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

Effects of 24 weeks of lansoprazole therapy on asthma symptoms, exacerbations, quality of life, and pulmonary function in adult asthmatic patients with acid reflux symptoms

BACKGROUND

Difficult-to-control asthma has been associated with gastroesophageal acid reflux. Acid-suppressive treatment has been inconsistent in improving asthma control.

OBJECTIVE

To determine whether a proton-pump inhibitor improves asthma control in adult asthmatic patients with acid reflux symptoms.

DESIGN

Multicenter, double-blind, randomized, placebo-controlled trial.

SETTING

Twenty-nine private practices and 3 academic practices in the United States.

PATIENTS

Two hundred seven patients receiving usual asthma care including an inhaled corticosteroid (ICS). Patients had acid reflux symptoms and moderate-to-severe persistent asthma.

INTERVENTION

Lansoprazole, 30 mg bid, or placebo, bid, for 24 weeks.

MEASUREMENTS

The primary outcome measure was daily asthma symptoms by diary. Secondary asthma outcomes included rescue albuterol use, daily morning and evening peak expiratory flow, FEV1, FVC, asthma quality of life with standardized activities (AQLQS) questionnaire score, investigator-assessed symptoms, exacerbations, and oral corticosteroid-treated exacerbations.

RESULTS

Daily asthma symptoms, albuterol use, peak expiratory flow, FEV1, FVC, and investigator-assessed asthma symptoms at 24 weeks did not improve significantly with lansoprazole treatment compared to placebo. The AQLQS emotional function domain improved at 24 weeks (p = 0.025) with lansoprazole therapy. Fewer patients receiving lansoprazole (8.1% vs 20.4%, respectively; p = 0.017) had exacerbations and oral corticosteroid-treated (ie, moderate-to-severe) exacerbations (4% vs 13.9%, respectively; p = 0.016) of asthma. A post hoc subgroup analysis revealed that fewer patients receiving one or more long-term asthma-control medications in addition to an ICS experienced exacerbations (6.5% vs 24.6%, respectively; p = 0.016) and moderate-to-severe exacerbations (2.2% vs 17.5%, respectively; p = 0.021) with lansoprazole therapy.

CONCLUSION

In adult patients with moderate-to-severe persistent asthma and symptoms of acid reflux, treatment with 30 mg of lansoprazole bid for 24 weeks did not improve asthma symptoms or pulmonary function, or reduce albuterol use. However, this dose significantly reduced asthma exacerbations and improved asthma quality of life, particularly in those patients receiving more than one asthma-control medication.

Immunological methods for quantifying free and total serum IgE levels in allergy patients receiving omalizumab (Xolair) therapy

Omalizumab (humanized-IgG1 anti-human IgE Fc, Xolair) complexes circulating IgE, blocking IgE binding to high affinity epsilon Fc receptors (FcepsilonR1) on mast cells and basophils. Free (non-Omalizumab bound) IgE levels in serum are a measure of effective Omalizumab dosing. The goal of this study was to quantify free (non-Omalizumab-complexed) and total serum IgE levels in asthma patients on Xolair. The concentration of (non-Omalizumab bound) free IgE in human serum was measured using a solid phase immunoenzymetric assay (IEMA) in which IgE was captured from serum with monoclonal anti-human IgE (clone HP6061) and detected with labeled-FcepsilonR1alpha. In a companion total human serum IEMA, IgE was captured from serum with the same anti-human IgE (clone HP6061) and all bound IgE was detected with labeled monoclonal anti-human IgE Fc (clone HP6029). Free and total IgE levels were quantified in pre- and 1 and 3 months post Omalizumab therapy sera from 12 allergic asthma patients. In the absence of Omalizumab, working ranges of the free and total IgE IEMAs were comparable (10-1000 kIU/l), with excellent precision, reproducibility and parallelism. Pre-Omalizumab total and free IgE levels by IEMA were highly correlated (r2=0.99, Y=0.9X+0.32, p<0.001), as were total serum IgE levels by IEMA and ImmunoCAP-250 (r2=0.98, Y=1.1X-0.05, p<0.001, n=33). In vitro reduction of free IgE (>90%) occurred at [Omalizumab:IgE] molar ratios of 2-20. Total IgE levels in 12 asthmatics increased from pre-therapy levels (52-658 kIU/l) by 1.5-5.5-fold at 1 month and 1.7-8.6 fold at 3 months of uninterrupted Omalizumab treatment. Free IgE levels fell by 49%-97% at 1 month and 45%-98% by 3 months of Omalizumab treatment. Free and total IgE levels by IEMA aid in monitoring patients receiving Omalizumab therapy.

Cytokine and anti-cytokine therapy for the treatment of asthma and allergic disease

Until recently, the only controller treatment for chronic asthma has been corticosteroids. However, identification of specific effector molecules in asthma has led to targeting of specific pathways by using cytokines and cytokine inhibitors. Administration of a monoclonal blocking antibody against IgE has been shown to be highly efficacious in severe allergic asthma, but blockade of eosinophils using anti-IL-5 monoclonal antibodies has no clinical benefit. In more severe asthma, blockade of TNF-alpha using the decoy etanercept has revealed efficacy in a small open study suggesting that Th-1 in addition to Th-2 pathways are important as the disease adopts a more severe phenotype. It is likely that asthma is not a single disease but a group of disorders which differ in the relative contribution of specific pathophysiological pathways.

Asthma treatment in the 21st century: what's next?

Asthma treatment is evolving as we enter the 21st century. This review focuses on several different areas of asthma treatment now in evolution. These include: (1) the proper role of various asthma controllers--either already approved or under investigation--besides inhaled corticosteriods in asthma therapy; (2) the potential role for immune and cytokine modulation for asthma therapy; (3) the potential role for pharmacogenetics in asthma therapy; and (4) whether single-inhaler therapy with a combination of an inhaled corticosteriod and a long-acted beta-agonist could be used for both maintenance and rescue in patients with asthma.

Immunomodulation in asthma: a distant dream or a close reality?

The search for new treatments of asthma or any other disease for that matter is an infinite exercise. The scope for discovering new forms of treatment has increased now more than ever due to a better understanding of the molecular pathogenesis of the disease. Regulation of biomolecular or immunological events could occur at numerous points in the disease pathogenesis. This review describes the strategies to regulate the inappropriate immune responses that are elicited after exposure to an allergen. One such successful therapy is treatment with omalizumab, the anti-IgE antibody. Other therapies include cytokine antagonists, transcription factor antagonists, immunostimulatory DNA therapy, cytokine therapy and anti-T cell strategies. All these agents have been shown to be promising and could serve as an alternative approach to the treatment of asthma and maybe other allergic diseases.

Allergens in the pathogenesis of asthma: potential role of anti-immunoglobulin E therapy

Evidence suggests that allergy is a significant triggering factor in asthma in children and adults alike. In immunoglobulin (Ig) E-mediated allergic reactions, sensitization occurs when allergen-specific B cells are stimulated and switched to IgE antibody production by interleukin (IL)-4 and IL-13 provided by helper T cells type 2 (Th2). The IgE antibodies act by arming cells bearing either the high-affinity (FcepsilonRI) or low-affinity (FcepsilonRII or CD23) receptor. The subsequent interaction of allergen with IgE-FcepsilonRI complexes on mast cells and basophils causes cross-linking of receptors that triggers the release of a variety of inflammatory mediators, cytokines and chemokines. Therefore, the ability to lower circulating free IgE levels is desirable because most individuals are exposed to multiple allergens to which they are sensitive at any given time. Omalizumab (formerly known as rhuMAb-E25) is a recently developed humanized monoclonal anti-IgE antibody directed at the FcepsilonRI binding domain of human IgE. It inhibits binding of IgE to mast cells without provoking mast cell activation. Preliminary clinical data from randomized controlled trials have shown that the addition of omalizumab to standard asthma therapy reduces asthma exacerbations and decreases inhaled corticosteroid and rescue medication use. The compound is also well tolerated. Omalizumab represents a novel therapeutic approach in the management of asthma.

Targeting immunoglobulin E as a novel treatment for asthma

Omalizumab is a recently developed monoclonal anti-IgE antibody. Clinical trials have demonstrated its efficacy in patients with moderate-to-severe and severe or poorly controlled allergic asthma, in patients with seasonal and perennial allergic disease, and in subjects with concomitant asthma and allergic rhinitis. Patients with more severe asthma appear to obtain the greatest benefit from omalizumab therapy. Omalizumab is well tolerated and has a good safety profile. Anti-inflammatory activity has been shown in both allergic asthma and allergic rhinitis. These results confirm the importance of IgE in allergic disease and support the rationale behind the development of a therapeutic anti-IgE antibody. Omalizumab is a significant addition to current asthma treatments and shows great promise as a therapy for allergic rhinitis, in particular for those patients with concomitant allergic disease.

Anti-IgE antibodies for the treatment of asthma

PURPOSE OF REVIEW

Allergic asthma is a hypersensitivity reaction initiated by immunologic mechanisms mediated by IgE antibodies. IgE plays a central role in the initiation and propagation of the inflammatory cascade and thus the allergic response. Targeting factors involved in the allergic response, such as IgE, is a novel strategy for new therapies. Attenuating allergic disease by specifically inhibiting IgE and the development of the monoclonal anti-IgE antibody, omalizumab, were major breakthroughs in asthma management.

RECENT FINDINGS

Several studies have shown that omalizumab has significant anti-inflammatory effects and that it may act on multiple components of the inflammatory cascade. Specific binding of IgE by omalizumab reduces both the early allergic response and the late allergic response and symptoms of IgE-mediated allergy. The long-term clinical efficacy of omalizumab has been demonstrated along with improvements in quality of life. As add-on therapy in severe asthma, omalizumab reduces the requirement for inhaled corticosteroids and improves disease control. Clinical studies have shown that the patients who benefit most from omalizumab therapy are those at high risk of exacerbations, those with poorly controlled and/or severe asthma, and those with IgE-mediated comorbidities.

SUMMARY

Omalizumab is a significant addition to current asthma treatments and shows great promise as a therapy for allergic asthma and for patients with concomitant allergic rhinitis. This is particularly true for difficult-to-treat patients with moderate to severe allergic asthma who have poorly controlled disease on conventional therapies, experience severe adverse effects secondary to high-dose or prolonged corticosteroid treatment, have frequent exacerbations, and/or are at high risk of hospitalization. Future studies will continue to investigate the anti-inflammatory mechanisms of anti-IgE therapy. Because many of these mechanisms are common to all IgE-mediated allergic diseases, the efficacy of omalizumab in other allergic diseases should be further explored.

Anti-immunoglobulin E treatment with omalizumab in allergic diseases: an update on anti-inflammatory activity and clinical efficacy

Omalizumab is a humanized monoclonal anti-IgE antibody developed for the treatment of allergic disease, with established efficacy in patients with moderate-to-severe allergic asthma and in patients with intermittent (seasonal) and persistent (perennial) allergic rhinitis (AR). Omalizumab is known to result in a marked reduction in serum levels of free IgE and down-regulation of IgE receptors on circulating basophils. Recent work has shed further light on its mechanism of action, showing significant and profound reductions in tissue (nasal and bronchial) eosinophils and in bronchial IgE+ cells (mast cells), as well as T cells and B cells. Omalizumab treatment was also shown to be associated with down-regulation of IgE receptors on circulating (precursor) dendritic cells, suggesting that blocking IgE may inhibit more chronic aspects of allergic inflammation involving T cell activation. Further work with omalizumab demonstrated it to have important benefits in patients with poorly controlled asthma despite high-dose inhaled corticosteroid therapy, and analysis of clinical data suggests that the patients who are the best 'responders' to anti-IgE treatment are those with asthma at the more severe end of the spectrum. Notably, systemic anti-IgE therapy with omalizumab has been shown to improve symptoms, quality of life and disease control (asthma exacerbations) in patients with concomitant asthma and persistent AR. These impressive clinical data and the studies elucidating the anti-inflammatory profile of omalizumab also serve to emphasize the fundamental importance of IgE in the pathogenesis of allergic diseases.

Asthma and therapeutics: recombinant therapies in asthma

Numerous recombinant therapies are being investigated for the treatment of asthma. This report reviews the current status of several of these novel agents. Anti-immunoglobulin (Ig)E (omalizumab, Xolair) markedly inhibits all aspects of the allergen challenge in subjects who have reduction of free serum IgE to undetectable levels. Several clinical studies in atopic asthma have demonstrated benefit by improved symptoms and lung function and a reduction in corticosteroid requirements. Early use in atopic asthmatics may be even more effective. Several approaches target interleukin (IL)-4. Soluble IL-4 receptor has been shown to effectively replace inhaled corticosteroid; further studies are under way. Recombinant anti-IL-5 and recombinant IL-12 inhibit blood and sputum eosinophils and allergen-induced eosinophilia without any effect on airway responsiveness, allergen-induced airway responses, or allergen-induced airway hyperresponsiveness. Efalizumab, a recombinant antibody that inhibits lymphocyte trafficking, is effective in psoriasis. A bronchoprovocation study showed a reduction in allergen-induced late asthmatic response and allergen-induced eosinophilia, which suggests that it should be effective in clinical asthma. These exciting novel therapies provide not only promise of new therapies for asthma but also valuable tools for investigation of asthma mechanisms.

Severe asthma treatment: need for characterising patients

CONTEXT

Asthma is readily diagnosed in most cases and usually responds to inhaled corticosteroids with or without long-acting beta agonists, theophyllines, or leukotriene-receptor antagonists, adjusted stepwise according to symptoms and lung function. However, up to 40% of adult patients with asthma remain symptomatic, and up to 5% have difficult-to-control asthma despite multiple therapies. It is suggested that higher doses of inhaled steroids with long-acting beta2 agonists should be used for total control of symptoms; and anti-IgE therapy is newly licensed in the USA. However, difficult-to-control asthma is complex and multifactorial, and is often not due to severe or therapy-resistant asthma.

STARTING POINT

Last year saw encouraging reports on omalizumab (anti-IgE therapy) in severe allergic asthma, by Stephen Holgate, Jon Ayres, and their respective colleagues (Clin Exp Allergy 2004; 34: 632-38; Allergy 2004; 59: 701-08). Omalizumab reduced exacerbation rates, improved asthma symptoms and quality of life, and allowed lower doses of inhaled steroid compared with placebo. In placebo-controlled studies with anti-IgE, many patients were able to substantially reduce and even withdraw inhaled steroids in the placebo arm.

WHERE NEXT

Severe asthma is often defined as persisting symptoms despite high-dose inhaled steroids. This definition is likely to include patients with various reasons for their persisting symptoms, for whom additional treatment is not always required. Before starting new therapy, it is important to systematically evaluate asthmatic patients to accurately define their disease and to identify those whose symptoms are caused by other factors, and thus avoid unnecessary medication. There might also be subgroups that have differing underlying inflammatory processes and who will respond differently to individual treatments.

New strategies in the treatment and prevention of allergic diseases

Allergic diseases (AD) are more prevalent today than 30 years ago but over the same period, few novel efficacious drugs have been discovered to treat, control or even cure these disorders. Topical or systemic glucocorticosteroids combined with symptom-relieving medications, such as beta 2 -adrenoceptor agonists, leukotriene inhibitors or antihistamines, are still the mainstay of antiallergic treatment. Modified glucocorticosteroids with less adverse effects, better bronchodilators and new selective mediator inhibitors may improve symptom control in the future. Only specific immunotherapy has shown potential for long-lasting disease-modifying effects. Immunomodulation is a therapeutic goal, aiming to modify the dominant helper T cell Type 2 inflammation to a helper T cell Type 1 response using modified allergens, mycobacteria or CpG oligodeoxynucleotides. Humanised monoclonal anti-IgE antibodies are an exciting new immunomodulatory medication that are expected to reach the clinical practice and have recently been licensed in Australia and the US. Advances in molecular, cellular and genetic research of the immunopathophysiology of AD have led to the development of new antagonists for cytokines, chemokines, receptors, second messengers and transcription factors that may become available for clinical use in the next 10 years. Specific diets supplemented with antioxidants or probiotics need further study but offer promise as safe and cheap preventative medicine. The strong genetic component of AD and the Human Genome Project have opened a new field of research, and modification or replacement of target genes has a curative potential with exciting new therapeutic developments in the years ahead.

Benefits of omalizumab as add-on therapy in patients with severe persistent asthma who are inadequately controlled despite best available therapy (GINA 2002 step 4 treatment): INNOVATE

BACKGROUND

Patients with severe persistent asthma who are inadequately controlled despite Global Initiative for Asthma (GINA) 2002 step 4 therapy are a challenging population with significant unmet medical need. We determined the effect of omalizumab on clinically significant asthma exacerbations (requiring systemic corticosteroids) in the first omalizumab study to exclusively enrol patients from this difficult-to-treat patient population.

METHODS

Following a run-in phase, patients (12-75 years) inadequately controlled despite therapy with high-dose inhaled corticosteroids (ICS) and long-acting beta(2)-agonists (LABA) with reduced lung function and a recent history of clinically significant exacerbations were randomized to receive omalizumab or placebo for 28 weeks in a double-blind, parallel-group, multicentre study.

RESULTS

A total of 419 patients were included in the efficacy analyses. The clinically significant asthma exacerbation rate (primary efficacy variable), adjusted for an observed relevant imbalance in history of clinically significant asthma exacerbations, was 0.68 with omalizumab and 0.91 with placebo (26% reduction) during the 28-week treatment phase (P = 0.042). Without adjustment, a similar magnitude of effect was seen (19% reduction), but this did not reach statistical significance. Omalizumab significantly reduced severe asthma exacerbation rate (0.24 vs 0.48, P = 0.002) and emergency visit rate (0.24 vs 0.43, P = 0.038). Omalizumab significantly improved asthma-related quality of life, morning peak expiratory flow and asthma symptom scores. The incidence of adverse events was similar between treatment groups.

CONCLUSIONS

In patients with inadequately controlled severe persistent asthma, despite high-dose ICS and LABA therapy, and often additional therapy, omalizumab significantly reduced the rate of clinically significant asthma exacerbations, severe exacerbations and emergency visits. Omalizumab is effective and should be considered as add-on therapy for patients with inadequately controlled severe persistent asthma who have a significant unmet need despite best available therapy.

The effect of treatment with omalizumab, an anti-IgE antibody, on asthma exacerbations and emergency medical visits in patients with severe persistent asthma

BACKGROUND

Patients with severe persistent asthma who are inadequately controlled despite treatment according to current asthma management guidelines have a significant unmet medical need. Such patients are at high risk of serious exacerbations and asthma-related mortality.

METHODS

Here, we pooled data from seven studies to determine the effect of omalizumab, an anti-immunoglobulin E (IgE) monoclonal antibody, on asthma exacerbations in patients with severe persistent asthma. Omalizumab was added to current asthma therapy and compared with placebo (in five double-blind studies) or with current asthma therapy alone (in two open-label studies). The studies included 4308 patients (2511 treated with omalizumab), 93% of whom had severe persistent asthma according to the Global Initiative for Asthma (GINA) 2002 classification. Using the Poisson regression model, results were calculated as the ratio of treatment effect (omalizumab : control) on the standardized exacerbation rate per year.

RESULTS

Omalizumab significantly reduced the rate of asthma exacerbations by 38% (P < 0.0001 vs control) and the rate of total emergency visits by 47% (P < 0.0001 vs control). Analysis of demographic subgroups showed that the efficacy of omalizumab on asthma exacerbations was unaffected by patient age, gender, baseline serum IgE (split by median) or by 2- or 4-weekly dosing schedule, although benefit in absolute terms appeared to be greatest in patients with more severe asthma, defined by a lower value of percentage predicted forced expiratory volume in 1 s (FEV(1)) at baseline.

CONCLUSIONS

These results suggest that omalizumab may fulfil an important need in patients with severe persistent asthma, many of whom are not adequately controlled on current therapy.

An immunoepidemiological approach to asthma: identification of in-vitro T-cell response patterns associated with different wheezing phenotypes in children

BACKGROUND

Increasing evidence suggests that patterns of T-cell immunity to inhalant allergens in genetically diverse human populations are more heterogeneous than previously assumed, and that covert differences in expression patterns might underlie variations in airway disease phenotypes. We tested this proposition in a community sample of children.

METHODS

We analysed data from 172 individuals who had been recruited antenatally to a longitudinal birth cohort study. Of the 194 birth cohort participants, data from the 147 probands (age range 8.6-13.5 years) who consented to blood collection were included along with data from 25 consenting siblings (mean age 11 years [range 7.4-17.4]). We ascertained clinical phenotypes related to asthma and allergy. We measured T-cell responses to allergens and mitogens, together with blood eosinophils and IgE/IgG antibodies, and assessed associations between these indices and clinical phenotypes.

FINDINGS

Atopy was associated with allergen-specific T-helper (Th)2 responses dominated by interleukin 4, interleukin 5, interleukin 9, interleukin 13, whereas interleukin 10, tumour necrosis factor alpha, and interferon gamma responses were common to both atopics and non-atopics. The wheal size from skin prick with allergen was positively associated with in-vitro interleukin 5 and interferon gamma responses, and negatively associated with interleukin 10. Asthma, especially in atopics, was strongly associated with eosinophilia/interleukin 5, and bronchial hyper-responsiveness (BHR) was associated with eosinophilia plus polyclonal interferon gamma production. BHR in non-atopics was associated with elevated allergen-specific and polyclonal interleukin 10 production.

INTERPRETATION

Parallel immunological and clinical profiling of children identified distinctive immune response patterns related to asthma and wheeze compared with BHR, in atopics non-atopics. Immunological hyper-responsiveness, including within the Th1 cytokine compartment, is identified as a hallmark of BHR.

RELEVANCE TO PRACTICE

These findings highlight the heterogeneity of immune response patterns in asthmatic children, including those with seemingly homogeneous Th2-driven atopic asthma. Further elucidation of the covert relationships between wheezing phenotypes and underlying immunophenotypes in this age group will potentially lead to more effective treatments for what is an unexpectedly heterogeneous collection of disease subtypes.

Anti-IgE therapy

IgE has a central role in the initiation of allergic hypersensitivity reactions. Pioneered by the development of humanized monoclonal antibodies directed against IgE, anti-IgE therapy represents an original approach to the treatment of allergic disease and has demonstrated promise in preventing the symptoms of asthma, allergic rhinitis, and food allergy. The primary mechanism of action of anti-IgE therapy is the reduction in serum levels of IgE and FcepsilonRI expression on mast cells and basophils.

New advances and potential therapies for the treatment of asthma

Asthma is a disease of the airways with an underlying inflammatory component. The prevalence and healthcare burden of asthma is still rising and is predicted to continue to rise in the current century. Inhaled beta(2)-adrenoceptor agonists and corticosteroids form the basis of the treatments available to alleviate the symptoms of asthma. There is a need for novel, safe treatments to tackle the underlying inflammation that characterizes asthma pathology. Furthermore, there is a requirement for new treatments to be developed as oral therapy in order to alleviate patient compliance issues, especially in children. A multitude of new approaches and new targets are being investigated, which may provide opportunities for novel therapeutic interventions in this debilitating disease. For simplicity, these approaches can be divided into two categories. The first comprises therapies directed against specific components or steps seen in allergic asthma. By 'components' we mean the key inflammatory cells (T cells [in particular T(h)2], B cells, eosinophils, mast cells, basophils and antigen presenting cells [APC]) and mediators (immunoglobulin E [IgE], cytokines, histamines, leukotrienes and prostanoids) believed to be involved in the chronic inflammation seen in asthma. By 'steps' we mean the allergic response, such as antigen processing and presentation, T(h)2-cell activation, B-cell isotype switching, mast cell involvement and airway remodeling. The other category of novel approaches to disease modification in asthma encompasses general anti-inflammatory therapies including phosphodiesterase 4 (PDE4) inhibitors, p38 mitogen-activated protein kinase (MAPK) inhibitors, peroxisome proliferator-activated receptor-gamma (PPARgamma) agonists, and lipoxins.

Anti-IgE therapy in allergic disease

PURPOSE OF REVIEW

Recombinant monoclonal humanized anti-IgE has put forward a fundamentally new concept for the control of allergic disorders. This review will present recent data from clinical studies with anti-IgE in asthma, allergic rhinitis, and food allergy and will examine the place of anti-IgE among current therapeutic options for the treatment of asthma.

RECENT FINDINGS

Therapy with anti-IgE depresses circulating free IgE to the limits of detection, inhibits early- and late-phase responses to allergens, suppresses inflammation and improves the control of allergic diseases. In moderate to severe asthma it results in fewer exacerbations and a lower requirement for both corticosteroids and beta-agonists. IgE appears to be an important regulator of high-affinity Fc receptors (FcepsilonRI) and, in the mouse, to enhance mast cell survival and activation. IgE receptors have been found on diverse inflammatory cells. Anti-IgE reduces the expression of FcepsilonRI on inflammatory cells. Current work has documented a marked decrease in tissue eosinophils, lymphocytes, and interleukin-4-positive cells by anti-IgE treatment and has provided insight into the mechanisms underlying improved control of asthma.

SUMMARY

Clinical studies with anti-IgE have promoted and will continue to advance the understanding of IgE-mediated disease mechanisms. They have documented its efficacy in the treatment of allergic diseases, but much remains to be learned about the most effective clinical strategies and the selection of patients for therapy.

Effect of anti-immunoglobulin E on nasal inflammation in patients with seasonal allergic rhinoconjunctivitis

BACKGROUND

Binding of allergens to IgE on mast cells and basophils causes release of inflammatory mediators in nasal secretions.

OBJECTIVE

The combined effect of specific immunotherapy (SIT) and omalizumab, a humanized monoclonal anti-IgE antibody, on release of eosinophilic cationic protein (ECP), tryptase, IL-6, and IL-8 in nasal secretion was evaluated.

METHODS

Two hundred and twenty five children (aged 6-17 years) with a history of seasonal allergic rhinoconjunctivitis induced by birch and grass pollen were randomized into four groups: either birch- or grass-pollen SIT in combination with either anti-IgE or placebo. Complete sets of nasal secretion samples before treatment Visit 1 (V1), during birch- (V2) and grass (V3)-pollen season and after the pollen season (V4) were collected from 53 patients.

RESULTS

A significant reduction in tryptase only was seen in the anti-IgE-treated group at V2 (P<0.05) and V4 (P<0.05) compared with the placebo group. During the pollen season, patients with placebo showed an increase of ECP compared with baseline (V2: +30.3 microg/L; V3: +134.2 microg/L, P< 0.005; V4: +79.0 microg/L, P< 0.05), and stable levels of tryptase, IL-6 and IL-8. Treatment with anti-IgE resulted in stable ECP values and a significant decrease of tryptase compared with V1 (baseline): V2: -80.0 microg/L (P< 0.05); V3: -56.3 microg/L, which persisted after the pollen season with V4: -71.6 microg/L (P< 0.05). After the pollen season, a decrease of IL-6 was observed in both groups (V4 placebo group: -37.5 ng/L; V4 anti-IgE group: -42.9 ng/L, P< 0.01).

CONCLUSION

The combination of SIT and anti-IgE is associated with prevention of nasal ECP increase and decreased tryptase levels in nasal secretions.

Rationale for new treatments aimed at IgE immunomodulation

OBJECTIVE

To review potential or current therapies that decrease IgE synthesis or effects.

DATA SOURCES

Relevant literature in peer-reviewed journals and abstracts from national meetings.

STUDY SELECTION

Key articles were selected by the authors.

RESULTS

Modulation of IgE-mediated diseases can occur at several levels. Transcription factors may be altered to differentiate lymphocytes into a TH1 phenotype, thus decreasing TH2-driven IgE production. This may be accomplished by inhibiting GATA-3 with peroxisome proliferator-activated receptor agonists or promoting T-bet expression with CpG motifs. Inhibiting IgE-promoting cytokines may be accomplished by blocking the effects or synthesis of interleukin 4 (IL-4) or IL-13 by suplatast tosilate. Cytokine therapy with anti-IL-4 or anti-IL-13 has the potential to directly influence IgE-mediated diseases, but strategies aimed at IL-4 alone have been disappointing. Clinical trials with interferon-gamma or IL-12, 2 cytokines important in promoting TH1 and inhibiting TH2 responses, have been fraught with adverse effects that make their use limited. The use of plasmids encoding interferon-gamma or IL-12 has shown promise in animal models. Inhibition of IgE synthesis has been demonstrated with anti-CD23 antibodies. Early human studies have been very encouraging, and larger studies are under way. The only IgE immunomodulator currently available for use is omalizumab. Omalizumab is effective for allergic asthma in children and adults.

CONCLUSIONS

Newer therapies hold great promise for the future treatment of allergic respiratory diseases, but clinical trials are necessary to accurately evaluate risk-benefit ratios of IgE immunomodulators.

T-cell trafficking in asthma: lipid mediators grease the way

Recruitment of T cells to the airways is crucial in the pathogenesis of asthma, and it is thought to be mediated mainly by peptide chemokines. By contrast, lipid mediators such as leukotrienes and prostaglandins have classically been thought to contribute to asthma pathogenesis by other mechanisms. However, as we discuss here, the recent molecular identification of leukotriene and prostaglandin receptors, as well as the generation of mice that are genetically deficient in them, has revealed that two of these lipids - leukotriene B(4) and prostaglandin D(2) - also direct T-cell migration and seem to cooperate with chemokines in a non-redundant, sequential manner to recruit T cells to the airways in asthma.

Current and emerging nonsteroidal anti-inflammatory therapies targeting specific mechanisms in asthma and allergy

Today inhaled corticosteroids (ICS) are regarded as the first-line controller anti-inflammatory treatment in the management of asthma. However, there is an increasing awareness of the risk of long-term adverse effects of ICS and that asthma is not only an organ-specific disease but also a systemic and small airway disease. This thinking has called for systemic treatment alternatives to treat asthma targeting more disease-specific mechanisms without influencing normal physiologic functions. Blocking of disease-specific mediators is a mechanism utilized by anti-leukotrienes and anti-immunoglobulin E treatment, each proven to be effective in both asthma and allergic rhinitis.Different cytokine-modifying strategies have been tested in clinical trials with variable results, some disappointing and some encouraging. Anti-interleukin (IL)-5 monoclonal antibody treatment effectively reduces the number of eosinophils locally in the airways and in peripheral blood in asthmatic patients. Unfortunately, this marked effect on eosinophils was not associated with an improvement in bronchial hyperresponsiveness and/or symptoms. Clinical trials with a recombinant soluble IL-4 receptor have been somewhat more successful at improving asthma control and allowing reduction of ICS therapy in asthma. Treatment with recombinant IL-12 had an effect on bronchial hyperresponsiveness and eosinophilic response, but was associated with unacceptable adverse effects. Other interesting cytokine-modulating treatments include those targeting IL-9, IL-10, IL-12 and IL-13.Immune-modulating treatment with bacterial antigens represents another strategy, originating from the hypothesis that some bacterial infections guide the immune system towards a T helper (Th) type 1 immune response. Mycobacterium vaccae, Bacille Calmette-Guerin (BCG) and immunostimulatory DNA sequences have all been tested in clinical trials, with encouraging results. Future asthma and allergy treatment will probably include not only one but also two or more disease-modifying agents administered to the same patient.

Cost-effectiveness analysis of omalizumab in adults and adolescents with moderate-to-severe allergic asthma

BACKGROUND

Omalizumab can reduce hospitalization and emergency department visits and improve quality of life in patients with moderate-to-severe, suboptimally controlled allergic asthma. Given the high cost and modest efficacy of this agent, it is not clear that it is cost-effective if given to a broad population with asthma.

OBJECTIVE

The purpose of this study was to evaluate the cost-effectiveness of omalizumab in adults and adolescents with moderate-to-severe allergic asthma.

METHODS

A retrospective economic analysis was performed to determine the cost-effectiveness of omalizumab using 52-week data from 2 randomized controlled clinical trials in adults and adolescents with moderate-to-severe allergic asthma. The analysis was conducted from a third-party payer's perspective, and only direct costs were considered.

RESULTS

The incremental cost-effectiveness ratios showed that the cost to achieve an additional successfully controlled day was $523, and the daily cost to achieve at least a 0.5-point increase in Asthma Quality of Life Questionnaire score was $378 in 2003 dollars.

CONCLUSION

From a pharmacoeconomic standpoint, omalizumab would be better used in allergic asthmatic patients with poorly controlled symptoms despite maximal therapy, given the high cost and modest efficacy of this agent. It could be cost saving if given to nonsmoking patients who are hospitalized 5 or more times or 20 days or longer per year despite maximal asthma therapy.

Is there a role for anti-IgE in combination with specific allergen immunotherapy?

PURPOSE OF REVIEW

A line of novel therapeutic approaches that try to interfere more specifically with the immunological mechanisms underlying allergen-induced pathology are currently undergoing clinical evaluation. The most advanced of these is anti-IgE, which directly targets IgE serum antibodies, thus inhibiting the central mechanism of immediate type hypersensitivity reactions. In addition, a lot of interest has recently been focused on allergen-specific immunotherapy due to its potential to cure allergic diseases. In the present review, state-of-the-art treatment of allergic diseases with anti-IgE and allergen-specific immunotherapy is summarized, and the potential of combination therapy with both treatment options is discussed.

RECENT FINDINGS

Application of anti-IgE antibodies effectively reduces IgE serum levels regardless of allergen specificity. This treatment has been successfully tested in patients with allergic rhinitis, asthma and food allergy, showing significant efficacy in reducing symptom scores and rescue medication use. Anti-IgE therapy is limited by high costs and the necessity for permanent or every-season treatment. The strongest argument in favor of allergen-specific immunotherapy is the potential to cure allergic diseases, which has been demonstrated in patients with allergic rhinitis, insect venom allergy and, to a lesser degree, asthma. The broader application of allergen-specific immunotherapy is restricted by sometimes life-threatening side effects. A combination of anti-IgE and allergen-specific immunotherapy was shown to be superior to each single treatment protocol in children and adolescents with allergic rhinitis, as demonstrated by efficacy of symptom scores and rescue medication use.

SUMMARY

There are strong arguments for a combination of anti-IgE plus allergen-specific immunotherapy for treatment of allergic diseases: improved efficacy, limited side effects, and potential curative effects.

Efficacy and safety of a recombinant anti-immunoglobulin E antibody (omalizumab) in severe allergic asthma

BACKGROUND

Patients with severe asthma are often inadequately controlled on existing anti-asthma therapy, constituting an unmet clinical need.

OBJECTIVE

This randomized, double-blind, placebo-controlled trial evaluated the ability of omalizumab, a humanized monoclonal anti-IgE antibody, to improve disease control sufficiently to enable inhaled corticosteroid reduction in patients with severe allergic asthma.

METHODS

After a run-in period when an optimized fluticasone dose (> or =1000 microg/day) was received for 4 weeks, patients were randomized to receive subcutaneous omalizumab [minimum 0.016 mg/kg/IgE (IU/mL) per 4 weeks; n=126] or matching placebo (n=120) at intervals of 2 or 4 weeks. The study comprised a 16-week add-on phase of treatment followed by a 16-week fluticasone-reduction phase. Short-/long-acting beta(2)-agonists were allowed as needed.

RESULTS

Median reductions in fluticasone dose were significantly greater with omalizumab than placebo: 60% vs. 50% (P=0.003). Some 73.8% and 50.8% of patients, respectively, achieved a > or =50% dose reduction (P=0.001). Fluticasone dose reduction to < or =500 microg/day occurred in 60.3% of omalizumab recipients vs. 45.8% of placebo-treated patients (P=0.026). Through both phases, omalizumab reduced rescue medication requirements, improved asthma symptoms and asthma-related quality of life compared to placebo.

CONCLUSION

Omalizumab treatment improves asthma control in severely allergic asthmatics, reducing inhaled corticosteroid requirements without worsening of symptom control or increase in rescue medication use.

Omalizumab and the treatment of allergic rhinitis

Anti-IgE therapy affects mechanisms in the allergic response that are IgE-dependent or IgE-mediated and common to both allergic asthma and allergic rhinitis. Clinical trials of omalizumab in the treatment of patients with allergic rhinitis or comorbid allergic rhinitis and moderate to severe allergic asthma have recorded significant reductions in symptom severity scores of both conditions. This novel therapy has increased the knowledge base concerning IgE-mediated allergic responses, and, in keeping with its actions established in the treatment of asthma, appears to be useful in the treatment of moderate to severe allergic rhinitis, as well.

Efficacy and tolerability of anti-immunoglobulin E therapy with omalizumab in patients with concomitant allergic asthma and persistent allergic rhinitis: SOLAR

BACKGROUND

Anti-IgE therapy could be particularly beneficial for patients with concomitant disease as it targets a common factor in both diseases. The aim of this study was to evaluate the efficacy and safety of omalizumab in patients with concomitant moderate-to-severe asthma and persistent allergic rhinitis.

METHODS

This multicentre, randomized, double-blind, parallel-group, placebo-controlled trial evaluated the safety and efficacy of omalizumab. A total of 405 patients (12-74 years) with a stable treatment (>/= 400 microg budesonide Turbuhaler) and >/= 2 unscheduled medical visits for asthma during the past year or >/= 3 during the past 2 years were enrolled. Patients received omalizumab (>/= 0.016 mg/kg/IgE [IU/ml] per 4 weeks) or placebo for 28 weeks.

RESULTS

Fewer patients treated with omalizumab experienced asthma exacerbations (20.6%) than placebo-treated patients (30.1%), P = 0.02. A clinically significant (>/= 1.0 point) improvement in both Asthma Quality of Life Questionnaire and Rhinitis Quality of Life Questionnaire occurred in 57.7% of omalizumab patients compared with 40.6% of placebo patients (P < 0.001). Omalizumab reduced Wasserfallen symptom scores for asthma (P = 0.023), rhinitis (P < 0.001) and the composite asthma/rhinitis scores (P < 0.001) compared with placebo. Serious adverse events were observed in 1.4% of omalizumab-treated patients and 1.5% of placebo-treated patients.

CONCLUSION

Omalizumab is well tolerated and effective in preventing asthma exacerbations and improving quality of life in patients with concomitant asthma and persistent allergic rhinitis.

Efficacy and tolerability of anti-immunoglobulin E therapy with omalizumab in patients with poorly controlled (moderate-to-severe) allergic asthma

BACKGROUND

Patients with poorly controlled asthma have greater morbidity and mortality. This study evaluated the efficacy and tolerability of omalizumab in patients with poorly controlled, moderate-to-severe allergic asthma.

METHODS

This was a randomized, open-label, multicentre, parallel-group study. A total of 312 patients (12-73 years) receiving >/=400 microg/day (adolescent) or >/=800 microg/day (adult) inhaled beclomethasone dipropionate, or equivalent were included. Patients received best standard care (BSC) with or without omalizumab [at least 0.016 mg/kg/IgE (IU/ml) every 4 weeks] for 12 months.

RESULTS

The annualized mean number of asthma deterioration-related incidents was reduced from 9.76 with BSC alone (n = 106) to 4.92 per patient-year with omalizumab (n = 206) (P < 0.001). Mean clinically significant asthma exacerbation rates were 2.86 and 1.12 per patient-year, respectively (P < 0.001). Omalizumab-treated patients (41.4%) required rescue medication <1 day/week compared with 20.7% for BSC alone (P < 0.001). Omalizumab improved absolute forced expiratory volume in 1 s (FEV(1)) compared with BSC alone (2.48 and 2.28 l, respectively; P < 0.05) and reduced symptom scores relative to BSC alone (decrease of 6.5 and 0.7 respectively; P < 0.001). Omalizumab was well-tolerated.

CONCLUSIONS

Omalizumab administered as add-on therapy to BSC benefits patients with poorly controlled, moderate-to-severe allergic asthma.

Anti-IgE monoclonal antibody, omalizumab: a new treatment for allergic asthma

Omalizumab (Xolair Genentech, USA/Tanox, Inc., USA/Novartis Pharma AG, Switzerland) - a humanised antibody to IgE that reduces circulating free IgE - has been developed for the treatment of allergic asthma. It inhibits the early- and late-phase response to allergens, suppresses eosinophilic and T cell inflammation in asthmatic airways and reduces the levels of high-affinity IgE receptors on basophils. In clinical trials of moderate-to-severe asthma, omalizumab allowed a reduction in inhaled corticosteroid dosage while improving peak flows and reducing exacerbations, particularly in patients at high-risk of serious asthma-related morbidity and improved quality of life scores. When added to existing therapies of patients with more severe asthma, omalizumab also improved asthma control. Additionally, in asthma patients with concomitant perennial allergic rhinitis, omalizumab provides improvement in these comorbid conditions. Omalizumab is well-tolerated by asthma patients and represents a new approach to the treatment of the moderate-to-severe asthmatic patient. It is likely that it will first be used at the more severe end of the asthmatic diathesis.

Omalizumab: a novel therapy for allergic asthma

OBJECTIVE

To review the pharmacology, efficacy, and safety of omalizumab, focusing on the treatment of allergic asthma.

DATA SOURCES

A MEDLINE search (1966-November 2003) was conducted using the key words omalizumab, Xolair, and Rhu-MAB25, with studies limited to those in humans and published in English. References of identified articles were reviewed for additional citations.

STUDY SELECTION AND DATA EXTRACTION

Clinical trials evaluating the pharmacology, efficacy, and safety of omalizumab for treatment of allergic asthma in patients aged >or=12 years were selected. Clinical trials examining utility in pediatric patients were also reviewed.

DATA SYNTHESIS

Omalizumab's ability to form complexes with unbound immunoglobulin E (IgE) translates into decreased unbound serum IgE levels and high-affinity IgE receptors on basophils, as well as attenuation of early and late allergic response in patients with allergic asthma. Results of clinical trials demonstrated that omalizumab administered subcutaneously is a safe and effective treatment for moderate to severe allergic asthma. Generally, omalizumab has a mild adverse effect profile. Omalizumab may be particularly useful for treatment of moderate to severe allergic asthma in patients who are poorly controlled on conventional therapy, experience adverse effects secondary to high-dose or prolonged corticosteroid treatment, or who have frequent exacerbations because of poor medication adherence. The high cost associated with omalizumab treatment may be prohibitive for some patients, thereby limiting its utility.

CONCLUSIONS

Omalizumab is a safe and effective therapy for treatment of moderate to severe allergic asthma in difficult-to-treat, high-risk patients.

Effects of treatment with anti-immunoglobulin E antibody omalizumab on airway inflammation in allergic asthma

IgE plays an important role in allergic asthma. We hypothesized that reducing IgE in the airway mucosa would reduce airway inflammation. Forty-five patients with mild to moderate persistent asthma with sputum eosinophilia of 2% or more were treated with humanized monoclonal antibody against IgE (omalizumab) (n = 22) or placebo (n = 23) for 16 weeks. Outcomes included inflammatory cells in induced sputum and bronchial biopsies, and methacholine responsiveness. Treatment with omalizumab resulted in marked reduction of serum IgE and a reduction of IgE+ cells in the airway mucosa. The mean percentage sputum eosinophil count decreased significantly (p < 0.001) from 6.6 to 1.7% in the omalizumab group, a reduction significantly (p = 0.05) greater than with placebo (8.5 to 7.0%). This was associated with a significant reduction in tissue eosinophils; cells positive for the high-affinity Fc receptor for IgE; CD3+, CD4+, and CD8+ T lymphocytes; B lymphocytes; and cells staining for interleukin-4, but not with improvement in airway hyperresponsiveness to methacholine. This study shows antiinflammatory effects of omalizumab treatment and provides clues for mechanisms whereby omalizumab reduces asthma exacerbations and other asthma outcomes in more severe asthma. The lack of effect of omalizumab on methacholine responsiveness suggests that IgE or eosinophils may not be causally linked to airway hyperresponsiveness to methacholine in mild to moderate asthma.

Predicting response to omalizumab, an anti-IgE antibody, in patients with allergic asthma

STUDY OBJECTIVE

To determine baseline characteristics predictive of response to omalizumab, an anti-IgE antibody, in patients with allergic asthma.

DESIGN

Pooled analysis of two multicenter, double-blind, randomized, placebo-controlled phase III studies with omalizumab.

PATIENTS

One thousand seventy allergic asthma patients symptomatic despite moderate-to-high doses (mean, 725 micro g/d) of inhaled beclomethasone dipropionate (BDP).

INTERVENTIONS

Omalizumab (n = 542) or placebo (n = 528) were administered at a 4-weekly subcutaneous dose of at least 0.016 mg/kg/IgE (IU/mL) for 16 weeks in addition to stable BDP therapy.

MEASUREMENTS AND RESULTS

Univariate logistic regression was performed to explore baseline variables predictive of best response. Various aspects of response (reduced symptom scores, reduced usage of rescue medication, improved lung function, improved quality of life [QoL]) were explored as well as a composite definition of response (response in at least one of these four aspects with no asthma exacerbation during 16 weeks of treatment). Time to onset of response as well as the ability to predict eventual response were also determined for the composite definition of response. A consistent pattern of predictive covariates was seen over all definitions of response (except for QoL). For the composite definition, a history of emergency asthma treatment in the past year was the factor most predictive (p = 0.015) of best response on active treatment (response rate for those with such history was 67% for omalizumab and 42% for placebo; for those without a history the response rates were 63% and 54%, respectively). Another factor predictive of best response on active treatment was high BDP dose (p = 0.037; response rate for those treated with >or= 800 micro g/d was 65% for omalizumab and 40% for placebo; for those treated with < 800 micro g/d, the response rates were 63% and 55%, respectively). A low FEV(1) was also predictive (p = 0.072; response rates for those with FEV(1) <or= 65% predicted were 60% for omalizumab and 40% for placebo; for those with FEV(1) >or= 65% predicted, the response rates were 67% and 53%, respectively). Seventy-six percent of patients had at least one of these factors. This subgroup showed odds of being a responder (composite definition) 2.25 times higher (95% confidence interval, 1.68 to 3.01) than placebo. Some 38% of patients treated with omalizumab showed a response (composite definition) at the first evaluation time point at 4 weeks, increasing to 64% at week 16 (vs 48% for placebo; p < 0.001). Among omalizumab responders at 16 weeks, only 61% had responded at 4 weeks whereas 87% had responded at 12 weeks.

CONCLUSIONS

Patients who benefit most when omalizumab is administered as add-on therapy are those receiving high doses of BDP, those with a history of frequent emergency asthma treatment, and those with poor lung function. Patients should be treated with omalizumab for a minimum duration of 12 weeks.

Exhaled nitric oxide in children with asthma receiving Xolair (omalizumab), a monoclonal anti-immunoglobulin E antibody

OBJECTIVE

To evaluate the effect of a humanized monoclonal antibody to immunoglobulin E, omalizumab (Xolair, Novartis Pharmaceuticals, East Hanover, NJ; Genentech Inc, South San Francisco, CA), on airway inflammation in asthma, as indicated by the fractional concentration of exhaled nitric oxide (FE(NO)), a noninvasive marker of airway inflammation. Xolair was approved recently by the US Food and Drug Administration for moderate-to-severe allergic asthma in adolescents and adults.

STUDY DESIGN

As an addendum at 2 sites to a randomized, multicenter double-blind, placebo-controlled trial, FE(NO) was assessed in children with allergic asthma over 1 year. There were 3 consecutive study periods: 1) stable dosing of inhaled beclomethasone dipropionate (BDP) when the dose was optimized (period of 16 weeks); 2) inhaled steroid-reduction phase (period of 12 weeks), during which BDP was tapered if subjects remained stable; and 3) open-label extension phase, during which subjects receiving placebo were switched to active omalizumab (period of 24 weeks). The primary outcome was area under the FE(NO) versus time curve (AUC) for adjusted FE(NO), defined as the ratio of FE(NO) at each time point compared with the value at baseline.

RESULTS

Twenty-nine subjects participated and were randomized to omalizumab (n = 18) and placebo (n = 11) treatment groups in a 2:1 ratio dictated by the main study. There was a significant difference for age, resulting in a difference in absolute forced expiratory volume in 1 second but no difference in asthma severity based on the forced expiratory volume in 1 second percentage predicted. Baseline BDP dose was comparable between groups, as were baseline values of mean FE(NO) (active: 38.6 +/- 25.6 ppb; placebo: 52.7 +/- 52.9 ppb). The degree of BDP dose reduction during the steroid-reduction and open-label phases was equivalent between the omalizumab and placebo-treated groups; subjects in the omalizumab- and placebo-treated groups had reduced their BDP dose by an average of 51% and 60%, respectively, at the end of the steroid-reduction phase and by 68% and 94%, respectively, by the end of the open-label period. In the active and placebo groups, 44% and 27% and 75% and 73% of subjects had stopped use of inhaled corticosteroids at the end of the steroid-reduction and open-label phases, respectively. There was no significant difference between the active and placebo groups during the steroid-stable phase for AUC of adjusted nitric oxide (1.31 +/- 1.511 vs 1.45 +/- 0.736). However, during the steroid-reduction phase, the variability of adjusted FE(NO) in the placebo-treated group was greater than that of the omalizumab-treated group at most visits, with a significant difference between groups for AUC of adjusted nitric oxide (0.88 +/- 0.69 vs 1.65 +/- 1.06). FE(NO) fell from 82.1 +/- 55.6 ppm at the end of the steroid-reduction phase to 33.3 +/- 21.6 ppb at the end of the open-label period in the placebo group who were placed on active omalizumab. This decrease occurred while the mean dose of BDP remained very low. Analysis of FE(NO) over 52 weeks of omalizumab treatment in the active group demonstrated that there was a significant reduction from baseline to the end of the open-label period (41.9 +/- 29.0 to 18.0 +/- 21.8 ppb) despite a high degree of steroid reduction.

CONCLUSION

In this preliminary study based on FE(NO), a noninvasive marker of airway inflammation, treatment with omalizumab may inhibit airway inflammation during steroid reduction in children with allergic asthma. The degree of inhibition of FE(NO) was similar to that seen for inhaled corticosteroids alone, suggesting an antiinflammatory action for this novel therapeutic agent in asthma. This is in keeping with recent evidence that omalizumab inhibits eosinophilic inflammation in induced sputum and endobronchial tissue.

Anti-IgE for chronic asthma in adults and children

BACKGROUND

Omalizumab is a recombinant humanised monoclonal antibody directed against immunoglobulin E (IgE) to inhibit the immune system's response to allergen exposure. Omalizumab is directed against the binding site of IgE for its high affinity Fc receptor. It prevents free serum IgE from attaching to mast cells and other effector cells and prevents IgE mediated inflammatory changes.

OBJECTIVES

To determine the efficacy of anti-IgE in patients with allergic asthma

SEARCH STRATEGY

We searched the Cochrane Airways Group Asthma trials register (February 2003) for potentially relevant studies.

SELECTION CRITERIA

Randomised controlled trials examining anti-IgE administered in any manner for any duration.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed study quality and extracted and entered data. Three modes of administration were identified from the published literature (inhaled, intravenous and subcutaneous injection). Subgroup analysis was performed by asthma severity. Data were extracted from published and unpublished sources.

MAIN RESULTS

Eight trials were included in the review, contributing a total of 2037 mild to severe allergic asthmatic participants with high levels of IgE. Treatment with intravenous and subcutaneous Omalizumab significantly reduced free IgE compared with placebo. Omalizumab led to a significant reduction in inhaled steroid consumption compared with placebo: -114 mcg/day (95% CI -150 to -78.13, two trials). There were significant increases in the number of participants who were able to reduce steroids by over 50%: odds ratio (OR) 2.50, 95% confidence interval (CI) 2.02 to 3.10 (four trials); or completely withdraw their daily steroid intake: OR 2.50, 95%CI 2.00 to 3.13 (four trials). Participants treated with Omalizumab were less likely to suffer an asthma exacerbation with treatment as an adjunct to steroids (OR 0.49, 95%CI 0.38 to 0.64, four trials), or as a steroid tapering agent (OR 0.47, 95% CI 0.37 to 0.60, four trials).

REVIEWERS' CONCLUSIONS

Omalizumab was significantly more effective than placebo at increasing the numbers of patients who were able to reduce or withdraw their inhaled steroids, but the mean difference in steroid consumption achieved with Omalizumab was of debatable clinical value. The impressive effects observed in control groups bring into question the true effect of Omalizumab. Omalizumab was effective in reducing asthma exacerbations as an adjunctive therapy to inhaled steroids. Omalizumab was well tolerated, although the safety profile requires longer term assessment. Patient and physician assessment of the drug was positive. Further assessment in paediatric and severe adult populations is necessary, as is double-dummy comparison with inhaled corticosteroids.

The need for pediatric studies of allergy and asthma medications

For many years, clinicians have accepted the fact that most medications do not have dosing guidelines for children younger than 12 years of age. Recently, there has been a great effort to correct this deficiency. With the introduction of the 1997 Food and Drug Administration Modernization Act, a provision was established to grant additional market exclusivity to pharmaceutical firms that performed the required studies that would lead to improved labeling of medications for children. This effort has resulted in a significant advance for the management of asthma and allergic disorders in children. Several allergy and asthma medications are now approved for use in children as young as 1 year of age, with studies currently being conducted in younger age groups. In this review, we discuss the background for this effort and the continuing impact it will have on the future management of allergy and asthma in children.

Pharmacology of airway inflammation in asthma and COPD

The current asthma therapies are not cures and symptoms return soon after treatment is stopped even after long term treatment. Although inhaled glucocorticoids are highly effective in controlling airway inflammation in asthma, they are ineffective in the small group of patients with glucocorticoid-dependent and -resistant asthma. With very few exceptions, COPD is caused by tobacco smoking, and smoking cessation is the only truly effective treatment of COPD available. Current pharmacological treatment of COPD is unsatisfactory, as it does not significantly influence the severity of the disease or its natural course. Glucocorticoids are scarcely effective in COPD patients without concomitant asthma. Bronchodilators improves symptoms and quality of life, in COPD patients, but, with the exception of tiotropium, they do not significantly influence the natural course of the disease. Theophylline is the only drug which has been demonstrated to have a significant effect on airway inflammation in patients with COPD. Here we review the pharmacology of currently used antiinflammatory therapies for asthma and COPD and their proposed mechanisms of action. Recent understanding of disease mechanisms in severe steroid-dependent and -resistant asthma and in COPD, has lead to the development of novel compounds, which are in various stages of clinical development. We review the current status of some of these new potential drugs.

Links between rhinitis and asthma

There is compelling evidence of a close relationship between the upper and lower airways in asthma and rhinitis. Rhinitis is present in the majority of patients with asthma, and a significant minority of patients with rhinitis have concomitant asthma. Similarities between the two conditions occur in the nature of the inflammation present in the target tissues. A common initiating step in the inflammatory process of allergic airways disease is the presence of immunoglobulin E providing an adaptor molecule between the offending allergen and inflammatory cell activation and mediator release. Differences in the two conditions arise largely from the structural differences between the nose and the lungs. In an asthmatic, concomitant allergic rhinitis increases healthcare costs and further impairs quality of life. The presence of rhinitis should always be investigated in children and young adults with asthma. Subjects with allergic rhinitis have an increased risk of developing asthma and may form a suitable population for secondary intervention to interrupt the 'allergic march'.

Omalizumab, an anti-IgE antibody, in the treatment of adults and adolescents with perennial allergic rhinitis

BACKGROUND

Treatment with omalizumab, an anti-IgE antibody, improves symptoms and quality of life in patients with seasonal allergic rhinitis but has not previously been investigated in patients with perennial symptoms.

OBJECTIVE

To investigate the efficacy, safety, and tolerability of omalizumab in the treatment of perennial allergic rhinitis (PAR).

METHODS

Two hundred eighty-nine patients (aged 12 to 70 years) with moderate-to-severe symptomatic PAR were randomized to 16 weeks' double-blind subcutaneous treatment with either placebo (n = 145) or omalizumab (at least 0.016 mg/kg/IgE [IU/mL] per 4 weeks; n = 144). The primary efficacy variable was the mean daily nasal severity score, as determined from patient daily diary cards. Secondary efficacy variables included use of rescue antihistamine, rhinoconjunctivitis-specific quality of life (RQoL), and patients' evaluation of treatment efficacy. Safety and tolerability were evaluated from adverse event reports and laboratory safety parameters.

RESULTS

Throughout 16 weeks of treatment, the mean daily nasal severity score was significantly lower in omalizumab-treated patients than with placebo (P < 0.001). The improvement in symptoms when taking omalizumab was paralleled by a reduction in use of rescue antihistamine (P < or = 0.005 overall) and improved RQoL relative to placebo. Patients' evaluation of treatment efficacy significantly favored omalizumab over placebo (P = 0.001). Omalizumab therapy was well tolerated. There were no safety concerns.

CONCLUSIONS

Omalizumab was safe and well tolerated in the treatment of patients with PAR, providing effective control of symptoms and improved RQoL while simultaneously minimizing reliance on rescue antihistamines.