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

Eosinophils in bronchial mucosa of asthmatics after allergen challenge: effect of anti-IgE treatment

BACKGROUND

Anti-IgE, omalizumab, inhibits the allergen response in patients with asthma. This has not been directly related to changes in inflammatory conditions. We hypothesized that anti-IgE exerts its effects by reducing airway inflammation. To that end, the effect of anti-IgE on allergen-induced inflammation in bronchial biopsies in 25 patients with asthma was investigated in a randomized, double-blind, placebo-controlled study.

METHODS

Allergen challenge followed by a bronchoscopy at 24 h was performed at baseline and after 12 weeks of treatment with anti-IgE or placebo. Provocative concentration that causes a 20% fall in forced expiratory volume in 1 s (PC(20)) methacholine and induced sputum was performed at baseline, 8 and 12 weeks of treatment. Changes in the early and late responses to allergen, PC(20), inflammatory cells in biopsies and sputum were assessed.

RESULTS

Both the early and late asthmatic responses were suppressed to 15.3% and 4.7% following anti-IgE treatment as compared with placebo (P < 0.002). This was paralleled by a decrease in eosinophil counts in sputum (4-0.5%) and postallergen biopsies (15-2 cells/0.1 mm(2)) (P < 0.03). Furthermore, biopsy IgE+ cells were significantly reduced between both the groups, whereas high-affinity IgE receptor and CD4+ cells were decreased within the anti-IgE group. There were no significant differences for PC(20) methacholine.

CONCLUSION

The response to inhaled allergen in asthma is diminished by anti-IgE, which in bronchial mucosa is paralleled by a reduction in eosinophils and a decline in IgE-bearing cells postallergen without changing PC(20) methacholine. This suggests that the benefits of anti-IgE in asthma may be explained by a decrease in eosinophilic inflammation and IgE-bearing cells.

Treatment of allergic bronchopulmonary aspergillosis (ABPA) in CF with anti-IgE antibody (omalizumab)

Allergic bronchopulmonary aspergillosis (ABPA) results from IgE induced pulmonary response to aspergillus species. Recognition and management of ABPA is challenging in cystic fibrosis (CF) patients because changes in symptoms, lung function and chest radiograph are similar to that seen in CF related pulmonary infection. Standard therapy for ABPA includes systemic steroids and adjunctive use of antifungal agents. Little has been published regarding the use of monoclonal anti-IgE antibody in those with ABPA. We report a CF patient with her third exacerbation of ABPA who was treated with monoclonal anti-IgE (omalizumab) antibody; she had unfavorable side effects with prednisone therapy. This therapy resulted in improvement of pulmonary symptoms and lung function not achieved with antibiotics or prednisone alone.

Immunoglobulin E antibodies enhance pulmonary inflammation induced by inhalation of a chemical hapten

BACKGROUND

Occupational exposure to chemicals is an important cause of asthma. Recent studies indicate that IgE antibodies enhance sensitization to chemicals in the skin.

OBJECTIVE

We investigated whether IgE might similarly promote the development of airway inflammation following inhalation of a contact sensitizer.

METHODS

A model of chemical-induced asthma is described in which introduction of the low-molecular-weight compound, trinitrobenzene sulphonic acid (TNBS), via the respiratory tract was used for both sensitization and challenge. The role of IgE antibodies in the immune response to inhaled TNBS in this model was assessed by comparing the responses of wild-type (WT) and IgE-deficient (IgE(-/-)) mice on the BALB/c background. Reconstitution of circulating IgE levels by intravenous injection of IgE antibodies into IgE(-/-) mice before sensitization was performed to confirm the role of IgE in any differences observed between the responses of WT and IgE(-/-) mice.

RESULTS

Intranasal challenge of TNBS-sensitized (but not sham-sensitized control mice) induced intense pulmonary inflammation. Macrophages, eosinophils and lymphocytes, including T, B, natural killer and natural killer T cells, were recruited to the airway and the animals displayed bronchial hyperresponsiveness (BHR) to methacholine. Serum levels of murine mast cell protease-1 (mMCP-1) were elevated suggesting mast cell activation. In contrast, the development of airway inflammation, recruitment of lymphocytes, induction of BHR and production of mMCP-1 were all significantly attenuated in IgE-deficient mice. Reconstitution of IgE(-/-) mice with IgE (of unrelated antigen specificity) before sensitization partially restored these features of asthma.

CONCLUSION

Our data indicate that IgE antibodies non-specifically enhance the development of airway inflammation induced by exposure to chemical antigens.

Specific IgE serum concentration is associated with symptom severity in children with seasonal allergic rhinitis

BACKGROUND

The impact of allergen-specific and total IgE serum levels before and during the pollen season on symptom severity as well as efficacy of treatment with anti-IgE requires further delineation.

METHODS

Birch and grass pollen allergic patients aged 6-17 years with seasonal allergic rhinitis (SAR) were analyzed for the association of IgE serum concentration with symptom severity and rescue medication use (combination: symptom load, SL) during the grass pollen season. Reference group A (n = 53) received placebo, while group B (n = 54) received Omalizumab (anti-IgE) monotherapy before and during the grass pollen season.

RESULTS

Patients on placebo with high baseline specific grass pollen IgE (>50 kU/l) had a significantly higher SL compared with those with low IgE levels (< or =50 kU/l): SL 1.28 vs 0.61, P = 0.015. This association was nonexistent in patients treated with anti-IgE. In contrast, baseline total IgE levels did not correlate with SL in any group. Patients with anti-IgE treatment and high free total IgE levels (>16.7 ng/ml) had a significantly higher SL compared with those with low free total IgE levels (< or =16.7 ng/ml): SL 0.63 vs 0.23, P = 0.031.

CONCLUSIONS

Baseline specific IgE, but not total IgE, is associated with symptom severity during the pollen season in children with SAR. Likewise, the symptom load in SAR patients with anti-IgE correlates with free total IgE levels. Although further research in larger populations is needed to confirm our findings, our data suggest that specific IgE can be used as a parameter for patient selection for this kind of treatment.

Asthma 2008: targeting immunoglobulin E to achieve disease control

Traditionally, practice guidelines have recommended a step-wise approach to treatment based on asthma severity and lung function. However, increasing evidence suggests that asthma may not be adequately controlled in many patients with moderate-to-severe disease despite aggressive therapy, and that regularly evaluating the level of asthma control achieved in individual patients may be more effective than disease severity in guiding treatment decisions. This is reflected in updated asthma guidelines from the National Asthma Education and Prevention Program, which advocate regular assessment of asthma control in terms of the current impairment and future risk associated with the disease. Guideline-recommended options for patients with persistent, moderate-to-severe immunoglobulin E (IgE)-mediated asthma have recently been enhanced by the inclusion of omalizumab. This change is based on growing evidence for the central role of IgE in airway inflammation and asthma and the clinical effectiveness of blocking IgE with omalizumab, a recombinant humanized monoclonal antibody. Omalizumab significantly reduced asthma exacerbations and improved lung function and symptoms in randomized controlled studies of patients inadequately controlled on inhaled corticosteroids plus long-acting beta(2)-agonist therapy; these benefits for reducing asthma impairment and risk were maintained during steroid dose reductions. Omalizumab is well tolerated, although patients should be monitored for possible rare anaphylactic reactions.

What is new in the management of childhood asthma?

The prevalence of asthma has increased in developed countries. The efficacy of available drugs in those with severe persistent disease is limited. This has led to a renewed search for the reasons for failures of the existing treatment and for novel concepts. Treatment with inhaled corticosteroids, and to a much lesser extent theophylline, can reduce the survival of inflammatory cells including eosinophils. Emerging trends in treatments for asthma could include strategies to alter the cytokine/chemokine balance. It is evident that the current ICS are already very efficient and safe, it will be difficult to introduce further improved formulations. Perhaps the most fruitful effort shall be in developing patient friendly easy to use targeted delivery systems. The newer therapies are planned for the several upstream targets and may have potential to prevent the disease. Various potential therapies are being worked upon like-targeting prevention of T cell activation, modulation of Th-1/Th-2 differentiation, inhibition of Th-2 related cytokines, Th-1/Th-2 modulation, inhibition of downstream mediators etc. The new strategy shall perhaps lie with matching the patients and their disease with the most suitable therapy.

Preferences and utilities for the symptoms of moderate to severe allergic asthma

INTRODUCTION

Patients with moderate to severe allergic asthma have persistent poorly controlled asthma despite inhaled or systemic corticosteroid therapy. New therapies are becoming more widely available to treat such patients, but their value needs to be formally assessed in an economic evaluation. Within a publicly funded health care system such an analysis should reflect societal preferences when measuring treatment benefits. The aim of this study was to elicit societal preferences for the symptom burden associated with moderate to severe allergic asthma.

METHOD

Existing daily symptom diary data from a clinical trial were used to develop health state descriptions for evaluation in a standard gamble interview. Five health states were produced that reflected five distinct levels of control ranging from 'complete control of asthma' to 'worsening of asthma', as defined by another outcome measure. The symptom diary data were also used as attributes in a discrete choice experiment (DCE) to estimate willingness to pay for improvements in symptoms. Members of the general public (n = 101) completed the interview.

RESULTS

Thirteen participants failed the consistency checks and were excluded from the analysis. Societal utility ratings for the health states ranged from 0.71 (worsening of asthma) to 0.78 (complete control of asthma). The participants were also willing to pay 160 pounds a month for the avoidance of all symptoms.

CONCLUSIONS

The range of utility values (0.71-0.78) demonstrates the severity of moderate to severe allergic asthma. However the spread of scores between complete control of asthma and worsening of asthma was lower than was expected. The community sample placed only a moderate value on the avoidance of all asthma symptoms in the DCE survey. The results suggest that the community sample may not have fully understood the benefits of control over asthma symptoms and the limitations such symptoms can impose on everyday life.

Effectiveness of omalizumab in patients with inadequately controlled severe persistent allergic asthma: an open-label study

BACKGROUND

In a 1-year, randomized, open-label study in patients with moderate-to-severe allergic (immunoglobulin E (IgE)-mediated) asthma, adding omalizumab to best standard care (BSC) significantly improved efficacy outcomes compared with BSC alone (control). We assessed the efficacy of omalizumab in the subgroup of patients with inadequately controlled severe persistent allergic asthma despite high-dose inhaled corticosteroids (ICS) plus a long-acting beta(2)-agonist (LABA), which reflects the European Union (EU) label population.

METHODS

Efficacy outcomes included annual asthma exacerbation rate, annual asthma deterioration-related incident (ADRI) rate, % predicted forced expiratory volume in 1 s (FEV(1)), asthma symptoms (Wasserfallen score) and quality of life (Mini Asthma Quality of Life Questionnaire (Mini-AQLQ)), which were compared in the omalizumab and control groups. Outcomes were also determined for omalizumab-treated patients judged to have responded to therapy (> or = 0.5-point improvement in Mini-AQLQ overall score at 27 weeks).

RESULTS

In total, 164 patients (omalizumab, n=115; control, n=49) were receiving high-dose ICS plus a LABA. Annual asthma exacerbation rate was significantly reduced by 59% in the omalizumab group vs. control (1.26 vs. 3.06; P<0.001). ADRI rate was significantly reduced by 40% in the omalizumab group compared with control (5.61 vs. 9.40; P<0.05). Significant improvements were also seen in % predicted FEV(1) (71% vs. 60%; P<0.001), change from baseline in asthma symptom scores (-6.7 vs. 0.5; P<0.05) and Mini-AQLQ overall score (1.32 vs. 0.17; P<0.001). In omalizumab-treated patients, 71/102 (70%) were judged to have responded to therapy. In these Mini-AQLQ-assessed responders, exacerbation rate was reduced by 64% vs. control (1.12 vs. 3.06; P<0.001), ADRI rate was reduced by 50% vs. control (4.71 vs. 9.40; P<0.01). Percent predicted FEV(1) (73% vs. 60%; P<0.001), change from baseline in asthma symptom scores (-8.1 vs. 0.5; P<0.001) and Mini-AQLQ overall score (1.81 vs. 0.17; P<0.001) were also further significantly improved vs. control.

CONCLUSIONS

Adding omalizumab to BSC is efficacious in patients with inadequately controlled severe persistent allergic asthma despite high-dose ICS plus a LABA (EU label population), with further efficacy observed in patients judged to have responded to therapy which may more accurately illustrate the actual benefit of omalizumab therapy in clinical practice. The naturalistic setting of this study confirms the benefits observed in double-blind randomized clinical trials.

Omalizumab: the evidence for its place in the treatment of allergic asthma

INTRODUCTION

Asthma is a chronic inflammatory airways disease associated with reversible airflow obstruction and bronchial hyperresponsiveness. Asthma is prevalent worldwide and results in significant morbidity, mortality, and healthcare costs, the majority of which arise from those with severe disease. Omalizumab is a monoclonal antibody to immunoglobulin E (IgE) that has been developed for the treatment of severe persistent allergic (IgE mediated) asthma.

AIMS

The aim of this review is to evaluate the available clinical evidence on omalizumab to determine the role it has to play in the treatment of persistent allergic asthma.

EVIDENCE REVIEW

There is clear evidence to show that omalizumab is effective in reducing the rate of asthma exacerbations, inhaled corticosteroid dose, and the need for rescue medication in patients with allergic asthma. Clinical data indicate beneficial effects on patient-reported symptoms and perceived quality of life, as well as a reduction in unscheduled healthcare visits. There is little evidence to suggest omalizumab may enhance lung function or reduce the requirement for oral corticosteroids. Omalizumab has a favorable safety profile, although anaphylaxis has occurred. A study in children showed similar results to those achieved in adults and adolescents, with fewer asthma exacerbations and school days missed. Omalizumab may be cost effective in patients when used as add-on therapy to inhaled corticosteroids and long-acting beta(2) agonists (LABA).

PLACE IN THERAPY

Omalizumab is an effective add-on therapy to inhaled corticosteroids and LABAs in adults and adolescents with severe persistent allergic asthma. Currently there is insufficient evidence to support the use of omalizumab in children.

An evaluation of the cost-effectiveness of omalizumab for the treatment of severe allergic asthma

Omalizumab is the first licensed anti-immunoglobulin (Ig) E antibody shown to be effective for treatment of allergic (IgE-mediated) asthma. Recent international guidelines recommend omalizumab as add-on treatment to fixed dose inhaled corticosteroid (ICS) and long-acting beta(2)-agonist (LABA) combination therapy. However, omalizumab is more expensive than other current asthma treatments and health and reimbursement authorities are increasingly demanding evidence of economic benefit to support pricing and formulary listing. The aims of this article are to (i) summarize data on the human and economic burden of severe asthma, (ii) summarize the efficacy data obtained for omalizumab in clinical trials in patients with inadequately controlled severe persistent allergic asthma despite high-dose ICS plus a LABA, and (iii) discuss the cost-effectiveness evidence published for omalizumab in this patient population. A wealth of evidence exists highlighting that the health, economic and societal burden of asthma is considerable and is highly skewed towards patients with severe asthma, particularly when asthma is inadequately controlled. Omalizumab is clinically beneficial in patients with severe persistent allergic asthma despite high-dose ICS plus a LABA, particularly in a subgroup of patients who respond to therapy. In patients who respond to therapy, the cost-effectiveness of omalizumab compares well with other biologic treatments for chronic illness.

Reduction of the total IgE level by omalizumab in children and adolescents

BACKGROUND

Current data from clinical studies show that patients with severe allergic asthma experience a significant improvement from omalizumab. The early and late allergic reactions are inhibited by formation of complexes with free circulating immunoglobulin E (IgE), independent of which antigen activates the allergic cascade. The dosage of omalizumab depends on body weight and IgE level, yet no parameter has been established to guide dosage changes during therapy. The aim of this study was to investigate the value of the determination of total IgE by ADVIA Centaur assay to monitor the therapy progress.

PATIENTS AND METHODS

Nine patients, 8 to 17 years of age, received therapy with omalizumab due to severe allergic bronchial asthma. In addition, the patients had pronounced rhinoconjunctivitis, food allergy, insect sting allergy, and/or neurodermitis. The total IgE in the serum (Sandwich-Immunoassay ADVIA Centaur) was measured in the patients once monthly before each omalizumab injection as a potential progress parameter.

RESULTS

Six months after the beginning of therapy with omalizumab, a significant decrease of the total IgE concentration was found, in comparison to the baseline values (p < 0.01). In all patients, the tolerability of omalizumab was very good; there was a reduction in the frequency of the asthma exacerbations and rescue medications. The dosage of inhaled glucocorticoids could be lowered. All patients reported a clearly improved quality of life.

CONCLUSIONS

The increase of the total IgE concentrations after administration of omalizumab described in the literature could not be confirmed. The value of total serum IgE as a progress parameter should be investigated in controlled studies with regard to sensitivity and specificity of the respective assays. The establishment of a test procedure for therapeutic monitoring appears urgently necessary, so that the appropriate dosage of omalizumab is applied in children and adolescents. Patients receiving omalizumab therapy should be closely monitored.

Targeting airway inflammation in asthma: current and future therapies

Asthma is a chronic inflammatory disease of the airway that requires long-term antiinflammatory therapy. Inhaled corticosteroids (ICSs) are recommended for first-line treatment of persistent disease, but not all patients achieve asthma control even when these agents are used in high doses and in combination with other medications, including a long-acting beta(2)-agonist or a leukotriene modifier. Such patients may require additional therapy. As information about asthma pathophysiology and inflammatory phenotypes continues to increase, and additional antiinflammatory options become available, it may be possible to target antiinflammatory therapy to various aspects of the disease and consequently to improve the treatment of patients with inadequate responses to standard ICS-based therapy. Several novel antiinflammatory therapies are in different stages of clinical development. The most clinically advanced of these is omalizumab, a recombinant humanized monoclonal antibody that specifically targets IgE and is indicated for patients with moderate-to-severe asthma caused by allergies. Omalizumab has demonstrated efficacy in patients with moderate-to-severe asthma and documented evidence of allergen sensitivity. Other key therapy options in clinical development either target proinflammatory cytokines (eg, interleukin-4 and tumor necrosis factor-alpha) or inflammatory cells (eg, T-helper type 2 cells and eosinophils). This review provides an overview of the current and future approaches targeting airway inflammation in patients with 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).

Add-on omalizumab improves day-to-day symptoms in inadequately controlled severe persistent allergic asthma

BACKGROUND

Omalizumab is efficacious in the treatment of moderate-to-severe and severe persistent allergic (immunoglobulin E-mediated) asthma, reducing exacerbations, emergency visits and improving quality of life (QoL). However, as exacerbations are relatively infrequent, assessment of efficacy on day-to-day symptoms is warranted.

AIMS

To investigate the effect of add-on omalizumab on day-to-day symptoms, and how they correlate with QoL in severe persistent asthma.

METHODS

The correlation between asthma symptom scores and QoL [Asthma Quality of Life Questionnaire (AQLQ)] was assessed. Symptom-free days (total symptom score = 0) and symptom-controlled days (definition 1: total symptom score </=1; and definition 2: morning peak expiratory flow >/=90% of baseline, daytime asthma score </=1 and night-time asthma score = 0) were compared between the omalizumab-treated group, omalizumab responders and placebo.

RESULTS

Four hundred and nineteen patients (omalizumab, n = 209; placebo, n = 210) were included in the efficacy analyses, and 61% (118/195) of patients with response data were classified as responders. Total symptom score strongly correlated with AQLQ overall and symptom scores and individual domains. AQLQ overall score correlated well with symptom scores. Responders had significantly more symptom-free days than the omalizumab-treated and placebo groups (45.8%, 37.2% and 22.6% respectively), and more symptom-controlled days (definition 1: 56.1%, 47.9% and 35.3%, respectively, and definition 2: 50.8%, 43.9% and 28.0%, respectively).

CONCLUSIONS

In patients with inadequately controlled severe persistent asthma, day-to-day symptoms correlate well with QoL. Add-on omalizumab significantly improves day-to-day symptoms compared with placebo. Further improvement in responders confirms the physician's assessment as a response measure.

Asthma overview

This article presents our current understanding of the biological heterogeneity of asthma and reviews some of the key features of the latest proposed recommendations of the National Asthma Education and Prevention Program Guidelines. The diagnosis of asthma is based on such clinical features as variable airflow obstruction that is partially if not fully reversible and airway hyperresponsiveness that predisposes to episodic bronchospasm following exposure to a variety of triggers. The underlying inflammation and airway biology of asthma is heterogeneous and is part of the explanation for the variable response to therapy. New biologics that help to characterize patients according to their underlying biology will aid in making better choices for treatment. New asthma guidelines emphasize the importance of regular monitoring.

Immunomodulators for allergic respiratory disorders

New knowledge about the pathogenesis of allergic and immunologic diseases has led to a variety of novel targeted therapeutic approaches. Many immunomodulators are currently under development for the therapy of asthma and allergic and immunologic diseases and are undergoing human clinical trials. The study of immunomodulators in human subjects is ultimately required to determine their therapeutic utility because several agents showing promise in in vitro and animal models have failed in human studies. Novel therapeutic approaches include Toll-like receptor 4 and 9 agonists, immunostimulatory oligodeoxynucleotides, oral and parenterally administered cytokine blockers, and specific cytokine receptor antagonists. Transcription factor modulators targeting syk kinase, peroxisome proliferator-activated receptor gamma, and nuclear factor kappaB are also being evaluated for the treatment of allergic diseases, especially asthma. The anti-IgE mAb omalizumab is already used for the treatment of allergic asthma, but its potential role for other allergic diseases has yet to be clearly defined. Overall, the development of new agents that inhibit specific immunopathogenic mechanisms holds promise for beneficial outcomes for patients with the least amount of risk. However, agents that are too specific in their targets might not exhibit therapeutic benefits because of the redundancy of the immune system and the heterogeneity of diseases such as asthma. The goal of this review is to summarize the data from human clinical trials with immunomodulators, discussing the rationale for their use, efficacy results, and putative adverse events associated with them.

Anti-IgE in severe persistent allergic asthma

Omalizumab is an mAb targeted against IgE. It reduces asthma exacerbations and symptoms and has low anaphylactic potential. In the placebo-controlled double-blind study, INNOVATE, omalizumab was used in the patient population with the greatest unmet clinical need, who being those meeting the Global Initiative for Asthma 2002 step 4 criteria for severe persistent asthma. When added to existing therapy, patients treated with omalizumab had a 26.2% lower rate of clinically significant asthma exacerbations, after an adjustment to take into account an observed pre-study imbalance in the exacerbation rate (P = 0.042). The Global Initiative for Asthma has recognized the role of anti-IgE therapy in treating patients with severe persistent asthma. Initiation of anti-IgE therapy is now recommended for these patients at step 4. Severe asthma has a major impact on health-care resource utilization. To date, treatment options have been limited in this target population. Omalizumab reduces symptoms, exacerbations and emergency visits in patients who are not adequately controlled on inhaled corticosteroids and long-acting beta agonists. It is a valuable therapeutic option, addressing an unmet need in the area of severe asthma.

Rationale for the major changes in the pharmacotherapy section of the National Asthma Education and Prevention Program guidelines

Numerous changes have been incorporated into the new National Asthma Education and Prevention Program's Expert Panel Report 3. In the pharmacotherapy section of the report, many of these changes are minor in that they do not alter the basic philosophy of treatment recommendations from the previous Expert Panel Report but only add new formulations, change dosing or dosage forms, or add discussion of risks. However, 4 major changes have been identified, and the rationales for 3 are discussed in detail here. The treatment of childhood asthma is divided into 2 distinct age groups, infants less than 5 years of age and children 5 to 12 years of age, because of the availability of more data suggesting differences in response in these patients, as well as a relative paucity of quality data in the younger patients. Omalizumab, a humanized mAb to IgE, is the only new entity approved for the treatment of asthma since the previous guidelines, and its recommendations were reviewed. The indication for combination therapy with inhaled corticosteroids and long-acting inhaled beta(2)-agonists (LABAs) has been modified in lieu of the recent black box warning concerning the increased risk of severe asthma exacerbations and death associated with LABA use. However, the inhaled corticosteroids/LABAs are still recommended for patients with moderate-to-severe persistent asthma. The rationale for the continued recommendation is provided.

[Application of humanized Anti-IgE antibodies (omalizumab). A new principle in the treatment of allergic diseases in ENT medicine]

Omalizumab is a humanized monoclonal anti-IgE antibody developed for the treatment of allergic diseases. It has demonstrated good efficacy in patients with intermittent and persisting allergic rhinitis and in patients with moderate-to-severe allergic asthma. Omalizumab results in a marked lowering of free IgE in serum and down-regulation of IgE receptors on circulating basophils. In addition, it reduces the inflow of eosinophils into nasal and bronchial tissue and the number of IgE-positive mast cells in the bronchial mucosa. Omalizumab treatment has also been shown to be associated with down-regulation of IgE receptors on circulating dendritic cells, suggesting that blocking IgE may also inhibit chronic aspects of allergic inflammation involving T cell-activation. Patients' clinical symptoms are attenuated and their quality of life improved by anti-IgE treatment with omalizumab; other medications effective in symptomatic treatment are therefore less necessary. Omalizumab's broad spectrum of efficacy emphasizes the central role of IgE in the allergic-inflammatory cascade. Further areas of applications in ENT medicine could be anticipated in other IgE-related illnesses, such as allergic rhinitis, food allergies, laryngitis and chronic allergy-related rhinosinusitis.

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.

Immunoglobulin E blockade in the treatment of asthma

Patients with moderate-to-severe asthma often have persistent symptoms despite aggressive pharmacotherapy, enthusiastic patient compliance, and proper technique in using delivery devices. Persistent symptoms have detrimental effects on patients' quality of life and result in a tremendous financial burden because of an increased utilization of health care resources. Guidelines from the National Asthma Education and Prevention Program list symptom prevention, near-normal lung function, and participation in activities (e.g., school, work) as goals of successful asthma therapy. The development of pharmacologic and biologic therapies that target different aspects of airway inflammation will help patients with persistent asthma symptoms achieve these goals. Immunoglobulin E (IgE) is increasingly recognized as a key component of asthma pathophysiology and contributes to both the early- and late-phase inflammatory cascade of the airways by inhibiting allergen-induced activation of mast cells. Both epidemiologic and clinical evidence support the use of IgE blockade for asthma treatment. Omalizumab is currently the only IgE-targeted therapy approved by the United States Food and Drug Administration for asthma treatment. The drug improves symptoms, reduces exacerbations, and improves quality of life in certain patient populations.

Allergic airways disease develops after an increase in allergen capture and processing in the airway mucosa

Airway mucosal dendritic cells (AMDC) and other airway APCs continuously sample inhaled Ags and regulate the nature of any resulting T cell-mediated immune response. Although immunity develops to harmful pathogens, tolerance arises to nonpathogenic Ags in healthy individuals. This homeostasis is thought to be disrupted in allergic respiratory disorders such as allergic asthma, such that a potentially damaging Th2-biased, CD4(+) T cell-mediated inflammatory response develops against intrinsically nonpathogenic allergens. Using a mouse model of experimental allergic airways disease (EAAD), we have investigated the functional changes occurring in AMDC and other airway APC populations during disease onset. Onset of EAAD was characterized by early and transient activation of airway CD4(+) T cells coinciding with up-regulation of CD40 expression exclusively on CD11b(-) AMDC. Concurrent enhanced allergen uptake and processing occurred within all airway APC populations, including B cells, macrophages, and both CD11b(+) and CD11b(-) AMDC subsets. Immune serum transfer into naive animals recapitulated the enhanced allergen uptake observed in airway APC populations and mediated activation of naive allergen-specific, airway CD4(+) T cells following inhaled allergen challenge. These data suggest that the onset of EAAD is initiated by enhanced allergen capture and processing by a number of airway APC populations and that allergen-specific Igs play a role in the conversion of normally quiescent AMDC subsets into those capable of inducing airway CD4(+) T cell activation.

Immunoglobulin E-mediated airway inflammation is active in most patients with asthma

PURPOSE

To review the role of immunoglobulin E (IgE)-mediated inflammation in the pathogenesis of asthma, limitations of standard therapies, and IgE as a logical target for therapy with omalizumab aimed at attaining asthma symptom control.

DATA SOURCES

Review of worldwide scientific literature on the role of IgE-mediated inflammation in patients with asthma, supplemented with a clinical case study.

CONCLUSIONS

Clinical trials point to an important role for IgE blocker therapy as an add-on to current therapy to reduce exacerbations and corticosteroid use and to improve quality of life in patients with moderate-to-severe asthma. Omalizumab, a monoclonal antibody that binds IgE, has been shown to be an effective, well-tolerated treatment in these patients.

IMPLICATIONS FOR PRACTICE

A significant number of patients with moderate-to-severe asthma do not achieve asthma symptom control, despite adhering to current guidelines-based standards of therapy, including the use of inhaled corticosteroids, beta-agonists, and leukotriene modifiers. None of these therapies directly addresses IgE-mediated inflammation. Therefore, patients with persistent symptoms of moderate-to-severe asthma should be evaluated and considered for therapy with the IgE blocker omalizumab.

Many asthma patients experience persistent symptoms despite appropriate clinical and guideline-based treatment with inhaled corticosteroids

PURPOSE

To review possible reasons for persistence of asthma symptoms despite appropriate use of clinical and guideline-based treatments, including the use of inhaled corticosteroids.

DATA SOURCES

Review of the worldwide scientific literature on factors related to persistent symptoms in patients with asthma.

CONCLUSIONS

Patients with asthma may not respond as expected to therapy because of factors that include poor adherence, improper inhaler technique, persistent exposure to symptom triggers, and limitations of current standard therapy, including steroid insensitivity or the steroid plateau effect. Persistent symptoms may also be associated with IgE-mediated airway inflammation, as current standard asthma therapies do not directly address the IgE-mediated component of the inflammatory cascade. Asthma is a complex disease and its treatment requires the full cooperation and participation of the patient.

IMPLICATIONS FOR PRACTICE

Healthcare professionals can play a key role by educating patients and their family members about the nature of asthma and rationale for treatment, supporting the importance of strict adherence to prevention measures and the prescribed treatment regimen.

[Economic aspects of severe asthma]

Severe asthma and difficult-to-treat asthma are major issues in public health, given the mortality and morbidity they induce and their detrimental effects on patients' quality of life. The economic consequences should not be overlooked either. Published studies suggest that asthma-related medical resource use increases with the degree of asthma severity. Medical resource use incurred by severe (and/or difficult-to-treat) asthma could be reduced in part by more appropriate treatment, better patient education, improved coordination of disease management and treatment of comorbid diagnoses. The specific difficulties in the management of severe asthma and/or difficult-to-treat asthma must nonetheless be kept in mind. Recent new treatments appear promising, but their costs and indications in actual medical practice require better definition.

Anti-IgE in allergic asthma and rhinitis: an update

Allergic asthma and rhinitis imposes a huge burden in terms of treatment costs, productivity loss and hospital admissions. IgE plays a significant role in the manifestation of these conditions and the identification of a monoclonal antibody that binds to IgE provides clinicians another therapeutic strategy in the management of these conditions. Blocking the effects of IgE by omalizumab, a recombinant humanized monoclonal antibody that selectively binds to IgE has been shown to be a useful adjunct in the treatment of allergic asthma and rhinitis. Omalizumab is effective as a steroid reducing agent in patients with severe asthma and is successful in decreasing asthma exacerbations. Omalizumab was well tolerated in clinical trials, however, the potential long-term side effects need careful monitoring. The high cost of the molecule could make this a therapeutic option in a small proportion of patients in whom there is a large unmet need.

[Targeted immunologic therapies for severe asthma]

Better understanding of the cellular and molecular mechanisms of asthma have made it possible to envision a large number of new treatment targets. Clinical trials assessing some of these targets were recently published. The results of these trials were often disappointing. For example, parenteral administration of anti-interleukin-5 antibodies diminished bronchial eosinophilic inflammation but without improving either asthma symptoms or bronchial hyperreactivity. Other treatments are promising but have not yet been proved effective in patients with asthma: open studies with anti-TNF alpha antibodies are interesting but the efficacy of this treatment strategy remains uncertain and must be validated against placebo. The first targeted treatment approved for severe difficult-to-control allergic asthma is an anti-IgE monoclonal antibody (omalizumab).

Effectiveness of omalizumab (Xolair) in the first patients treated in real-life practice in France

OBJECTIVE

To describe omalizumab (Xolair) effectiveness in the first patients treated on compassionate grounds before its commercialisation in France.

METHODS

In a historic-prospective study, data were obtained by questionnaire from the physicians whose patients had received a nominative temporary use authorisation (ATU) for omalizumab from July 2003 to January 2006. Anonymised patient data regarding demographics, asthma-related treatments and events in the year previous to the start of omalizumab treatment as well as the details of omalizumab treatment itself were obtained at inclusion. Follow-up data at more than 3 months following inclusion were also obtained and regarded asthma-related treatment (including omalizumab), events and undesirable effects suspected to be linked to omalizumab treatment.

RESULTS

Data were obtained for 147 of the 154 patients treated via ATU. 31.3% received inappropriate monthly doses of omalizumab. Of the 28 patients (19%) who discontinued for unsatisfactory therapeutic effect, 7 were treated for less than the 16 weeks recommended to evaluate efficacy and 9 who were treated for a longer period of time were underdosed. During the treatment period and compared to the previous year, patients with follow-up data at 5 months or more had experienced 62% fewer exacerbations requiring oral corticosteroids, 65% fewer emergency department visits and 29% fewer hospitalisations per year. The nature of adverse effects reported was similar to that reported in omalizumab clinical trials.

CONCLUSION

Results strongly suggest that omalizumab in the first patients treated in real-life setting provided a similar benefit to that observed in clinical trials. Underdosing of patients may limit this therapeutic effect.

Pharmacotherapy of asthma

The pharmacotherapy of asthma is a complex and evolving topic. A detailed understanding of the pathophysiologic processes involved in the asthmatic response forms the basis for understanding the actions of drugs used to treat this condition. Likewise, a solid comprehension of the medicinal chemistry and pharmacologic properties of the numerous agents involved in the treatment of asthma is critical for rationalizing drug choices and understanding potential side effects. Asthma is addressed at several points in the PharmD curriculum at South University including in the Pathophysiology (quarter 2), Integrated Sequence III (quarter 6), and Critical Care (quarter 9) courses. Various teaching strategies are employed throughout, along with weekly case-based recitations. The content presented here includes a synopsis of the pathophysiology and pharmacology from our Integrated Sequence III block on inflammatory diseases and asthma. A short review of pertinent pathophysiology is followed by a detailed presentation on the various classes of asthma drugs which includes their chemistry, mechanism of action, pharmacokinetics, toxicity, and interactions. This presentation is designed to prepare students for asthma therapeutics, which follows next in the schedule. The complexities of asthma pharmacotherapy are stressed along with current controversies and future drug development.

Cost-effectiveness of omalizumab in adults with severe asthma: results from the Asthma Policy Model

BACKGROUND

Omalizumab (trade name Xolair) is approved by the US Food and Drug Administration for treatment of moderate-to-severe allergic asthma. Given the high acquisition cost of omalizumab, its role and cost-effectiveness in disease management require definition.

OBJECTIVE

We sought to identify the clinical and economic circumstances under which omalizumab might or might not be a cost-effective option by using a mathematic model.

METHODS

We merged published data on clinical and economic outcomes (including acute event incidence, frequency/severity of hospitalizations, and health-related quality of life) to project 10-year costs, quality-adjusted life years (QALYs), and cost-effectiveness of treatment with omalizumab in addition to inhaled corticosteroids. Sensitivity analyses were conducted by using input data ranges from a variety of sources (published clinical trials and observational databases).

RESULTS

For patients with baseline acute event rates, omalizumab conferred an additional 1.7 quality-adjusted months at an incremental cost of $131,000 over a 10-year planning horizon, implying a cost-effectiveness ratio of $821,000 per QALY gained. For patients with 5 times the baseline acute event rate, the cost-effectiveness ratio was $491,000 per QALY gained. The projected cost-effectiveness ratio could fall within a range of other programs that are widely considered to be cost-effective if the cost of omalizumab decreases to less than $200.

CONCLUSION

Omalizumab is not cost-effective for most patients with severe asthma. The projected cost-effectiveness ratios could fall within a favorable range if the cost of omalizumab decreases significantly.

CLINICAL IMPLICATIONS

Based on the high cost of omalizumab, it is especially important that clinicians explore alternative medications for asthma before initiating omalizumab.

Omalizumab reverses the phenotypic and functional effects of IgE-enhanced Fc epsilonRI on human skin mast cells

The dramatic effects of the anti-IgE mAb omalizumab to lower free IgE levels and Fc epsilonRI levels on basophils contrast with more modest clinical effects. Accordingly, whether IgE modulates Fc epsilonRI levels and Fc epsilonRI-dependent mediator release in vitro on human skin mast cells (MC(TC) type) that had matured in vivo is of interest. IgE reversibly enhanced Fc epsilonRI levels on MC(TC) cells in a dose- and time-dependent manner (up-regulation t(1/2) of 4-5 days with 1-3 microg/ml IgE), without affecting cell proliferation. A molar ratio of omalizumab to IgE of 0.9 at baseline prevented receptor up-regulation by 50%, whereas adding omalizumab to MC(TC) cells already with IgE-enhanced Fc epsilonRI levels at molar ratios of 5, 12.5, and 31 reduced Fc epsilonRI levels to baseline with respective t(1/2) values of 8.7, 6.3, and 4.8 days. MC(TC) cells with IgE-enhanced Fc epsilonRI levels were more sensitive to stimulation with a low dose of anti-Fc epsilonRI mAb in terms of degranulation and production of PGD(2), GM-CSF, IL-6, IL-13, and TNF-alpha. Reducing up-regulated Fc epsilonRI levels with omalizumab also reduced mediator release to a low dose of anti-Fc epsilonRI mAb to baseline by 3-4 wk. Thus, reducing free IgE should decrease the hypersensitivity of allergic individuals to low naturally occurring concentrations of allergens.

Omalizumab (Xolair) in children with seasonal allergic rhinitis: leukotriene release as a potential in vitro parameter to monitor therapeutic effects

To investigate the effect of omalizumab, a humanized monoclonal antibody, in addition to specific immunotherapy (SIT) on in vitro sulfidoleukotriene release (SLT) (A) before, (B) directly after, and (C) 1 yr after treatment with omalizumab. Children and adolescents (6.3-17.6 yr) with sensitization to birch and grass pollens and suffering from seasonal allergic rhinitis were included in a Phase III, placebo-controlled, multicenter clinical study. Within the four-arm study, patients were randomly chosen to receive SIT for either birch or grass pollen and either subcutaneous omalizumab or placebo for 24 wk during the pollen season. Thereafter, omalizumab or placebo treatment ended, but SIT therapy continued. Blood samples were collected from 92 (A, B) and 78 children (C), respectively. Leukocytes were isolated and stimulated with grass and birch pollen allergens. In the supernatants, SLT (LTC4, LTD4, LTE4) were measured using ELISA [cellular allergen stimulation test, DPC-Biermann, Germany]. At the end of treatment the combination of omalizumab + SIT-grass [median SLT-release: 2125 (before) and 416 ng/ml (after omalizumab treatment); p < 0.001] as well as omalizumab + SIT-birch [1404 and 207 ng/ml; p < 0.001] resulted in significantly lower SLT release after stimulation with the corresponding allergen compared to placebo + SIT-grass [2231 and 2490 ng/ml] or placebo + SIT-birch [1324 and 2489 ng/ml]. One year after omalizumab or placebo treatment, there was no significant difference in SLT release between the 4 groups (omalizumab + SIT-grass: 2855; SIT-grass + placebo: 2543; omalizumab + SIT-birch: 2417; SIT-birch + placebo: 2573 ng/ml). These results strongly suggest that the observed effects of decreased SLT release after omalizumab treatment were attributable to the treatment with omalizumab, rather than to SIT therapy.

Anti-immunoglobulin E therapy with omalizumab for asthma

OBJECTIVE

To evaluate data on anti-immunoglobulin E (anti-IgE) therapy for asthma.

DATA SOURCES

Information was selected from PubMed from 1989 to May 2007 using the search term omalizumab and included randomized, controlled trials. These studies evaluated asthma treatment with omalizumab and focused on its efficacy, tolerability, and cost-effectiveness in this population.

STUDY SELECTION AND DATA EXTRACTION

All randomized clinical trials were reviewed (23 were identified and 19 were included; 3 were not relevant and 1 contained duplicative data). Other articles using the search words anti-IgE therapy and cost-effectiveness were evaluated; relevant information was extracted.

DATA SYNTHESIS

IgE-dependent mechanisms play an important role in the development and maintenance of airway inflammation in asthma. Omalizumab is a subcutaneously administered monoclonal anti-IgE antibody that reduces unbound IgE concentrations and promotes down-regulation of IgE receptors. Results from clinical trials in adults, adolescents, and children with poorly controlled IgE-mediated asthma have shown that omalizumab improves symptom control and allows patients to be managed with lower doses of inhaled corticosteroids (ICS). It has been well tolerated in clinical trials lasting as long as 52 weeks, but injection-site reactions are common (45% in omalizumab group vs 43% in placebo group) and anaphylaxis has occurred in 0.2% of patients. A consensus expert panel has recommended that omalizumab should be considered for patients 12 years of age or older with allergic asthma who are inadequately controlled on guideline-based therapy and require maintenance therapy with systemic corticosteroids or high-dose ICSs, or who have poor adherence to ICS therapy.

CONCLUSIONS

Anti-IgE therapy provides an effective and generally safe approach to the treatment of patients with IgE-mediated asthma who are not adequately controlled by conventional guideline-based medications. However, the potential benefit must be weighed against the cost and inconvenience of this new therapy.

Safety of anti-immunoglobulin E therapy with omalizumab in allergic patients at risk of geohelminth infection

Background

Although the role of immunoglobulin E (IgE) in immunity against helminth parasites is unclear, there is concern that therapeutic antibodies that neutralize IgE (anti-IgE) may be unsafe in subjects at risk of helminth infection.

Objective

We conducted an exploratory study to investigate the safety of omalizumab (anti-IgE) in subjects with allergic asthma and/or perennial allergic rhinitis at high risk of intestinal helminth infection. The primary safety outcome was risk of infections with intestinal helminths during anti-IgE therapy.

Methods

A randomized, double-blind, placebo-controlled trial was conducted in 137 subjects (12–30 years) at high risk of geohelminth infection. All subjects received pre-study anthelmintic treatment, followed by 52 weeks' treatment with omalizumab or placebo.

Results

Of the omalizumab subjects 50% (34/68) experienced at least one intestinal geohelminth infection compared with 41% (28/69) of placebo subjects [odds ratio (OR) 1.47, 95% confidence interval (CI) 0.74–2.95, one-sided P = 0.14; OR (adjusted for study visit, baseline infection status, gender and age) 2.2 (0.94–5.15); one-sided P = 0.035], providing some evidence for a potential increased incidence of geohelminth infection in subjects receiving omalizumab. Omalizumab therapy was well tolerated, and did not appear to be associated with increased morbidity attributable to intestinal helminths as assessed by clinical and laboratory adverse events, maximal helminth infection intensities and additional anthelmintic requirements. Time to first infection (OR 1.30, 95% CI 0.79–2.15, one-sided P = 0.15) was similar between treatment groups. Infection severity and response to anthelmintics appeared to be unaffected by omalizumab therapy.

Conclusions

In this exploratory study of allergic subjects at high risk of helminth infections, omalizumab therapy appeared to be safe and well tolerated, but may be associated with a modest increase in the incidence of geohelminth infection.

Targeted therapy for allergic asthma: predicting and evaluating response to omalizumab

Evaluation of: Bousquet J, Rabe K, Humbert M et al. Predicting and evaluating response to omalizumab in patients with severe allergic asthma. Respir. Med. 101(7), 1483-1492 (2007). Among new asthma therapies, omalizumab is the only monoclonal antibody that has been proven to be effective and safe in treating severe, inadequately controlled asthma. Nevertheless, it has been pointed out that not all patients respond to it. This paper analyzes the results of a recent study that was aimed at achieving a more accurate evaluation of the response to omalizumab in patients with severe allergic asthma, by identifying possible pretreatment characteristics that can be predictive of a better and superior response to omalizumab. The results established that it is difficult to predict which patients will gain most benefit from treatment, according to pretreatment baseline characteristics.

Predicting and evaluating response to omalizumab in patients with severe allergic asthma

BACKGROUND

Omalizumab is a monoclonal antibody indicated for treatment of severe persistent allergic asthma inadequately controlled despite optimal controller therapy. We investigated whether patient selection could be targeted further.

METHODS

Data from seven randomized controlled omalizumab trials were analyzed to investigate whether pre-treatment patient baseline clinical characteristics could be identified that were predictive of a superior response to omalizumab. We also studied whether patients who respond to omalizumab following a course of treatment could be reliably identified. Univariate/multivariate analyses of INNOVATE data were performed to identify predictive baseline measures and further investigated in efficacy analyses of pooled data from seven studies. The best method of identifying responders to omalizumab following treatment was determined by assessing the ability of various clinical response criteria to identify responders and discriminate patient exacerbation and other outcomes.

RESULTS

Baseline total immunoglobulin E (IgE) was the only predictor of efficacy in INNOVATE. However, pooled analysis showed treatment benefits irrespective of IgE levels. In omalizumab-treated patients, physician's overall assessment following a course of treatment identified 61% as responders and best discriminated treatment outcomes.

CONCLUSION

Baseline characteristics do not reliably predict benefit with omalizumab. Physician's overall assessment after 16 weeks of treatment is the most meaningful measure of response to therapy.

New developments in FcepsilonRI regulation, function and inhibition

The high-affinity Fc receptor for IgE (FcepsilonRI), a multimeric immune receptor, is a crucial structure for IgE-mediated allergic reactions. In recent years, advances have been made in several important areas of the study of FcepsilonRI. The first area relates to FcepsilonRI-mediated biological responses that are antigen independent. The second area encompasses the biological relevance of the distinct signalling pathways that are activated by FcepsilonRI; and the third area relates to the accumulated evidence for the tight control of FcepsilonRI signalling through a broad array of inhibitory mechanisms, which are being developed into promising therapeutic approaches.

Anti-IgE antibodies for the treatment of IgE-mediated allergic diseases

The pharmacological purposes of the anti-IgE therapy are to neutralize IgE and to inhibit its production to attenuate type I hypersensitivity reactions. The therapy is based on humanized IgG1 antibodies that bind to free IgE and to membrane-bound IgE on B cells, but not to IgE bound by the high-affinity IgE.Fc receptors on basophils and mast cells or by the low-affinity IgE.Fc receptors on B cells. After nearly 20 years since inception, therapeutic anti-IgE antibodies (anti-IgE) have been studied in about 30 Phase II and III clinical trials in many allergy indications, and a lead antibody, omalizumab, has been approved for treating patients (12 years and older) with moderate-to-severe allergic asthma. Anti-IgE has confirmed the roles of IgE in the pathogenesis of asthma and helped define the concept "allergic asthma" in clinical practice. It has been shown to be safe and efficacious in treating pediatric allergic asthma and treating allergic rhinitis and is being investigated for treating peanut allergy, atopic dermatitis, latex allergy, and others. It has potential for use to combine with specific and rush immunotherapy for increased safety and efficacy. Anti-IgE thus appears to provide a prophylactic and therapeutic option for moderate to severe cases of many allergic diseases and conditions in which IgE plays a significant role. This chapter reviews the evolution of the anti-IgE concept and the clinical studies of anti-IgE on various disease indications, and presents a comprehensive analysis on the multiple intricate immunoregulatory pharmacological effects of anti-IgE. Finally, it reviews other approaches that target IgE or IgE-expressing B cells.

Asthma treatment: 'magic bullets which seek their own targets'

The most fascinating options of the new asthma treatments are probably represented by monoclonal antibodies. In fact, these molecules are virtually able to interact with whatever specific antigen. Anyway, it is mandatory to understand the limits of this group of molecules, in terms of both efficacy and safety. In this review, we have analyzed different ways of interfering along the course of the cascade of the allergic reaction, targeting different molecules (CD4, TNF-alpha, IL-4, IL-5, IL-10, IL-12, endothelial adhesion molecules, IgE), showing the efficacy and the risks of each kind of treatment. In the end, we focused our attention on omalizumab, the monoclonal antibody targeting IgE. Although with some restrictions, represented by the high costs and the limitation of its use only to a specific subset of patients affected by allergic asthma, at present anti-IgE appear to be the only 'magic bullet' for the treatment of allergic asthma. In fact, it proved to reduce exacerbations and symptom scores, and to improve quality of life, with a very good safety profile.

New perspectives in the treatment of allergic rhinitis and asthma in children

PURPOSE OF REVIEW

Allergic rhinitis and asthma are some of the most prevalent chronic diseases in children. Meticulous evaluations of the therapeutic options and interventions are needed to control this burden. The central pathogenic mechanism is an immediate hypersensitivity reaction, followed by interventions in the allergic cascade. Once inflammation is established, potent anti-inflammatory agents or mediator antagonists could help control the phenomenon and reduce the characteristic symptoms related to severity.

RECENT FINDINGS

Monoclonal antibody against IgE has demonstrated its efficacy in reducing the symptoms of asthma and rhinitis. In difficult-to-treat asthma patients it allows a reduction in the dose of inhaled steroids, the number of exacerbations, emergency visits and hospitalizations. Its broad implementation is limited by its high cost because adverse events are not a concern. Specific sublingual immunotherapy gave promising results in clinical trials, while modifying immunoglobulins and cytokine profiles, also inducing T-cell tolerance. Safety issues of subcutaneous immunotherapy have been surpassed by the sublingual route, with equivalent efficacy. The new inhaled steroid ciclesonide is effective in established inflammation, is activated only in the respiratory system, and has negligible systemic effects.

SUMMARY

Robust evidence on the efficacy and safety of several novel therapies in rhinitis and asthma is available.

The impact of comorbid atopic disease on asthma: clinical expression and treatment

Clinically, asthma and allergic rhinitis involve separate regions of the respiratory tract while representing a common underlying inflammatory syndrome. Much evidence supports an epidemiologic association between the diseases, paranasal sinus involvement in both conditions, and parallel relationship in severity and treatment outcomes. Pathophysiologic mechanisms, including immunoglobulin E (IgE)- mediated inflammation, are also shared. Blocking IgE with the recombinant humanized monoclonal antibody omalizumab demonstrated clinical efficacy in patients with upper and lower airway diseases. IgE blockade, leukotriene modulation, and B-cell depletion therapy have all exhibited success in chronic inflammation, reinforcing and expanding the beneficial role of immunomodulation of global mediators.

Association between IgE levels and asthma severity among African American, Mexican, and Puerto Rican patients with asthma

BACKGROUND

High levels of IgE are associated with asthma. Whether higher levels of IgE are associated with more severe asthma is still unclear.

OBJECTIVE

To determine whether IgE is associated with asthma severity among Latino and African American subjects with asthma.

METHODS

We assessed lung function and asthma severity among African American, Mexican, and Puerto Rican patients with asthma with high IgE levels (> or =100 IU/mL; n = 492) and compared these values to those of patients with asthma with low IgE levels (<100 IU/mL; n = 247). We also examined IgE as a continuous variable among these groups.

RESULTS

Patients with asthma with high IgE had a lower mean FEV(1) (87.6 +/- 17.1, percent of predicted) than patients with asthma with low IgE (91.5 +/- 17.0; P = .031). Regardless of race and ethnicity, baseline FEV(1), forced expiratory flow, and FEV(1)/forced vital capacity were lower among subjects with high IgE than among subjects with low IgE (P = .031, P < .0001, P = .0001, respectively). In addition, 54.7% of patients with asthma with high IgE had been previously hospitalized, compared with 44.1% of patients with asthma with low IgE (odds ratio, 1.33; 95% CI, 1.04-1.71).

CONCLUSION

Higher IgE is associated with lower baseline lung function and more severe asthma among these populations.

CLINICAL IMPLICATIONS

Among patients with asthma from 3 ethnically distinct groups, total IgE levels are inversely correlated with baseline lung function and asthma severity.

Severe asthma in adults: what are the important questions?

The term severe refractory asthma (SRA) in adults applies to patients who remain difficult to control despite extensive re-evaluation of diagnosis and management following an observational period of at least 6 months by a specialist. Factors that influence asthma control should be recognized and adequately addressed prior to confirming the diagnosis of SRA. This report presents statements according to the literature defining SRA in order address the important questions. Phenotyping SRA will improve our understanding of mechanisms, natural history, and prognosis. Female gender, obesity, and smoking are associated with SRA. Atopy is less frequent in SRA, but occupational sensitizers are common inducers of new-onset SRA. Viruses contribute to severe exacerbations and can persist in the airways for long periods. Inflammatory cells are in the airways of the majority of patients with SRA and persist despite steroid therapy. The T(H)2 immune process alone is inadequate to explain SRA. Reduced responsiveness to corticosteroids is common, and epithelial cell and smooth muscle abnormalities are found, contributing to airway narrowing. Large and small airway wall thickening is observed, but parenchymal abnormalities may influence airway limitation. Inhaled corticosteroids and bronchodilators are the mainstay of treatment, but patients with SRA remain uncontrolled, indicating a need for new therapies.

Anti-IgE and chemotherapy: a critical appraisal of treatment options for severe asthma

In this narrative review the scientific rationale for the development of a therapeutic modality for asthma based on decreasing the circulating and cell-bound levels of immunoglobulin-E (IgE) is outlined. The one drug that has so far entered clinical practice to do this is a humanised monoclonal antibody to the Fc portion of the IgE molecule, omalizumab. It is highly effective in reducing IgE blood levels and its established mode of delivery is by subcutaneous injection. The clinical trial development of omalizumab is reviewed and the published data and claims for its efficacy and role in clinical practice is critically appraised. The target group of omalizumab has become focused on severe asthmatics who are still symptomatic after being administered with high-dose inhaled corticosteroids plus long-acting beta-agonists. The strongest evidence for effect is in those with frequent severe exacerbations.