Omalizumab improves asthma-related quality of life in patients with severe allergic asthma

Omalizumab: Practical considerations regarding the risk of anaphylaxis

Omalizumab has demonstrated efficacy among patients with moderate to severe persistent allergic asthma, whose symptoms are inadequately controlled with other controller agents. This therapy is generally well tolerated, but there are some safety considerations, the most important of which is the rare, but potentially life-threatening, occurrence of omalizumab-associated anaphylaxis.In Canada, data from the manufacturer of omalizumab indicate that the frequency of anaphylaxis attributed to Xolair in post-marketing use is approximately 0.2%. Other researchers, including the American Omalizumab Joint Task Force (OJTF), have suggested a lower overall frequency of 0.09%.This paper provides a summary of the epidemiologic research carried out to date and presents a concise, practical set of recommendations for the prevention, monitoring and management of omalizumab-associated anaphylaxis. Prevention tips include advice on patient education measures, concomitant medications and optimal administration. For the first three injections, the recommendation is to monitor in clinic for two hours after the omalizumab injection; for subsequent injections, the monitoring period should be 30 minutes or an appropriate time agreed upon by the individual patient and healthcare professional.In the event that a patient does experience omalizumab-associated anaphylaxis, the paper provides recommendations for handling the situation in-clinic and recommendations on how to counsel patients to recognize the potential signs and symptoms in the community and react appropriately.

Recommendation for optimal management of severe refractory asthma

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

Use of biologicals as immunotherapy in asthma and related diseases

Recent advances in our understanding of the immune-mediated inflammatory pathways in asthma and other allergic diseases have resulted in the development of novel biological compounds for the treatment of these conditions. These compounds offer an advantage over glucocorticosteroid therapy by specifically targeting components of the immunologic cascade, thereby allowing patients to reduce or discontinue their glucocorticosteroid treatment. Another potential advantage of biological compounds is that they may provide additional anti-inflammatory benefits, over and above those provided by glucocorticosteroid therapy, for patients who continue to have evidence of refractory asthma. The anti-IgE monoclonal antibody omalizumab is already being used for the treatment of allergic asthma and a number of other biological therapies are currently in various stages of clinical development. The purpose of this review is to summarize the data from these studies and to provide a rationale for the use of these compounds in asthma and related allergic airway diseases.

Reduced FcepsilonRI-mediated release of asthma-promoting cytokines and chemokines from human basophils during omalizumab therapy

BACKGROUND

Treating asthmatics with the humanized IgE-scavenging antibody, omalizumab (rhuMAb-E25, Xolair, reduces airways inflammation and asthma symptoms. Previously, omalizumab was shown to cause a dramatic and reversible loss of cell surface high-affinity IgE receptors, FcepsilonRI, from the peripheral blood basophils of asthmatics. The consequences of receptor loss for the FcepsilonRI-mediated synthesis and release of cytokines implicated in allergic asthma have not been examined.

METHODS

Fifteen asthmatic volunteers each received omalizumab for 12 weeks. Peripheral blood basophils were isolated before, during, 2 weeks after and 6 months after omalizumab. Basophils were assayed for the basal and anti-IgE-stimulated release of cytokines, chemokines and histamine. Pooled data were analyzed by repeated measures ANOVA and by paired t tests.

RESULTS

Anti-IgE-stimulated human basophils synthesize and release Th2 cytokines (IL-4, IL-13) and chemokines (IL-8, RANTES). The anti-IgE-stimulated release of IL-4, IL-13 and IL-8 was reduced during omalizumab treatment and returned to pretreatment levels after omalizumab withdrawal. Omalizumab did not alter basophil histamine levels or basal and anti-IgE-stimulated histamine release.

CONCLUSIONS

Omalizumab may reduce asthma symptoms in part by suppressing the FcepsilonRI-mediated production by basophils of Th2 cytokines and selected chemokines. Anti-IgE-stimulated basophil cytokine synthesis appears more sensitive than histamine release to the loss of FcepsilonRI caused by omalizumab treatment.

[Analysis of asthma control and quality of life in severe allergic asthmatics under treatment with anti-IgE, omalizumab]

BACKGROUND AND OBJECTIVES

To evaluate anti-IgE (ie, omalizumab) efficacy on severe allergic asthma in order to achieve the efficacy of this treatment on severe allergic asthma progress by means of asthma control questionnaire (ACQ), asthma quality of life questionnaire (AQLQ) as well as pulmonary function (FEV1) and physician overall assessment.

PATIENTS AND METHODS

Fourteen patients were studied who suffered from severe allergic asthma for several years; average 20.7yr. A positive skin prick test or specific IgE antibodies to a common aeroallergen were observed in all patients who were under treatment with high doses of inhaled corticosteroids (eight of them also with oral corticosteroids). Omalizumab 150-600 mg were administrated once or twice monthly and each patient was monthly evaluated until sixteen weeks, deciding at this time which patient was or not responder in order to follow up or not omalizumab treatment.

RESULTS

Physician overall assessment improved in 11 out of every 14 patients. A marked improvement was observed at two months in ACQ and AQLQ (p<0.05) and at 3 and 4 moths only in AQLQ and AQLQ-symptoms respectively (p<0.05). The FEV1 improved by 9.4% average (p=0.24). Oral corticosteroids were reduced in 4 of 8 patients and in another one there was a definitive suspension. Two patients suffered adverse reactions which suspension of treatment despite the fact that they presented improvement in questionnaires of quality of life and control of asthma.

CONCLUSIONS

Omalizumab showed a marked global efficacy in more than 3 out of 4 patients suffering severe allergic asthma as revealed by physician overall assessment. Moreover significant improvements were observed in ACQ; AQLQ; AQLQ-symptoms at 2, 3 and 4 months of treatment, without significant changes in FEV1 probably due to chronic irreversible changes in airways.

Immunomodulatory and biologic therapies for severe refractory asthma

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

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.

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.

Response of older patients with IgE-mediated asthma to omalizumab: a pooled analysis

Asthma in older adults is under-recognized and possibly associated with allergic triggers. We conducted a pooled analysis of omalizumab double-blind, placebo-controlled trials to evaluate efficacy in older adults. Data for the total study population and subjects aged > or = 50 years with moderate-severe allergic asthma were examined. We used Poisson regression to analyze the number of asthma exacerbations and logistic regression to evaluate treatment effectiveness. Symptom scores and total rescue medication puffs were evaluated by analysis of covariance. Omalizumab reduced the risk of clinically significant asthma exacerbations, led to a significantly greater response in patient/investigator-reported global effectiveness, improved asthma symptom scores, and reduced rescue medication use in adults > or = 50 years with moderate-severe allergic asthma.

Omalizumab (Xolair) in patients with steroid-resistant asthma: lessons to be learnt

Very severe asthma and local pulmonary steroid resistance causes major problems for patients, physicians and the health system at large. It usually results in multiple admissions to hospital and high morbidity. Omalizumab was used to treat such patients with success. However, in doing so, it raised a number of issues relating to the best methods of using this treatment in such patients.

[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.

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.

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.

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).

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.

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.

Basophils are essential initiators of a novel type of chronic allergic inflammation

Basophils represent less than 1% of peripheral blood leukocytes and have often been considered as minor and possibly redundant circulating mast cells. The recent finding that basophils readily generate large quantities of T helper 2 (Th2) cytokines such as IL-4 provided new insights into the possible role of basophils in allergic disorders and immunity to pathogens. However, in-depth studies on basophils, particularly their functions in vivo, have been hampered by the lack of appropriate animal models, such as mutant animals deficient only in basophils. Here, we established a mAb that reacted with mouse basophils and depleted them when administered in vivo. The mAb treatment of mice did not show any significant effect on classical allergic reactions such as passive cutaneous anaphylaxis and contact hypersensitivity. In contrast, it completely abolished the development of IgE-mediated chronic allergic dermatitis that is characterized by massive eosinophil infiltration, even though basophils accounted for only approximately 2% of the infiltrates. The treatment during the progression of the dermatitis resulted in drastic reduction in numbers of infiltrating eosinophils and neutrophils, concomitantly with elimination of basophils from the skin lesions. Thus, basophils play a pivotal role in the development of IgE-mediated chronic allergic inflammation, as an initiator rather than as an effector.

Omalizumab decreases nonspecific airway hyperresponsiveness in vitro

BACKGROUND

In asthmatic patients, both symptoms and hyperresponsiveness are related to immunoglobulin E (IgE) concentration in serum. The anti-IgE monoclonal antibody omalizumab improved the control of asthma, but its effect on airway hyperresponsiveness is controversial. Passive sensitization reproduced in vitro a bronchial hyperresponsiveness, an increase in IgE bearing cells, and a mast cell degranulation. This study was designed to examine the effect of omalizumab on passive sensitization-induced hyperresponsiveness, alterations in IgE positive inflammatory cells and mast cell degranulation within the bronchial wall.

METHODS

Proximal (3-5 mm diameter) and distal (0.5-1.5 mm diameter) human bronchi dissected out from 10 lung specimens were incubated in normal or asthmatic serum containing various concentrations of omalizumab. Contractile responses to histamine or Dermatophagoides pteronyssinus (D. pter) were recorded using an organ bath system and expressed as percentage of maximal contractile response to acetylcholine (ACh). Immunohistochemistry was performed using monoclonal antibodies directed against IgE or tryptase. Mast cells were classified as fully granulated (type I), partly (type II) or largely degranulated (type III).

RESULTS

The specific bronchial hyperresponsiveness to D. pter and the nonspecific bronchial hyperresponsiveness to histamine following passive sensitization were significantly inhibited by omalizumab in both distal and proximal airways. Passive sensitization-induced increase in IgE positive cells was also abolished by omalizumab in a concentration dependent manner. Mast cell degranulation which was inhibited by omalizumab was positively correlated with the contractile response to D. pter.

CONCLUSIONS

Omalizumab blocks specific and nonspecific bronchial hyperresponsiveness. Anti-IgE also decreases IgE bearing cell number and mast cell degranulation.

Promise and pitfalls in animal-based asthma research: building a better mousetrap

Asthma is one of the leading chronic diseases in the world today. An essential component of the asthma research endeavor is the animal-based experimental disease system, which provides knowledge that is not attainable through study of patients alone. Animal research is especially valuable for elucidating pathophysiology, drug testing, and as an adjunct for interpreting the results of human clinical trials. However, controversies surrounding animal systems data and at the interface between animal and human studies raise questions regarding the true utility of experimental asthma research. We consider here the considerable promise and important limitations of animal-based systems and their prospects for the future study asthma.

Autologous serum skin test for autoantibodies is associated with airway hyperresponsiveness in patients with asthma

BACKGROUND

Autoimmune diseases have been implicated as a cause of intrinsic asthma; however, there is little data on the role of autoimmunity in the pathogenesis of asthma.

OBJECTIVE

The purpose of this study was to investigate circulating functional autoantibodies against the high-affinity IgE receptor FcepsilonRI or IgE in patients with asthma.

METHODS

Twenty-eight patients with asthma and 19 control subjects were included. All subjects were skin tested with autologous serum to assess for the potential presence of receptor FcepsilonRI or IgE autoantibodies. If the serum-induced wheal diameter was 1.5 mm larger than the histamine-induced wheal diameter and that was 3 mm larger than the saline-induced wheal diameter at 30 min, the reaction was defined positive.

RESULTS

Of the 47 total subjects (both asthma patients and control subjects), 13 (27.7%) had a positive autologous serum skin test (ASST). Of the 28 asthma patients, 8 (28.6%) were regarded as having autoimmune origin. Autoantibodies against FcepsilonRI or IgE were found in asthma patients, irrespective of atopic status (atopy+ 3/13 vs. atopy- 5/15). The wheal diameter related to ASST was not related to atopy. Asthma patients with ASST-positive results as compared with patients with ASST-negative results exhibited a significant increased airway hyperresponsiveness (PC(20) methacholine, 2.70 +/- 1.27 vs. 9.08 +/- 2.35; p < 0.026).

CONCLUSION

Our data demonstrate that aberrant autoantibodies against the high-affinity IgE receptor FcepsilonRI or IgE are related to airway hyperresponsiveness in patients with asthma.

The economic value of anti-IgE in severe persistent, IgE-mediated (allergic) asthma patients: adaptation of INNOVATE to Sweden

BACKGROUND

Severe allergic asthma patients may not be controlled even with guideline recommended care, including inhaled corticosteroids, long-acting beta-2 agonists, theophylline, oral steroids and anti-leukotrienes. They experience exacerbations requiring intensive healthcare use and which may be fatal. Omalizumab, a new monoclonal antibody for use in IgE-mediated allergic diseases, reduces exacerbations and daily symptoms in this patient population. The aim of this study is to estimate the cost effectiveness of adding omalizumab to optimized standard therapy (ST) in patients with severe persistent IgE-mediated (allergic) asthma.

METHODS

A Markov model comparing lifelong ST with a treatment period of omalizumab add-on therapy followed by ST, was developed based on efficacy data from the INNOVATE trial (28 weeks, N = 419) and Swedish life table and cost data. This model assumes that patients are at risk of having an exacerbation every 2 weeks and are at risk of dying from a clinically significant severe asthma exacerbation. Patients in a steady-state of having no exacerbations are defined to be in an 'optimized asthma control' state. Resource use data and utilities were obtained from INNOVATE and from a UK observational study. Costs from a societal perspective include estimates for drugs, routine care, exacerbations and costs in added years of life; benefits are expressed in QALYs. The response to omalizumab was evaluated after 16 weeks of trial, and non-responders stopped taking omalizumab for the remaining time.

RESULTS

Total lifetime discounted costs and QALYs on ST were 52,702 euros and 11.60. Omalizumab add-on therapy cost an additional 42,754 euros for 0.76 additional QALYs, resulting in an incremental cost-effectiveness ratio of 56,091 euros. A probabilistic sensitivity analysis indicates that the 95% CI around the ICER is [31,328 euros; 120,552 euros]. One-way analyses indicate that the results are sensitive to the exacerbation-related mortality rate, the time horizon and the discount rates.

CONCLUSIONS

Based on the model and the assumptions used, our results suggest that omalizumab provides cost offsets, improves quality of life and may have an attractive ICER in treating the severe allergic asthma population.

Management of asthma with anti-immunoglobulin E: a review of clinical trials of omalizumab

Immunoglobulin E (IgE) is a key mediator of the inflammatory reactions that are central to the pathogenesis of allergic diseases such as asthma and rhinitis. The recognition of the importance of IgE in allergic disease led to the development of omalizumab, a humanized monoclonal anti-IgE antibody that binds free circulating IgE and prevents the interaction between IgE and high-affinity (FcepsilonRI) and low-affinity (FcepsilonRII) IgE receptors on inflammatory cells. By removing free IgE, omalizumab also markedly downregulates the expression of high-affinity receptors on basophils, mast cells and dendritic cells. Several studies have shown that omalizumab effectively reduces the risk of exacerbations and hospitalization and improves symptom control, lung function and quality of life in patients with severe persistent allergic asthma. Importantly, omalizumab has been shown to be effective in patients with poorly controlled severe persistent allergic asthma, a group of patients with few effective additional treatment options. In addition, omalizumab has been shown to provide effective relief from the symptoms of allergic rhinitis (including patients with concomitant asthma). Patients with uncontrolled severe persistent allergic asthma are a challenging and difficult-to-treat population for whom omalizumab might represent an important new treatment option. In addition, omalizumab may provide a means to address comorbid allergic disease in patients with asthma. Further investigation is also warranted to explore potential applications of omalizumab in occupational asthma.

Understanding the pathophysiology of severe asthma to generate new therapeutic opportunities

Although asthma is defined in terms of reversibility of airflow obstruction, as the disease becomes more severe and chronic, it adopts different characteristics, including a degree of fixed airflow obstruction and corticosteroid refractoriness. Underlying these phenotypes is evidence of airway wall remodeling, which should be distinguished from the increase in smooth muscle linked to airways hyperresponsiveness. Aberrant epithelial-mesenchymal communication leads to a chronic wound scenario, which is characterized by activation of the epithelial-mesenchymal trophic unit, epithelial damage, the laying down of new matrix, and greater involvement of neutrophils in the inflammatory response. In allergic asthmatic patients who remain symptomatic despite high-dose corticosteroid therapy, blockade of IgE with omalizumab confers appreciable clinical benefit. Chronic severe asthma is also accompanied by a marked increase in TNF-alpha production that might contribute to corticosteroid refractoriness. Based on this, TNF blockade with the soluble fusion protein entanercept produces improvement in asthma symptoms, lung function, and quality of life paralleled by a marked reduction in airways hyperresponsiveness. Identification of novel susceptibility genes, such as a disintegrin and metalloprotease 33 (ADAM33), will provide further targets against which to direct novel therapies for asthma, especially at the more severe end of the disease spectrum.

Failure of omalizumab for treatment of severe adult atopic dermatitis

Atopic dermatitis has been associated with elevated levels of IgE. Omalizumab is a monoclonal anti-IgE antibody currently approved for the treatment of asthma. We report the failure of omalizumab to improve atopic dermatitis in 3 patients when administered for 4 months.

Safety and tolerability of omalizumab (Xolair), a recombinant humanized monoclonal anti-IgE antibody

Omalizumab (Xolair) is a humanized monoclonal antibody designed to bind specifically to immunoglobulin (Ig)E. It is indicated in the United States for the treatment of adolescent and adult patients (>or=12 yr) with moderate-to-severe persistent asthma who have a positive skin test or in vitro reactivity to a perennial aeroallergen, and whose symptoms are inadequately controlled with inhaled corticosteroids. Omalizumab was evaluated in an extensive clinical development program that included 12 controlled phase IIB/III clinical trials with more than 5,243 patients who were appropriate for inclusion in the safety analysis (all ages in all controlled studies). In these studies, omalizumab had an adverse event profile comparable to that of the control group (i.e., placebo or standard therapy). Data presented in this article supports omalizumab as a safe and well-tolerated agent for the treatment of IgE-mediated asthma.

Anti-IgE for chronic asthma in adults and children

BACKGROUND

Omalizumab is a recombinant humanised monoclonal antibody directed against immunoglobulin E (anti-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 compared with placebo in patients with allergic asthma

SEARCH STRATEGY

We searched the Cochrane Airways Group Asthma trials register for potentially relevant studies (February 2006).

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

Two 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

Fourteen trials (15 group comparisons) were included in the review, contributing a total of 3143 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 (ICS) consumption compared with placebo (-119 mcg/day (95% CI -154 to -83, three trials)). There were significant increases in the number of participants who were able to reduce ICS by over 50% (odds ratio (OR) 2.50, 95% confidence interval (CI) 2.02 to 3.10 (four trials)); or completely withdraw their daily ICS 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 ICS (OR 0.52, 95%CI 0.41 to 0.65, five trials), or as an ICS tapering agent (OR 0.47, 95% CI 0.37 to 0.60, four trials).

AUTHORS' 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 clinical value of the reduction in steroid consumption has be considered in the light of the high cost of Omalizumab. The impressive placebo 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, and during steroid tapering phases of clinical trials. Omalizumab was generally well tolerated, although there were more injection site reactions with Omalizumab. Patient and physician assessments of the drug were positive. Further assessment in paediatric populations is necessary, as is direct double-dummy comparison with ICS.

Impact of omalizumab on quality-of-life outcomes in patients with moderate-to-severe allergic asthma

BACKGROUND

Moderate-to-severe allergic asthma has a substantial impact on patients' quality of life (QOL). Despite care consistent with treatment guidelines, many patients with moderate-to-severe asthma still experience variability in asthma control, signaling an unmet need within this population. Omalizumab has recently demonstrated clinical efficacy and safety in treating IgE-mediated asthma.

OBJECTIVE

To summarize asthma-related QOL outcomes associated with omalizumab therapy in moderate-to-severe allergic asthma.

METHODS

A systematic review and meta-analysis of asthma-related QOL on data from published clinical trials and unpublished clinical study reports were conducted on omalizumab. The Juniper Asthma Quality of Life Questionnaire (AQLQ) measured asthma-related QOL.

RESULTS

Statistically significant results for asthma-related QOL end points consistently favored omalizumab over placebo. Moderate to large effect sizes in the omalizumab groups were observed across the clinical trials and during study extension phases. A meta-analysis indicated a 1.6- to 2-fold increase in moderate (> or = 1 point) and a 1.8- to 2.1-fold increase in large (> or = 1.5 point) improvements in AQLQ overall scores in the omalizumab-treated group compared with placebo during the steroid-stabilization and steroid-reduction phases of the trials.

CONCLUSIONS

Significant differences and large effect sizes favoring omalizumab were observed despite the control group receiving active, guideline-consistent treatment. The meta-analysis findings demonstrate that omalizumab treatment provides QOL benefits in patients with moderate-to-severe allergic asthma.

Symptom control and improved functioning: the effect of omalizumab on asthma-related quality of life (ARQL)

This investigation evaluated variability in asthma-related quality-of-life (ARQL) outcomes among patients randomized to omalizumab or placebo. Pooled data on the Asthma Quality of Life Questionnaire (AQLQ) from two trials were used (n = 948). Variability in ARQL outcomes was determined by categorizing AQLQ score changes according to minimal clinically important difference (MCID: 0.5 points) and large clinically important difference (LCID: 1.5 points) score changes. A greater proportion of patients achieved improvement in every domain of AQLQ scores during all periods with omalizumab compared with placebo. Omalizumab-treated patients showed greater clinically important improvement in ARQL compared with patients receiving placebo.

Asthma: diagnosis and management

The diagnosis and management of asthma continue to be of critical importance, as recent trends have demonstrated its increasing prevalence, morbidity, and perhaps mortality. Because current treatments for asthma are effective and safe, it is important to diagnose asthma early and to use treatments effectively, particularly those directed toward airway inflammation. The diagnostic measures and array of medications, both those currently available and on the horizon, provide an armamentarium for effective diagnosis, management, and monitoring of asthma. In the coming years, it is expected that additional testing modalities will be available for more precise monitoring of asthma control, and an increased understanding of pharmacogenetics will enable the tailoring of asthma medications to specific patients, providing customized therapy to maximize asthma control.

Better breathing or better living? A qualitative analysis of the impact of asthma medication acquisition on standard of living and quality of life in low-income families of children with asthma

INTRODUCTION

Purchasing children's asthma medications places a burden on low-income families. The objective of this study was to explore how purchasing children's asthma medications influenced household purchasing behavior and quality of life in low-income families with no drug insurance.

METHOD

Seventeen parents residing in the Greater Toronto Area with no drug plan and with household incomes below 45,000 US dollars (twice the U.S. poverty level) participated. Semi-structured interviews were conducted, emphasizing the topics of prescription drugs used and cost versus effectiveness; purchasing behavior and drug administration; effects of medication purchasing on the family; and payment assistance. Transcribed narratives were coded and analyzed thematically.

RESULTS

Annual expenditures for asthma drugs were 300 US dollars to 3000 US dollars. Because asthma management was a high priority, foregone expenditures included paying for other family members' health needs, essentials (clothing, food, better housing), and nonessentials (recreation, vacations) and long-term investments, such as their child's future education and their retirement. Respondents believed quality of life was negatively affected.

DISCUSSION

Not addressing the health concerns of family members, making sacrifices, and modifying investment decisions created sustained anxiety in families of children with asthma. Access to medication benefits would have a positive impact on quality of life. Health care providers can help to ensure that low-income families receive available assistance.

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.

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.

Asthma economics: focusing on therapies that improve costly outcomes

PURPOSE OF REVIEW

In 1998, the economic burden of asthma was estimated to be 12.7 billion dollars. Subsequent research has focused on identifying important outcomes that reflect high resource utilization and finding therapies that improve these outcomes and decrease cost. Recent developments include an update to the National Heart, Lung, and Blood Institute (NHLBI) guidelines, new treatment strategies using combination therapy, and the development of a monoclonal antibody therapy for asthma.

RECENT FINDINGS

Two important costly outcomes are asthma-related hospitalizations and emergency department visits. Asthma-related hospitalizations started to decline in the 1990s, primarily in white Americans, but not in young African Americans. Many hospitalizations and emergency department visits are preventable, and costs were lowered by shifting management to the ambulatory care setting. Increased asthma severity and suboptimal compliance with NHLBI asthma care guidelines can contribute to the persistence of symptoms, which triggers behaviors that increase resource utilization.A recent economic analysis was one of the first well-controlled clinical trials to show that inhaled corticosteroids provide clinical benefit at modest costs. Combination therapy, particularly that containing an inhaled corticosteroid and long-acting bronchodilator in a single inhaler, potentially can reduce overall costs by improving compliance with inhaled corticosteroids. Nonpharmacologic therapies also have been shown to be cost-effective. However, a significant number of patients with asthma continue to have symptoms even while on recommended controller therapy. Omalizumab, a monoclonal antibody treatment that binds IgE, was released in the summer of 2003.

SUMMARY

Many costly asthma-related hospitalizations and emergency department visits are preventable, and chronic disease care can be shifted to the ambulatory setting. Increased asthma severity and noncompliance with NHLBI guidelines are associated with increased resource utilization. Combination therapies can assist in improving patient compliance, and omalizumab potentially offers a novel but expensive way to decrease symptoms and resource utilization.

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.

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.

Intranasal immunisation using recombinant Lactobacillus johnsonii as a new strategy to prevent allergic disease

We have previously demonstrated the induction of a specific anti-IgE response in vivo by parenteral immunisation of rhesus monkeys using short IgE mimotopes or an anti-idiotypic antibody mimicking an IgE epitope. Such specific anti-IgE responses may be of clinical benefit for atopic patients. In this study, we examined the potential for a more convenient therapy via mucosal immunisation using live recombinant Lactobacillus johnsonii (Lj) as a vaccine delivery vehicle. Either an anti-idiotypic scFv or an IgE mimotope were expressed on the surface of Lj as fusion proteins using the cell wall anchored proteinase PrtB from Lactobacillus delbrueckii subsp. bulgaricus. The recombinant Lj were shown to express the heterologous fusion proteins and were specifically recognised by the corresponding anti-human IgE monoclonal antibody. Subcutaneous and intranasal immunisation of mice with recombinant Lj, expressing these fusion proteins induced a systemic IgG response against human IgE. Our data suggest that recombinant Lactobacilli expressing IgE epitopes may represent a novel means of vaccination to induce a beneficial anti-IgE response.