotype may serve as effective cancer therapeutics. To test this hypothesis, we produced mouse-human chimeric IgE antibodies specific for the human B cell antigen CD20 and the epithelial antigen MUC1. We demonstrate here that anti-hCD20 IgE antibodies have in vitro cytotoxic activity when used with purified allergic effector cells derived from umbilical cord blood. At an effector-tumor ratio of 2:1, mast cells and tumor-specific IgE induced a 2.5-fold increase in tumor cell death, as compared to control IgE. Similar results were observed when eosinophils were used as effector cells. In an in vivo murine model of breast carcinoma, administration of anti-hMUC1 IgE reduced the growth of MUC1(+) tumors by 25-30 % in hFcεRI transgenic mice. In contrast, local production of IgE and cytokines chemotactic for macrophages, eosinophils and mast cells led to complete tumor eradication. These results suggest that allergic effector cells activated by IgE and cell surface antigens have the capacity to induce tumor cell death in vitro and in vivo. The use of chimeric antibodies and hFcεRI transgenic mice will greatly enhance investigations in the nascent field of allergo-oncology.

Monoclonal antibodies for chronic refractory asthma and pipeline developments

Patients with severe asthma suffer persistent symptoms and/or frequent exacerbations despite high-intensity treatment. Their severe unrelenting symptoms have a huge impact on healthcare resources owing to frequent hospital admissions and requirement for intensive treatments. Consequently, there is an undeniable need for more-effective and safer medications. Expanding knowledge of innate and adaptive immune responses is leading to the development of novel therapies for severe asthma. Herein, we review efficacy and safety data from human clinical trials of monoclonal antibodies that are approved or under investigation for use in asthma. Future drug candidates directed at key targets and the specific role of monoclonal antibodies in distinctively targeted sub-populations of severe asthmatics will be also discussed.

Reduction of total IgE by targeted coengagement of IgE B-cell receptor and FcγRIIb with Fc-engineered antibody

BACKGROUND

Sequestration of IgE to prevent its binding to high-affinity IgE receptor FcεRI on basophils and mast cells is an effective therapy for allergic asthma. IgE production requires differentiation of activated IgE(+) B cells into plasma cells upon allergen sensitization. B-cell receptor signaling is suppressed by the inhibitory IgG Fc receptor FcγRIIb; therefore, we reasoned that a therapeutic antibody that coengages FcγRIIb and IgE B-cell receptor would not only sequester IgE but also suppress its production by blocking IgE(+) B-cell activation and differentiation to IgE-secreting plasma cells.

OBJECTIVE

To explore the effects of IgE sequestration versus IgE suppression by comparing omalizumab to FcγRIIb-optimized anti-IgE antibodies in humanized mouse models of immunoglobulin production.

METHODS

By using a murine anti-IgE antibody as a template, we humanized, increased IgE binding, and modified its Fc domain to increase affinity for FcγRIIb. We next compared effects of this antibody (XmAb7195) versus omalizumab on the secretion of IgE and other isotypes in human PBMC cultures and in PBMC-engrafted severe combined immunodeficiency mice.

RESULTS

Relative to omalizumab, XmAb7195 has a 5-fold higher affinity for human IgE and more than 400-fold higher affinity for FcγRIIb. In addition to sequestering soluble IgE, XmAb7195 inhibited plasma cell differentiation and consequent human IgE production through coengagement of IgE B-cell receptor with FcγRIIb. In PBMC-engrafted mice, XmAb7195 reduced total human IgE (but not IgG or IgM) levels by up to 40-fold relative to omalizumab.

CONCLUSION

XmAb7195 acts by IgE sequestration coupled with an FcγRIIb-mediated inhibitory mechanism to suppress the formation of IgE-secreting plasma cells and reduce both free and total IgE levels.

Monoclonal antibodies for the treatment of severe asthma

Patients with severe asthma have a significant unmet need with persistent symptoms and/or frequent exacerbations despite treatment with high-dose steroid and other currently available therapies. These patients are also at risk of developing steroid-related side effects, and their severe, unrelenting symptoms have a huge impact on health care resources due to frequent hospital admissions and requirement for intensive medication use. Consequently, a compelling need exists for more effective and safer pharmacotherapies to help them achieve adequate disease control. Recent novel therapies for severe asthma are now emerging, some of the most promising of which are monoclonal antibodies. Monoclonal antibodies represent a form of immunotherapy used in a wide variety of therapeutic roles. The spectrum of disease states in which monoclonal antibodies have been approved for therapeutic use now includes respiratory and allergic diseases. At present, only one drug is licensed for allergic asthmatics with severe disease, omalizumab. We review some of the currently available biologics that are approved or under investigation for use in severe asthma. Some have shown to be useful in specifically targeted subpopulations of patients with severe asthma, whereas other have proven to be unsafe and/or unsuccessful. Despite these developments, more effort should be devoted to identifying new molecular targets, testing innovative approaches, and establishing the best use of what is available. Regarding this latter point, identifying individual characteristics that predict successful responses to these treatments is highly desirable.

Mechanisms of IgE Inflammation

The prevalence of diseases such as allergic asthma and rhinitis continues to increase in the United States, affecting millions of people. It is well-established that allergy contributes to the pathogenesis of most asthma, especially in children and young adults. Despite current therapy (eg, inhaled corticosteroids, anti-leukotrienes, and bronchodilators), patients with moderate to severe asthma remain symptomatic and experience frequent exacerbations of disease requiring oral corticosteroids, emergency department treatments, and hospitalizations. Allergic diseases are traditionally referred to as immediate or type 1 hypersensitivity reactions, with IgE as a critical factor. IgE is involved in allergic inflammation, especially in early-phase response, but it may also be involved in the late-phase allergic response. A direct correlation between serum IgE levels and asthma exists. As logarithm IgE values increase, asthma prevalence increases linearly, even in patients who are categorized as having nonallergic asthma. In addition, there is a significant, although low association in allergic rhinitis with IgE levels and positive skin test reactivity to pollens. Recent advances in our understanding of the role of IgE in allergic inflammation have led to the development of a monoclonal antibody to IgE that reduces IgE levels, thereby reducing allergic inflammation. This review aims to provide an overview of the basic science of the IgE molecule and the clinical efficacy of anti-IgE therapy in allergic and asthmatic diseases.

Stratified medicine in selecting biologics for the treatment of severe asthma

PURPOSE OF REVIEW

Despite optimal treatment, asthma symptoms in about 5-10% of patients remain poorly controlled. Apart from having an impact on their asthma-related quality of life and adverse effects of the medications used (especially corticosteroids), their severe symptoms also impact healthcare resources due to frequent admission and requirement for intensive medications use. The last decade has seen an improved understanding in the pathophysiology of the complex cellular and molecular networks involved in the inflammatory and immunological phenotype of severe asthma. This knowledge may help providing strategies by which these phenotypes operate and pave the way for drug development and individualized treatment.

RECENT FINDINGS

Here we review the current evidence of biological agents in patients with severe asthma recently assessed for safety and efficacy. Some of these agents have shown to be useful in specifically targeted subpopulations of patients with severe asthma, whereas others have proven to be unsafe and/or unsuccessful. In addition, we discuss recent data on clinical and pharmacokinetic-pharmacodynamic aspects of omalizumab, the only licensed anti-IgE therapy for severe atopic asthma.

SUMMARY

More basic science work is required to improve the current understanding of severe asthma pathophysiology and proof-of-concept clinical studies are required to explore relevant biomolecular targets in this small subset of patients. At present, only one drug is licensed for allergic asthmatic patients with severe disease, omalizumab. Novel therapies in the form of oligonucleotide therapies and other biological agents are also being investigated in the difficult-to-treat asthmatic patient group.

A peptide binding to dimerized translationally controlled tumor protein modulates allergic reactions

Translationally controlled tumor protein (TCTP) is believed to be involved in a variety of inflammatory processes: secretion of histamine and cytokines such as IL-4, IL-8, IL-13, and granulocyte/macrophage colony-stimulating factor; chemoattraction for eosinophils; augmentation of B cell proliferation; and immunoglobulin production, thereby potentially regulating allergic phenomena. In a previous study, we showed that the cytokine-releasing activity of extracellular TCTP is generated only when TCTP dimerizes via the intermolecular disulfide bond of NH(2)-terminal truncated TCTP implying that the dimerized TCTP (dTCTP) promotes the inflammatory phenomena. Modulation of dTCTP, thus, may offer a strategy for the treatment of chronic allergic diseases. In this study, we searched for dTCTP-binding peptides (dTBPs) by screening a phage-displayed 7-mer peptide library. We identified one peptide in the library, designated as dTBP2, which showed higher affinity to dTCTP than to full-length, monomeric TCTP. dTBP2 inhibited the induction of IL-8 by dTCTP from BEAS-2B cells. dTBP2 also reduced symptom score and eosinophil infiltration in a mouse rhinitis model. This study suggests that the dTBP2 binding to dTCTP modulates the release of inflammatory mediators of dTCTP. This result may provide a rational strategy for the treatment of allergic diseases.

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.

Efficacy and safety of subcutaneous omalizumab vs placebo as add-on therapy to corticosteroids for children and adults with asthma: a systematic review

BACKGROUND

Omalizumab is a humanized monoclonal anti-IgE for the treatment of severe allergic asthma. Because omalizumab targets an immune system molecule, there has been particular interest in the drug's safety.

METHODS

To establish the efficacy and safety of subcutaneous omalizumab as add-on therapy to corticosteroids, a systematic review of placebo-controlled studies was performed. Primary outcomes were reduction of steroid use and asthma exacerbations. Secondary outcome measures included lung function, rescue medication use, asthma symptoms, health-related quality of life, and adverse effects.

RESULTS

Eight trials (3,429 participants) fulfilled the selection criteria. At the end of the steroid-reduction phase, patients taking omalizumab were more likely to be able to withdraw from corticosteroids completely compared with those taking placebo (relative risk [RR] = 1.80; 95% CI, 1.42-2.28; P = .00001). Omalizumab patients showed a decreased risk of asthma exacerbations at the end of the stable (RR = 0.57; 95% CI, 0.48-0.66; P = .0001) and adjustable-steroid phases (RR = 0.55; 95% CI, 0.47-0.64; P = .0001); post-hoc analysis suggests this effect was independent of duration of treatment, age, severity of asthma, and risk of bias. The frequency of serious adverse effects was similar in the omalizumab (3.8%) and placebo (5.3%) groups. However, injection site reactions were more frequent in the omalizumab patients (19.9% vs 13.2%). There were no indications of increased risk of hypersensitivity reactions, cardiovascular effects, or malignant neoplasms.

CONCLUSIONS

Data indicate that the efficacy of add-on omalizumab in patients with moderate-to-severe allergic asthma is accompanied by an acceptable safety profile.

Recommendation for optimal management of severe refractory asthma

Patients whose asthma is not adequately controlled despite treatment with a combination of high dose inhaled corticosteroids and long-acting bronchodilators pose a major clinical challenge and an important health care problem. Patients with severe refractory disease often require regular oral corticosteroid use with an increased risk of steroid-related adverse events. Alternatively, immunomodulatory and biologic therapies may be considered, but they show wide variation in efficacy across studies thus limiting their generalizability. Managing asthma that is refractory to standard treatment requires a systematic approach to evaluate adherence, ensure a correct diagnosis, and identify coexisting disorders and trigger factors. In future, phenotyping of patients with severe refractory asthma will also become an important element of this systematic approach, because it could be of help in guiding and tailoring treatments. Here, we propose a pragmatic management approach in diagnosing and treating this challenging subset of asthmatic patients.

One year treatment with omalizumab is effective and well tolerated in Japanese Patients with moderate-to-severe persistent asthma

BACKGROUND

We have previously demonstrated that addition of omalizumab to standard therapy improved asthma control by significantly improving lung function and reducing asthma exacerbations in Japanese patients with moderate-to-severe asthma. The aim of this study was to evaluate the effects of omalizumab on long-term disease control in Japanese patients with moderate-to-severe persistent asthma.

METHODS

An open-label, 48-week study was conducted in 133 Japanese patients with moderate-to-severe persistent asthma. Omalizumab was administered subcutaneously every 2 or 4 weeks based on serum IgE level and body weight in each patient.

RESULTS

Treatment with omalizumab significantly improved lung function. A subgroup of patients with inadequately controlled severe persistent asthma, despite high dose inhaled corticosteroids and other multiple controller therapies, which corresponds to the Japanese label (label population), showed greater improvements in morning PEF and FEV(1) than the whole study population (full Analysis Set). Serum free IgE levels decreased to below the target and were maintained during the treatment period in almost all patients. The majority of adverse events were mild-to-moderate in severity and there was no trend toward an increase in incidence of adverse events with increase in duration of omalizumab. In addition, the profile of adverse events in this study was similar to that in a 16-week, placebo-controlled study which the present authors had conducted previously in Japan. There were no anaphylactic reactions and no anti-omalizumab antibodies were detected.

CONCLUSIONS

Long-term treatment with omalizumab is effective and well tolerated in Japanese patients with moderate-to-severe persistent asthma.

Omalizumab in the management of patients with allergic (IgE-mediated) asthma

Immunoglobulin E (IgE) is central to the pathophysiology of allergic asthma. Omalizumab, an anti-IgE monoclonal antibody, binds to the FcɛRI binding site on free IgE. As a result, circulating free IgE is reduced, IgE is prevented from attaching to mast cells and basophils, and FcɛRI receptor expression is down-regulated. The inflammatory response to allergens and the acute and chronic effector phases of allergic inflammation are thereby attenuated. In clinical trials in adults and adolescents, omalizumab reduced asthma exacerbations, severe asthma exacerbations, inhaled corticosteroid requirements, and emergency visits, as well as significantly improving asthma-related quality of life, morning peak expiratory flow and asthma symptom scores in patients with severe allergic (IgE-mediated) asthma. Results from clinical trials in children (<12 years) are consistent with those in the adult population. It is difficult to predict which patients will respond to omalizumab. Responders to omalizumab should be identified after a 16-week trial of therapy using the physician's overall assessment. When treatment is targeted to these responders, omalizumab provides a cost-effective therapy for inadequately controlled severe allergic (IgE-mediated) asthma. Long-term therapy with omalizumab shows the potential for disease-modification in asthma. Ongoing studies are also evaluating the use of omalizumab in other non-asthma IgE-mediated conditions.

Immunomodulatory and biologic therapies for severe refractory asthma

Despite undoubted efficacy of the combination of inhaled corticosteroids and beta(2)-agonists for most asthmatic patients with moderate-to-severe disease, there remains approximately 10% of the asthmatic population with serious unremitting symptoms, resulting in considerable impact on quality of life, disproportionate use of health care resources, and adverse effects from regular systemic steroid use. In an ideal world, optimal treatment of severe refractory asthma should achieve the best possible asthma control and quality of life with the least dose of systemic corticosteroids. The choice and formulation of therapeutic agent are dictated by the severity of disease and may include immunological modifiers and biologic therapies. Unfortunately, current asthma guidelines offer little contribution to the management of the challenging patient with severe refractory asthma and none of them have addressed therapeutic alternatives to oral corticosteroids. This article reviews the current evidence for immunomodulating and biologic approaches in severe refractory asthma.

Severe asthma and the omalizumab option

Atopic diseases and asthma are increasing at a remarkable rate on a global scale. It is now well recognized that asthma is a chronic inflammatory disease of the airways. The inflammatory process in many patients is driven by an immunoglobulin E (IgE)-dependent process. Mast cell activation and release of mediators, in response to allergen and IgE, results in a cascade response, culminating in B lymphocyte, T lymphocyte, eosinophil, fibroblast, smooth muscle cell and endothelial activation. This complex cellular interaction, release of cytokines, chemokines and growth factors and inflammatory remodeling of the airways leads to chronic asthma. A subset of patients develops severe airway disease which can be extremely morbid and even fatal. While many treatments are available for asthma, it is still a chronic and incurable disease, characterized by exacerbation, hospitalizations and associated adverse effects of medications. Omalizumab is a new option for chronic asthma that acts by binding to and inhibiting the effects of IgE, thereby interfering with one aspect of the asthma cascade reviewed earlier. This is a humanized monoclonal antibody against IgE that has been shown to have many beneficial effects in asthma. Use of omalizumab may be influenced by the cost of the medication and some reported adverse effects including the rare possibility of anaphylaxis. When used in selected cases and carefully, omalizumab provides a very important tool in disease management. It has been shown to have additional effects in urticaria, angioedema, latex allergy and food allergy, but the data is limited and the indications far from clear. In addition to decreasing exacerbations, it has a steroid sparing role and hence may decrease adverse effects in some patients on high-dose glucocorticoids. Studies have shown improvement in quality of life measures in asthma following the administration of omalizumab, but the effects on pulmonary function are surprisingly small, suggesting a disconnect between pulmonary function, exacerbations and quality of life. Anaphylaxis may occur rarely with this agent and appropriate precautions have been recommended by the Food and Drug Administration (FDA). As currently practiced and as suggested by the new asthma guidelines, this biological agent is indicated in moderate or severe persistent allergic asthma (steps 5 and 6).

Anti-IgE and other antibody targets in asthma

Asthma is a heterogeneous disorder of unknown etiology that manifests as recurrent episodes of coughing, wheezing, and breathlessness. These symptoms are often debilitating and exacerbations usually are unexpected, resulting in work or school absences, limitations in activity, reduced quality of life, and personal and economic hardships. Over the past several decades, a great deal has been learned about asthma pathophysiology, and currently available therapies have revolutionized asthma treatment. However, asthma remains a global public health problem, and the hope is that newer therapies targeting specific biological mediators of asthma, particularly antibody-mediated therapies, offer exciting new modes to the control of this disease. We will review some of these therapies, with the majority of attention devoted to anti-IgE therapy which has been approved for treatment of adult and childhood asthma by the US Food and Drug Administration (FDA) since 2003.

Omalizumab is more effective than suplatast tosilate in the treatment of Japanese cedar pollen-induced seasonal allergic rhinitis

BACKGROUND

Seasonal allergic rhinitis (SAR) induced by Japanese cedar pollens is a major problem in Japan. Omalizumab, a humanized monoclonal anti-IgE antibody, improves symptoms associated with SAR, but a comparative study with an anti-allergy drug has not yet been conducted.

OBJECTIVE

To compare the efficacy and safety of omalizumab with suplatast tosilate, a selective T-helper type 2 (Th2) cytokine inhibitor, in patients with Japanese cedar pollen-induced SAR.

METHODS

A randomized, double-blind, double-dummy study was conducted in 308 Japanese patients with a history of moderate-to-severe SAR who showed a CAP-RAST value (> or =2+) specifically to Japanese cedar pollens. Patients were treated for 12 weeks with omalizumab plus placebo of suplatast tosilate or suplatast tosilate plus placebo of omalizumab.

RESULTS

The mean daily nasal symptom medication scores (sum of the daily nasal symptom severity score and daily nasal rescue medication score) were significantly lower in the omalizumab group than in the suplatast tosilate group during three evaluation periods (P<0.001). The omalizumab group also had significantly lower mean daily nasal severity scores, each of the mean daily nasal and ocular symptom severity scores (sneezing, runny nose, stuffy nose, itchy nose, itchy eyes, watery eyes, and red eyes). Omalizumab reduced rescue medication requirements, and the proportion of days with any rescue medication use in the omalizumab group was significantly lower. Serum-free IgE levels markedly decreased in the omalizumab group and it was associated with clinical efficacy. The adverse reaction profiles were similar between the two groups. The overall incidence of injection site reactions was higher in the omalizumab group than in the suplatast tosilate group, but all these events were of mild degree. No anti-omalizumab antibodies were detected.

CONCLUSION

Omalizumab showed significantly greater improvements than suplatast tosilate in the treatment of SAR induced by Japanese cedar pollens.