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

Anti-IgE therapy

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

Immunomodulation: the future of allergy and asthma treatment

PURPOSE OF REVIEW

As the prevalence of asthma and allergic disease increases around the world, it is clear that more effective therapies and disease-modifying agents are needed. Treatment for allergic disease is evolving with an increase in understanding of the etiology.

RECENT FINDINGS

The first immunomodulatory treatment was recently approved for use in the United States when the Food and Drug Administration approved the use of a humanized monoclonal anti-IgE antibody in patients with allergic asthma. Another strategy that has proved effective in a murine model is the downregulation of the whole immune system by targeting adhesion molecules, which has been evaluated in a recent human trial. Other strategies for the treatment of allergic diseases concentrate on refocusing the immune system away from an allergic-type response. These include the use of targeted therapies towards specific cytokines, cytokine receptors or chemokine receptors, and the use of specific bacterial DNA sequences (unmethylated cytosine-guanine dinucleotides). Finally, attention is being focused on possible therapies that may tilt the immune response to a non-allergic response by interfering with signaling molecule pathways.

SUMMARY

Immunomodulation will play a key role in future therapies for allergic disease. These treatment modalities may not only treat allergic disease, but also be beneficial in reducing the morbidity and mortality for which it is responsible.

Rationale for new treatments aimed at IgE immunomodulation

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTION

Key articles were selected by the authors.

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Omalizumab: a novel therapy for allergic asthma

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTION AND DATA EXTRACTION

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

DATA SYNTHESIS

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

CONCLUSIONS

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

Current concepts in asthma treatment in children

PURPOSE OF REVIEW

The purpose of this review is to present current literature related to the management of childhood asthma.

RECENT FINDINGS

Persistent asthma is now considered an inflammatory airways disease. Inhaled corticosteroids are recognized as the preferred long-term control medication. New classes of medications have been introduced during the last 5 years, including leukotriene modifiers, long-acting beta-adrenergic agonists, combination inhaled corticosteroids with long-acting beta-adrenergic agonists, and anti-IgE. Research is also being directed to understand the early onset of asthma.

SUMMARY

Management of childhood asthma is now being directed to early recognition and early intervention. Recent updates in the asthma guidelines prompt clinicians to consider intervention with antiinflammatory therapy, preferably inhaled corticosteroids, in children who have frequent asthma exacerbations and a risk profile for persistent asthma. In children with persistent asthma, inhaled corticosteroids are recognized as the preferred antiinflammatory therapy. Health care systems that have adapted this approach have recognized the benefits of reduced hospitalizations and urgent care visits. Continued research is needed to identify asthma at a very early stage so that interventions can be directed to interrupting the development of this disease.

Clinical implications of the allergic rhinitis-asthma link

A possible link between allergic rhinitis (AR) and allergic asthma has long been a subject of debate. Surveys report that up to 78% of asthma patients have AR and 38% of patients with AR have asthma. Evidence points to a causal or coincidental relation between these upper and lower airway diseases. Various agents used to manage one entity have shown benefit in treating the other. The 2001 Allergic Rhinitis and Its Impact on Asthma guidelines call for patients with either condition to be assessed for the other. Medical therapy for AR or asthma should be chosen with awareness of the probable coexistence of these diseases. We present the case for and against the united airway theory proposed to explain the association between these diseases. The roles of various therapies for dually afflicted patients are evaluated, including topical corticosteroids, antihistamines, leukotriene modifiers, anti-immunoglobulin E monoclonal antibody, theophylline, and immunotherapy.

Advances in adult and pediatric asthma

This review summarizes the highlights in the study of adult and pediatric asthma from October 2002 through October 2003. It is easiest to categorize this year's advances into physiologic, epidemiologic, therapeutic, and primarily pediatric developments. In physiology the identification of the ADAM33 gene as an asthma susceptibility gene has led to a new hypothesis concerning the pathogenesis of asthma. Understanding the integration of the upper and lower airways is likely to have important implications for patient management. Epidemiologic studies continue to show that asthma is a significant and costly disease, with medications comprising the most significant direct costs. Early intervention and improved management can significantly reduce the burden of illness. Research presented indicates there is an opportunity for allergist-immunologists to improve diagnostic and therapeutic approaches to asthma management. Our community has a strong commitment to health care quality, education, and delivery. The Journal will reflect this commitment with a new section devoted to these issues.

The office management of recalcitrant rhinosinusitis

The patient referred to the otolaryngologist for the treatment of CRS has received many therapies for the condition. Newer therapies available focus on the anti-inflammatory therapies and local application of antimicrobial and antifungal agents to the sinus cavities. Much clinical work remains to be done to prove the efficacy of currently available treatments. The recent advances in the understanding of allergic and immune mechanisms may allow eventual intervention at the level of cytokines and other immunomodulators of inflammation. The complex cascade of interleukins and proinflammatory agents in CRS patients may some day allow "silver bullet" therapies in the properly selected patient. Until then, a systematic approach to the evaluation of these patients and management with the currently available treatment modalities may help relieve the symptoms in patients with CRS.

Anti-IgE for chronic asthma in adults and children

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

REVIEWERS' CONCLUSIONS

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

Atopic diseases of childhood

PURPOSE OF REVIEW

The incidence of atopic diseases, including atopic dermatitis, allergic rhinitis, and asthma, has increased in developed countries over the past several decades. These diseases comprise a large component of general pediatric practice. This review will highlight some of the recent advances in understanding the pathogenesis and natural history of these diseases, as well as the current approaches to the treatment of children with atopic diseases.

RECENT FINDINGS

Recent studies have identified multiple risk factors for the development and progression of atopic diseases. As a result, much research is focused on identifying therapies that can be initiated at a young age to prevent disease progression. New treatment options have become available in recent years, such as topical immunomodulators for atopic dermatitis, leukotriene antagonists for seasonal allergic rhinitis, and alpha-immunoglobulin E therapy for asthma. The importance of viewing allergic rhinitis and asthma as disorders of a single airway has been emphasized. Finally, an update on the national asthma guidelines was recently released in an effort to promote optimal asthma care.

SUMMARY

This review summarizes many of the recent advances in the diagnosis and treatment of atopic diseases in children. Although not intended to be a comprehensive review of this broad field, it provides a framework for appreciating the complexity of these diseases and for effectively managing them.