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

Omalizumab beyond asthma

INTRODUCTION

Omalizumab has been demonstrated to be a successful therapy in the management of asthma through reduction of patient's symptoms and use of inhaled corticosteroids. The effect of omalizumab is achieved by immunoglobulin E (IgE) blockage and other secondary mechanisms resulting from this blockage. Because other diseases have an important IgE mediation in their physiopathology, the question arises as to if omalizumab would be useful in the treatment of other IgE-mediated diseases.

OBJECTIVE

We present an overview of the experimental studies and clinical reports evaluating the use of omalizumab in diseases different to asthma including atopic dermatitis, urticaria, eosinophilic gastrointestinal disorders, idiopathic anaphylaxis, latex allergy, hymenoptera venom allergy, and other IgE diseases.

METHODS

We reviewed the literature using PUBMED, EMBASE, and LILACS for publications which used omalizumab in the treatment of patients with allergic diseases or any other diseases. Complete articles published in English, Spanish or Portuguese were included.

CONCLUSION

There is not enough evidence to support the regular use of omalizumab in IgE diseases other than asthma. However, some experimental and clinical investigations indicate that omalizumab could be a therapeutic option in several allergic diseases like atopic dermatitis, urticaria, and eosinophilic gastrointestinal disorders. More control studies are needed in each IgE disease to evaluate the efficacy and safety of omalizumab in IgE mediated diseases.

Omalizumab protects against allergen- induced bronchoconstriction in allergic (immunoglobulin E-mediated) asthma

BACKGROUND

Omalizumab has been shown to suppress responses to inhaled allergens in allergic asthma patients with pretreatment immunoglobulin E (IgE) ≤700 IU/ml. To extend current dosing tables, we evaluated the potential of high omalizumab doses to block allergen-induced bronchoconstriction in patients with higher IgE levels.

METHODS

Asthmatic adults (18-65 years; body weight 40-150 kg) were divided into groups according to screening IgE (group 1: 30-300 IU/ml; group 2: 700-2,000 IU/ml) and randomized 2:1 to omalizumab/placebo every 2 or 4 weeks for 12-14 weeks. Allergen bronchoprovocation (ABP) testing was performed before treatment and at weeks 8 and 16. The primary efficacy endpoint, the early-phase allergic response (EAR), was defined as the maximum percentage drop in forced expiratory volume in 1 s during the first 30 min after ABP. Serum free IgE was determined as a pharmacodynamic endpoint, and the exhaled fractional concentration of nitric oxide (FE(NO)) was an exploratory endpoint.

RESULTS

Fifty patients were included in the study. Omalizumab improved EAR; at week 8, EAR was 23.1% for placebo, 9.3% in group 1 (p = 0.018 versus placebo) and 5.6% in group 2 (p < 0.001). At week 16, EAR was 20%, 11.8% (p = 0.087) and 5.1% (p < 0.001), respectively. Free IgE decreased in groups 1 and 2 and remained <50 ng/ml in all patients during weeks 6-16. Omalizumab completely suppressed FE(NO) increases after ABP in both groups.

CONCLUSIONS

Omalizumab blocked early asthmatic responses over a broad range of IgE/body weight combinations. Extending the dosing tables enables omalizumab to benefit a wider range of patients.

How to diagnose and phenotype asthma

Asthma has been described as a chronic disease of the airways characterized by variable airflow obstruction, airway hyperresponsiveness, and airway inflammation. This review discusses the diagnosis and phenotyping of asthma, with a special emphasis on phenotyping based on the nature of cellular inflammation and radiological imaging and how this could be used to direct the treatment of asthma and, in the future, to apply specifically directed therapies to specific phenotypes.

Rationale for the use of immunomodulatory therapies in the Global Initiative for Asthma (GINA) step V asthma other than oral glucocorticosteroids

Asthma is a major problem worldwide, which is estimated to affect 300 million individuals. The global prevalence ranges from 1% to 18% of the population. The incidence, morbidity and mortality of the condition have increased over the last 50 years despite the development of new anti-asthmatic drugs. Fewer than 1% of the asthmatic population are steroid-dependent, but these patients consume most of the resources and time at asthma units. The consensus documents published by professional societies all support a stepwise therapeutic approach for asthma. However, patients who require frequent or continuous oral corticosteroid administration have received little attention. Due to the severe side-effects of oral corticosteroids when administered over long periods or at high doses, many drugs have been assessed in the search for a possible corticosteroid-sparing agent. Recently, the update of the Global Initiative for Asthma (GINA) introduced a new drug--omalizumab--as an alternative to oral corticosteroids in patients included in step V. Other alternatives include immunosuppressive drugs, among which methotrexate has been found to offer the best benefit/risk ratio. This paper will review, comment and criticize the evidence of the effectiveness of immunomodulatory drugs, as an alternative to oral glucocorticosteroid treatment in GINA step V asthma patients. The experience of the authors combined with the information of the literature will lead to the conclusion that methotrexate and omalizumab are the only advisable drugs and will clarify when and how these drugs should be used.

Impact of omalizumab on emergency-department visits, hospitalizations, and corticosteroid use among patients with uncontrolled asthma

BACKGROUND

Omalizumab is a monoclonal antibody indicated for moderate to severe allergic asthma patients with inadequately controlled symptoms.

OBJECTIVE

To evaluate the impact of omalizumab on emergency department (ED) visits, hospitalizations, and corticosteroid use among patients with uncontrolled asthma using high-dose inhaled corticosteroids (ICS) and long-acting beta2-agonists (LABA).

METHODS

Health insurance claims from the MarketScan database (2002Q1-2009Q1) were analyzed. Patients with 12 months or more of continuous insurance coverage before and after the first omalizumab dispensing, 8 or more weeks of high-dose ICS use, 8 or more weeks of LABA use, and uncontrolled asthma at baseline were included. A retrospective analysis was conducted to quantify the impact of omalizumab on resource use by comparing ED visits, hospitalizations, and corticosteroid use 1 year before and after omalizumab initiation. A 1-year period was chosen to cover any potential seasonality impacts.

RESULTS

In total, 644 patients (mean age, 49.9; female, 59.2%) formed the study population. Omalizumab was associated with a 48.6% reduction in the proportion of patients with 1 or more asthma-related ED visits (pre vs post-omalizumab period: 21.4% vs 11.0%; P < .001) and a 40.8% reduction in asthma-related hospitalizations (25.0% vs 14.8%, respectively, P < .001). Compared with the pre-omalizumab period, the use of ICS decreased significantly after omalizumab initiation (7.8 vs 6.5 dispensings, P < .001; 41.9% of patients had a reduction in ICS use). A similar reduction in oral corticosteroid use was observed (5.0 vs 3.6 dispensings, P < .001; 53.3% of patients had a reduction in oral corticosteroid use).

CONCLUSION

The current analysis showed that omalizumab treatment initiation was associated with significant reductions in ED visits, hospitalizations, and corticosteroid use.

Omalizumab versus 'usual care': results from a naturalistic longitudinal study in routine care

BACKGROUND

It is unclear how far the superior efficacy of omalizumab, established in randomized controlled clinical trials of patients with severe allergic asthma (SAA), translates into routine practice and when compared to matched controls.

METHODS

New-onset omalizumab-treated (OT) patients with SAA (n = 53) were compared to a matched control group of usual-care (UC) patients (n = 53). Treatment and procedures were naturalistic. Subsequent to a baseline assessment, patients were followed up over at least 6 months with at least two follow-up assessments. Primary clinical outcomes were the number of asthma attacks, persistence of asthma symptoms and degree of control [asthma control test (ACT), Global Initiative for Asthma]. Secondary outcome criteria were quality of life (Euro-Qol 5D) and number of medications. For each outcome we compared within-group effects from baseline to 6-month follow-up as well as between-group effects.

RESULTS

OT patients showed significant improvements in number [effect size (ES) = 0.03] and frequency (ES = 0.04) of asthma attacks as well as asthma control (ES = 0.09), whereas controls revealed no significant improvements in these measures. Further improvements in the OT group were found for 'perceived control always' (ACT, p = 0.006), no impairment (ACT, p = 0.02), reduction of sickness days (p = 0.002) and number of medications needed (p = 0.001).

CONCLUSIONS

Substantial beneficial effects of omalizumab, similar to those observed in controlled trials and after marketing studies, were confirmed, particularly with regard to the reduction of asthma attacks, persistence of symptoms, asthma control and reduction of concomitant asthma medications. This study provides a tougher test and generalizable evidence for the effectiveness of omalizumab in routine care.

Asthma phenotypes: the evolution from clinical to molecular approaches

Although asthma has been considered as a single disease for years, recent studies have increasingly focused on its heterogeneity. The characterization of this heterogeneity has promoted the concept that asthma consists of multiple phenotypes or consistent groupings of characteristics. Asthma phenotypes were initially focused on combinations of clinical characteristics, but they are now evolving to link biology to phenotype, often through a statistically based process. Ongoing studies of large-scale, molecularly and genetically focused and extensively clinically characterized cohorts of asthma should enhance our ability to molecularly understand these phenotypes and lead to more targeted and personalized approaches to asthma therapy.

Viral infections and atopy in asthma pathogenesis: new rationales for asthma prevention and treatment

Prospective birth cohort studies tracking asthma initiation and consolidation in community cohorts have identified viral infections occurring against a background of allergic sensitization to aeroallergens as a uniquely potent risk factor for the expression of acute severe asthma-like symptoms and for the ensuing development of asthma that can persist through childhood and into adulthood. A combination of recent experimental and human studies have suggested that underlying this bipartite process are a series of interactions between antiviral and atopic inflammatory pathways that are mediated by local activation of myeloid cell populations in the airway mucosa and the parallel programming and recruitment of their replacements from bone marrow. Targeting key components of these pathways at the appropriate stages of asthma provides new opportunities for the treatment of established asthma but, more crucially, for primary and secondary prevention of asthma during childhood.

Asthma outcomes: exacerbations

BACKGROUND

The goals of asthma treatment include preventing recurrent exacerbations. Yet there is no consensus about the terminology for describing or defining "exacerbation" or about how to characterize an episode's severity.

OBJECTIVE

National Institutes of Health institutes and other federal agencies convened an expert group to propose how asthma exacerbation should be assessed as a standardized asthma outcome in future asthma clinical research studies.

METHODS

We used comprehensive literature reviews and expert opinion to compile a list of asthma exacerbation outcomes and classified them as either core (required in future studies), supplemental (used according to study aims and standardized), or emerging (requiring validation and standardization). This work was discussed at a National Institutes of Health-organized workshop in March 2010 and finalized in September 2011.

RESULTS

No dominant definition of "exacerbation" was found. The most widely used definitions included 3 components, all related to treatment, rather than symptoms: (1) systemic use of corticosteroids, (2) asthma-specific emergency department visits or hospitalizations, and (3) use of short-acting β-agonists as quick-relief (sometimes referred to as "rescue" or "reliever") medications.

CONCLUSIONS

The working group participants propose that the definition of "asthma exacerbation" be "a worsening of asthma requiring the use of systemic corticosteroids to prevent a serious outcome." As core outcomes, they propose inclusion and separate reporting of several essential variables of an exacerbation. Furthermore, they propose the development of a standardized, component-based definition of "exacerbation" with clear thresholds of severity for each component.

Omalizumab in the treatment of asthma

Omalizumab was introduced in 2003 and is the first asthma drug to target IgE, the allergic antibody that initiates the allergic cascade. Well-controlled studies and post-marketing clinical experience have shown it to be an effective and safe medication. Treatment guidelines now recommend omalizumab as an add-on option for patients with moderate-to-severe allergic asthma uncontrolled on high-dose inhaled corticosteroids and long-acting β-agonists. Despite initial concerns, there is no evidence of any association with malignancy at this time. In our opinion, omalizumab is well-tolerated and significantly improves pulmonary function, decreases clinical symptoms and improves the quality of life in patients with uncontrolled allergic asthma.

Effect of omalizumab as add-on therapy on asthma-related quality of life in severe allergic asthma: a Brazilian study (QUALITX)

OBJECTIVE

To assess the impact of omalizumab as an add-on therapy to standard treatment with inhaled corticosteroids (ICS) and long-acting beta-2 agonists (LABA) on asthma-related quality of life (QoL) in patients with severe allergic asthma.

METHODS

This was a 20-week, randomized, open-label, study involving Brazilian patients (>12 years) with severe persistent allergic asthma inadequately controlled despite regular treatment with, at least, ICS (≥500 μg/day fluticasone or equivalent) + LABA. The primary objective was to assess the mean change from baseline in overall Asthma-related Quality of Life Questionnaire (AQLQ) score in omalizumab-treated patients compared with the control group. Secondary outcome measures included rescue medication use, incidence of asthma exacerbations, perception of treatment efficacy among patients, mean change from baseline in AQLQ score, and >1.5-point increase in overall AQLQ score.

RESULTS

In the omalizumab group, overall AQLQ score was 3.2 (0.9) (mean [SD]) at baseline and 4.4 (1.3) at week 20 versus 3.0 (1.0) at baseline and 3.0 (1.1) at week 20 in the control group. Mean change from baseline on overall AQLQ score at week 20 in the omalizumab group was 1.2 (0.2) versus 0 (0.1) in the control group, showing a significant increase in scores from baseline in the omalizumab group (p < .001). There was also a statistically significant difference (p < .001) in the number of patients who showed a >1.5-point increase from baseline in overall AQLQ score after 20 weeks, thus indicating a better QoL in the omalizumab group. There was no significant difference with respect to the use of rescue medication, incidence of asthma exacerbation, and adverse events between treatment groups. The global evaluation of treatment effectiveness was significantly better for omalizumab (p < .001).

CONCLUSION

Omalizumab was well tolerated and significantly improved the overall AQLQ score. Hence, it is a potential add-on therapy for severe persistent allergic asthma not controlled by standard prescribed treatment in Brazilian patients.

Targeting IgE in asthma

PURPOSE OF REVIEW

IgE plays a pivotal role in allergic asthma especially in the acute response to antigen and in the propagation of airway inflammation. Therefore, it has become apparent that targeting this antibody and blocking its function may lead to significant clinical effects in some patients with the disease. In this review, we describe the role of IgE in asthma and provide an update on the therapeutic implications of targeting this mediator in patients with severe allergic disease. We also outline future needs of research in this area.

RECENT FINDINGS

Several randomized clinical trials as well as observational real-world studies have confirmed the long-term efficacy of omalizumab in improving clinical outcomes when added to guideline-recommended maintenance of asthma medications (inhaled corticosteroids and long-acting β2-agonists) in patients with moderate-to-severe asthma. Recent pooled data from randomized clinical trials and from a large prospective cohort study provide reassurance about the long-term safety of omalizumab. Future research should explore the long-term effects of omalizumab on the natural history of the disease and identify more accurate predictors of response to this treatment.

SUMMARY

The anti-inflammatory effects of omalizumab at different sites of allergic inflammation and its clinical benefits in patients with allergic asthma emphasize the fundamental importance of IgE in allergic inflammation.

A 26-week, randomized, double-blind, placebo-controlled, multicenter study to evaluate the effect of omalizumab on asthma control in patients with persistent allergic asthma

OBJECTIVE

The 2007 National Heart, Lung, and Blood Institute (NHLBI) asthma guidelines shifted the focus of care from asthma severity to ongoing assessment of asthma control using the components of impairment and risk. We evaluated the effect of omalizumab on asthma control in patients with persistent allergic asthma inadequately controlled with NHLBI Step 4 or above asthma therapy.

METHODS

In this double-blind, placebo-controlled study, patients ≥12 years (n = 271) received omalizumab (n = 136) or placebo (n = 135) every 2 or 4 weeks for 24 weeks. The primary efficacy variable, change from baseline in Asthma Control Test (ACT) total score, and Investigator's Global Evaluation of Treatment Effectiveness (IGETE, secondary efficacy variable) were evaluated at week 24.

RESULTS

ACT score improved more with omalizumab compared with placebo (least squares means [LSMs]: 5.01, 4.36); however, the difference was not significant (p = .1779). Similarly, IGETE was not significantly different (p = .1177), but more patients treated with omalizumab (26/127, 20%) compared with placebo (19/131, 15%) had IGETE rated as "Excellent." Significant benefits were observed for omalizumab compared with placebo for change in ACT score (LSMs: 6.66, 5.27; p = .0334) and IGETE (p = .0321) at week 24 in a subgroup of patients with very poorly controlled asthma (ACT ≤ 15) at baseline. There were no significant differences for the subgroup of patients with forced expiratory volume in 1 second ≤ 80% predicted at baseline. Adverse events (AEs) were similar between groups with no drug-related serious AEs or deaths.

CONCLUSIONS

For allergic asthma patients with NHLBI Step 4 or above asthma therapy, omalizumab consistently improved asthma control; however, compared with placebo, differences were not significant. Placebo-treated patients had substantial improvement in their ACT score, which may have limited the ability to detect differences between treatment groups. Subgroup analyses showed significant improvements with omalizumab versus placebo in patients with very poorly controlled asthma.

Current treatment of severe asthma

Severe asthma is considered a heterogeneous disease in which a variety of clinical, physiological and inflammatory markers determine disease severity. Pivotal studies in the last 5 years have led to substantial progress in many areas, ranging from a more accurate definition of truly severe, refractory asthma, to classification of the disease into distinct clinical phenotypes, and introduction of new therapies. This review focuses on three common clinical phenotypes of severe asthma in adults (early onset severe allergic asthma, late onset non-atopic eosinophilic asthma, late onset non-eosinophilic asthma with obesity), and provides an overview of recent developments regarding treatment options that are best suited for each of these phenotypes.

[Asthma exacerbations: pharmacological prevention]

Asthma exacerbations are responsible for many emergency medical interventions and account for a significant proportion of the health costs of the disease. Increased airway inflammation is a key feature of exacerbations in asthma and therefore inhaled corticosteroids (ICS) are considered as first-line therapy for long-term asthma control. ICS have been demonstrated to reduce the risk of asthma exacerbations, as well as improving lung function. Oral leukotriene receptor antagonists also reduce the incidence of asthma exacerbations but are less effective than ICS. In patients with inadequately controlled persistent asthma despite low-dose ICS, the addition of a long-acting inhaled beta-agonist (LABA) should be considered. LABA should not be given alone and should always be associated with ICS in asthma. The anti-immunoglobulin E antibody, omalizumab, reduces severe exacerbations and emergency visits in patients with severe allergic asthma. In clinical trials measurement of the inflammatory response in induced sputum could provide information concerning appropriate drug therapy. Asthma-associated comorbidities should be investigated and treated, particularly in severe asthma. Despite a high prevalence of both gastro-oesophageal reflux and allergic rhinitis among patients with asthma, treatment with proton-pump inhibitors or nasal corticosteroids does not reduce the rate of asthma exacerbations.

Omalizumab decreases IgE production in patients with allergic (IgE-mediated) asthma; PKPD analysis of a biomarker, total IgE

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Omalizumab is a humanized anti-IgE monoclonal antibody that binds and captures circulating IgE, preventing interaction with receptors on mast cells and basophils, thereby interrupting the allergic cascade. It has a well-characterized efficacy and safety profile in patients with asthma. While omalizumab is known to reduce serum free IgE concentrations, effects on total IgE and IgE production are less well characterized.

WHAT THIS STUDY ADDS

(i) Confirmation of prior hypotheses that IgE production can decrease with time when patients are given anti-IgE therapy; (ii) guidance on a biomarker, total IgE, which can be used to ascertain whether individual patients experience a change in their IgE production; and (iii) a way to assess whether patients' IgE production has been sufficiently down-regulated such that they may consider stopping anti-IgE therapy.

AIM

To determine whether excessive IgE production by patients with atopic allergic asthma decreases with omalizumab therapy.

METHODS

Omalizumab, free and total IgE data were obtained from an epidemiological study and six randomized, double-blind, placebo-controlled trials in patients with allergic asthma. The binding between omalizumab and IgE together with the production and elimination of IgE were modelled as previously, except that, in order to explain why total IgE was decreasing over a period of 5 years, the expression of IgE was allowed to change.

RESULTS

The prior constant IgE production model failed to converge on the data once long-term observations were included, whereas models allowing IgE production to decrease fitted. A feedback model indicated that, on average, IgE production decreased by 54% per year. This model was further developed with covariate searches indicating clinically small but statistically significant effects of age, gender, body mass index and race on some parameters. Model predictions were checked internally and externally against 3-5 year data from paediatric and adult atopic asthmatic patients and externally against extensive total IgE data from a long-duration (>1 year) phase 1 study which was not used in the model building.

CONCLUSIONS

A pharmacokinetic-pharmacodynamic model incorporating omalizumab-IgE binding and feedback for control of IgE production indicates that omalizumab reduces production of IgE. This raises the possibility that indefinite treatment may not be required, only for perhaps a few years. After the initial accumulation, total IgE should provide a means to monitor IgE production and guide individual treatment decisions.

Omalizumab reduces corticosteroid use in patients with severe allergic asthma: real-life experience in Israel

OBJECTIVE

Approved by the FDA in 2003, omalizumab is the first recombinant humanized monoclonal anti-immunoglobulin E antibody developed for the treatment of allergic asthma. Due to the heterogeneity of asthma symptoms, investigation of the efficacy of omalizumab in patients outside controlled trials is particularly important. The purpose of the current study was to evaluate the efficacy of omalizumab as an add-on treatment for allergic asthma in a real-life setting in Israel.

METHODS

This was a retrospective study based on patient records and computerized database for drug dispensing, emergency room visits, and hospital admissions.

RESULTS

The sample comprised 33 individuals (18 men, 15 women; mean age 50.0 ± 12.2, range 25-79) who were treated with omalizumab for severe allergic asthma for a duration of at least 16 weeks. After the initiation of omalizumab therapy, the number of patients who used oral or injected corticosteroids decreased (p < .003, .03, respectively), as did the median dosage of oral corticosteroids (p < .02). Visits to the emergency room decreased from an incidence of 0.526 visits per person-year to an incidence of 0.246 per person-year (p < .05). No adverse reactions to omalizumab were observed.

CONCLUSION

Omalizumab as an add-on therapy reduced the use of corticosteroids and improved the control of asthma, as evidenced by reduced asthma-related emergency room visits. This study supports both controlled and uncontrolled studies that have demonstrated the efficacy and safety of omalizumab, and particularly those that demonstrated effectiveness among severe asthma patients. "Real-life" studies are important to identify patients who will most benefit from omalizumab therapy.

Long-term omalizumab treatment in severe allergic asthma: the South-Eastern Mediterranean "real-life" experience

BACKGROUND

Omalizumab is a recombinant humanized anti-IgE monoclonal antibody indicated as an add-on treatment for severe allergic asthma, inadequately controlled despite high dose of inhaled corticosteroids (ICS) and long-acting b2-agonists.

OBJECTIVES

Medical registries were used to evaluate the 4 months, 1 and 4 years effectiveness of omalizumab treatment, in a non-interventional, observational "real-life" study.

METHODS

Sixty patients with severe persistent allergic asthma from 5 South-Eastern Mediterranean centres from Crete and Cyprus were evaluated. Effectiveness outcomes included spirometry, severe asthma exacerbations rate, level of asthma control (ACT), and additional asthma medication (inhaled steroids).

RESULTS

Outcome variables improved after 4 months and sustained after 1 and 4 years treatment with Omalizumab. FEV1 improved statistically significant at all time points versus baseline [ΔFEV1 (% pred.) = +21 p = 0.008 at 4 months, ΔFEV1 (% pred.) = +24.5 p < 0.0001 at 4 years after treatment]. Similarly, FVC increased statistically significant versus baseline [ΔFVC (% pred.) = +20 p = 0.002 at 4 months, ΔFVC (% pred.) = +22.6 p = 0.0002 at 4 years]. The level of asthma control as evaluated by ACT was significantly improved after treatment (+12% p = 0.001 at 4 months, +24% p < 0.0001 at 4 years). Omalizumab treatment reduced significantly asthma exacerbations rate (-65% p = 0.0002 at 1 year, and -70% p < 0.0001 at 4 years). The use of inhaled steroids decreased statistically significant after 4 months (p = 0.017), 1 year (p = 0.029) and 4 years (p = 0.014) of omalizumab treatment.

CONCLUSIONS

This long-term "real-life" study demonstrated significant improvement in lung function and other clinical outcomes after omalizumab treatment, evident at 4 months, and sustained after 1 and 4 years suggesting its efficacy in severe allergic asthma, in the "real-life" practice.

Management of severe asthma exacerbation in children

BACKGROUND

Asthma is a common disease in children and acute severe asthma exacerbation can be life-threatening. This article aims to review recent advances in understanding of risk factors, pathophysiology, diagnosis and treatment of severe asthma exacerbation in children.

DATA SOURCES

Articles concerning severe asthma exacerbation in children were retrieved from PubMed. Literatures were searched with MeSH words "asthma", "children", "severe asthma exacerbation" and relevant cross references.

RESULTS

Severe asthma exacerbation in children requires aggressive treatments with β2-agonists, anticholinergics, and corticosteroids. Early initiation of inhaled β-agonists and systemic use of steroids are recommended. Other agents such as magnesium and aminophylline have some therapeutic benefits. When intubation and mechanical ventilation are needed, low tidal volume, controlled hypoventilation with lower-than-traditional respiratory rates and permissive hypercapnia can be applied.

CONCLUSIONS

Researchers should continue to detect the risk factors, pathophysiology, diagnosis and treatment of severe asthma exacerbation in children. More studies especially randomized controlled trials are required to evaluate the efficacy and safety of standard and new therapies.

Immune modulation for treatment of allergic disease

Immune modulation for treatment of allergic diseases aims to decrease the pathologic immune response rather than to cause a return to an immunologically naive or unresponsive state. Our expanding knowledge of innate and adaptive immune responses at the molecular level has led to development of immunomodulators for several allergic diseases, particularly asthma, allergic rhinitis, and eosinophilic esophagitis. Although successful immune modulation in mouse models of allergic disease have often failed to translate into significant results in human clinical trials, much has been learned about the pleotropic nature of cytokines and their effector mechanisms and of the varied phenotypes of allergic disease. We examine strategies of immune modulation in allergic diseases that have undergone human clinical trials, all with the common goal of decreasing the T-helper 2 (Th2) response, but through different mechanisms: blocking critical Th2 cytokines, inhibiting Th2 cytokine synthesis, blocking critical Th2 effector molecules, inhibiting important cells in the Th2 response, and stimulating Th1 responses. Therapies directed against specific effector molecules, such as immunoglobulin E and prostaglandin D2, hold promise in immune modulation of allergic disease, as do targeting the IL-4/IL-13 receptor and augmenting Th1/Th2 balance with Toll-like receptor agonists.

Monoclonal antibodies for the treatment of asthma

Asthma is a chronic inflammatory disease of the airways which can have a detrimental effect on quality of life and in extreme cases cause death. Although the majority of patients can control their asthma symptoms with a combination of steroids and beta agonists there is still a group of patients whose asthma remains symptomatic despite the best available treatment. These severe asthmatic patients represent the unmet medical need in asthma and are the focus of those developing novel monoclonal antibody based drugs. The complex networks of cytokines and cells involved in the pathology of asthma provide plenty of scope for intervention with monoclonal antibody based drugs which are able to block cytokine or chemokine receptor interactions, deplete cells expressing a specific receptor or block cell/cell interactions. At present anti-IgE (Xolair©) is the only monoclonal antibody based drug approved for the treatment of asthma. However, a number of other antibody based drugs have been clinically tested in asthma including anti-IL-5, anti-IL-4, anti-IL-13, anti-TNFα, anti-CCR3, anti-CCR4 and anti-OX40L. This review will examine the development of these monoclonal antibody based therapies. Since many of these therapies have targeted key pathways in asthma pathology these studies provide information on patient stratification and asthma pathology.

Can anti-IgE therapy prevent airway remodeling in allergic asthma?

Airway remodeling is a central feature of asthma. It is exemplified by thickening of the lamina reticularis and structural changes to the epithelium, submucosa, smooth muscle, and vasculature of the airway wall. Airway remodeling may result from persistent airway inflammation. Immunoglobulin E (IgE) is an important mediator of allergic reactions and has a central role in airway inflammation and asthma-related symptoms. Anti-IgE therapies (such as omalizumab) have the potential to block an early step in the allergic cascade and therefore have the potential to reduce airway remodeling. The reduction in free IgE levels following anti-IgE therapy leads to reductions in high-affinity IgE receptor (FcεRI) expression on mast cells, basophils, and dendritic cells. This combined effect results in attenuation of several markers of inflammation, including peripheral and bronchial tissue eosinophilia and levels of granulocyte macrophage colony-stimulating factor, interleukin (IL)-2, IL-4, IL-5, and IL-13. Considering the previously demonstrated anti-inflammatory effects of anti-IgE therapy, along with results from a small study showing continued benefit after discontinuation of long-term treatment, a larger study to assess its effect on markers of airway remodeling is underway.

Optimal management of severe/refractory asthma

Asthma is a chronic inflammatory disease of the airways, affecting approximately 300 million people worldwide. Asthma results in airway hyperresponsiveness, leading to paroxysmal symptoms of wheeze, cough, shortness of breath, and chest tightness. When these symptoms remain uncontrolled, despite treatment with high doses of inhaled and ingested corticosteroids, asthmatic patients are predisposed to greater morbidity and require more health care support. Treating patients with severe asthma can be difficult and often poses a challenge to physicians when providing ongoing management. This clinical review aims to discuss the definition, prevalence and evaluation of severe asthmatics, and provides a review of the existing pharmacologic and non-pharmacologic treatment options.

Asthma phenotypes in adults and clinical implications

It is becoming increasingly recognized that asthma is a heterogeneous disease, whether based on clinical factors, including the patient's age at diagnosis, symptom spectrum and treatment response, triggering factors, or the level and type of inflammation. Attempts to analyze the importance of these characteristics to the clinical presentation of asthma have led to the appreciation of numerous separate and overlapping asthma phenotypes. However, these approaches are 'biased' and based on the clinician/scientist's own experience. Recently, unbiased approaches have also been attempted using both molecular and statistical tools. Early results from these approaches have supported and expanded on the clinician's concepts. However, until specific biologic markers are identified for any of these proposed phenotypes, the definitive nature of any phenotype will remain speculative.

Omalizumab in patients with severe asthma: the XCLUSIVE study

BACKGROUND AND AIMS

Although the efficacy and safety of omalizumab (OMA) in uncontrolled severe allergic asthma has been demonstrated in several randomised controlled trials (RCTs), information on the treatment in a practice-related setting is limited. Thus, the purpose of this prospective multi-centre study (XCLUSIVE) was to investigate the efficacy, compliance and utilisation of OMA therapy in real-life clinical practice in Germany.

METHODS

One hundred ninety-five asthmatic patients initiated on anti-Immunoglobulin E (IgE) IgE treatment were followed-up for 6 months. Forced expiratory volume in 1 s (FEV(1) ), exacerbation rate, days of absence, asthma symptoms [Asthma Control Questionnaire (ACQ)], a Global Evaluation of Treatment Effectiveness (GETE) and medication use were assessed.

RESULTS

Measured outcome variables improved after a 16-week treatment period with OMA (FEV(1) +13.7% predicted P < 0.05, exacerbation rate -74.9% P < 0.0001, days of absence -92.1% P < 0.001, ACQ -43.7% P < 0.0001). Investigators evaluated the effectiveness of OMA by GETE in 78.8% as excellent or good (responder), and in 12.6%/8.6% as moderate/poor or worse (non-responder). Responders demonstrated better improvement of FEV(1), exacerbation rate, days of absence, ACQ and reduction of oral corticosteroids compared with non-responders.

CONCLUSION

Results of effectiveness strongly suggest that the efficacy demonstrated in RCTs can be transposed to a clinical practice-related setting.

Helping patients attain and maintain asthma control: reviewing the role of the nurse practitioner

Nurse practitioners (NPs) have a unique opportunity as frontline caregivers and patient educators to recognize, assess, and effectively treat the widespread problem of uncontrolled asthma. This review provides a perspective on the role of the NP in implementing the revised National Asthma Education and Prevention Program (NAEPP) Guidelines put forth by the National Heart, Lung, and Blood Institute, thereby helping patients achieve and maintain asthma control. A literature search of PubMed was performed using the terms asthma, nurse practitioner, asthma control, burden, impact, morbidity, mortality, productivity, quality of life, uncontrolled asthma, NAEPP guidelines, assessment, pharmacotherapy, safety. Despite the increased morbidity and mortality and impaired quality of life attributable to uncontrolled asthma, the 2007 NAEPP asthma guidelines are greatly underused. NPs have an opportunity to identify patients at risk and provide enhanced care and education for asthma control. Often, NPs can prescribe medication for and manage these patients, but it is necessary to be able to discern which patients require referral to a specialist.

Future forms of immunotherapy and immunomodulators in allergic disease

Future forms of immunotherapy, particularly toll-like receptor agonists, have shown promising results in animal models of allergic disease although most have failed to translate into successful human clinical trials. These results have helped to elucidate the pleotropic roles of cytokines as well as the diverse phenotypes of allergic diseases, particularly asthma. The goals of these therapies are to improve patient symptoms and quality of life, to prevent and favorably alter disease course, and to maintain a good risk/benefit ratio along with a cost-effective profile.

Changes in total IgE plasma concentration measured at the third month during anti-IgE treatment predict future exacerbation rates in difficult-to-treat atopic asthma: a pilot study

In severe, difficult-to-treat atopic asthma with sensitization to perennial allergens, monoclonal antibodies directed against immunoglobulin E (IgE) are recognized to be clinically effective. Omalizumab, a recombinant monoclonal antibody, selectively binds to the high-affinity C-epsilon 3 site of human IgE and inhibits the inflammatory cascade in response to antigenic stimuli. Currently, no indicator is available for predicting patients' responsiveness to long-term omalizumab treatment. This study aims to assess the relationship between early changes in plasma IgE concentration and major outcome variables over a 12-month course of omalizumab.

METHODS

Twenty-three nonsmoking, severe asthmatics (14 females; mean age 47.3 years ± 12.0 SD; mean BMI 25.8 kg/m(2) ± 9.6 SD) sensitized to perennial allergens and unresponsive to high doses of common therapies were evaluated during a 12-month period of omalizumab treatment. Variables included total IgE plasma concentrations, Forced Expiratory Volume 1 second (FEV(1)) symptom complaints (Asthma Control Test (ACT) score), number of emergency visits, hospitalizations, and exacerbations. The Wilcoxon signed-rank test was used to compare changes observed after the 1-year omalizumab treatment versus baseline. Statistical modelization was used to determine possible relationships between changes in outcomes after 12 months and early changes in plasma IgE (after 3 months of treatment).

RESULTS

The number of emergency visits, hospitalizations, and exacerbations decreased (p < .004, p < .001, and p < .001, respectively) over the 12-months. In contrast, FEV(1) and ACT score substantially increased (both p < .001); the ACT score reaching maximum after only 3 months. The S model showed the best fit and proved the strict relationship between the increase in IgE after 3 months and the exacerbation rate over the 1-year survey (threshold value of ≥250 IU/ml, p < .001). The improvement in FEV(1) was independent of the increase in IgE.

CONCLUSIONS

When confirmed on a larger population, early changes in IgE may be used as a predictor of future responders to omalizumab in terms of exacerbation rate, thus minimizing the economic burden of anti-IgE therapy.

Development of the Asthma Control Composite outcome measure to predict omalizumab response

BACKGROUND

Previous assessments of response to omalizumab were based on diary-based data rather than standard validated instruments. A composite instrument that translates diary-based data into standard validated asthma control measures would characterize patient response to treatment in terms of current asthma control definitions.

OBJECTIVE

To develop the Asthma Control Composite (ACC) tool, using real-time diary-based data to predict treatment response in terms of asthma control.

METHODS

The ACC tool was derived retrospectively using pooled data from two phase 3 studies in patients with moderate to severe allergic asthma. Patients were randomized to receive subcutaneous omalizumab or placebo for 16 weeks plus stable beclomethasone dipropionate therapy, followed by a 3-month corticosteroid reduction period and 5-month double-blind safety extension. Control was assessed as "complete," "good," or "not controlled," based on a composite score of 4 elements: rescue medication (puffs/day), total asthma symptom score, average number of awakening nights/28 days, and activity limitation.

RESULTS

The ACC was mapped to standard validated measures of patient-reported outcomes, with results consistent with clinical outcomes. The proportion of patients with baseline uncontrolled asthma achieving "good" or "complete" asthma control was 48% with omalizumab and 32% with placebo at approximately 4 months. The mean composite score also was improved with omalizumab (3.52) vs placebo (2.56) at approximately 4 months.

CONCLUSIONS

The ACC tool accurately reflects asthma control in moderate to severe asthma patients eligible for biological therapy. Unlike the ACT, which has not been validated in this patient population, the ACC shows promise as an asthma control assessment tool in patients with moderate to severe asthma.

Current and future applications of the anti-IgE antibody omalizumab

IgE antibodies are a pivotal factor in pathophysiology of allergic diseases, and the possibility of reducing their level by anti-IgE has long been envisioned. Following several attempts, an effective biologic agent was obtained with the recombinant humanized mono-clonal antibody (rhuMAb)-E25, known as omalizumab. A number of controlled clinical trials demonstrated its efficacy and safety in the treatment of severe allergic asthma uncontrolled by standard drug treatment with maximal recommended doses, and treatment with omalizumab is currently included in international guidelines on asthma management. Other studies reported a clear effectiveness also in allergic rhinitis, but the cost of the anti-IgE treatment suggests its use in patients with rhinitis concomitant with asthma. Other indications to be further investigated are skin disorders such as atopic dermatitis and IgE-mediated urticaria, as well as adverse reactions to foods, with a particularly important role in preventing food-induced anaphylaxis. Finally, there are data indicating the usefulness of omalizumab when used in combination with allergen specific immunotherapy, in terms of reducing the adverse reactions to treatment and increasing the clinical efficacy.

New approaches to managing asthma: a US perspective

Despite remarkable advances in diagnosis and long-term management, asthma remains a serious public health concern. Newly updated expert guidelines emphasize the intra- and inter-individual variability of asthma and highlight the importance of periodic assessment of asthma control. These guidelines update recommendations for step-wise asthma treatment, address the burgeoning field of asthma diagnostics, and stress the importance of a patient and health care professional partnership, including written action plans and self monitoring. The field of asthma therapeutics is expanding rapidly, with promising new treatment options available or in development that may address some of the existing barriers to successful asthma management. These approaches simplify treatment, use combinations of agents in one delivery device that have complementary actions, or target specific pathways involved in asthma patho-physiology. Considerable activity is taking place in asthma pharmacogenetics. This review provides an overview of these new approaches to managing asthma, including their present status and future potential.

Unusual asthma syndromes and their management

Asthma usually presents with symptoms of wheeze, dyspnoea and cough. However, clinicians should be aware of atypical presentation of this disorder when cough is the main or only symptom in conditions such as cough-variant asthma, nonasthmatic eosinophilic bronchitis and atopic cough. Early diagnosis and treatment of these conditions with inhaled corticosteroids improves symptoms in the majority of patients. Up to 10% of patients with asthma remain poorly controlled in spite of optimal standard therapy. These patients have been encompassed under the term 'treatment-refractory asthma' (TRA), have the greatest morbidity and are responsible for more than 50% of healthcare costs. In this review we discuss investigations, management and pathophysiology of the various phenotypes of atypical presentations of asthma as well as novel biological agents licensed and those that have been reported in clinical trials in terms of their efficacy and safety in TRA.

Update on optimal use of omalizumab in management of asthma

Omalizumab is a humanized monoclonal anti-IgE antibody recently approved for the treatment of severe allergic asthma. This drug inhibits allergic responses by binding to serum IgE, thus preventing interaction with cellular IgE receptors. Omalizumab is also capable of downregulating the expression of high affinity IgE receptors on inflammatory cells, as well as the numbers of eosinophils in both blood and induced sputum. The clinical effects of omalizumab include improvements in respiratory symptoms and quality of life, paralleled by a reduction of asthma exacerbations, emergency room visits, and use of systemic corticosteroids and rescue bronchodilators. Omalizumab is relatively well-tolerated, and only rarely induces anaphylactic reactions. Therefore, this drug represents a valid option as add-on therapy for patients with severe persistent allergic asthma inadequately controlled by high doses of standard inhaled treatments.

Omalizumab in severe allergic asthma inadequately controlled with standard therapy: a randomized trial

BACKGROUND

Inhaled corticosteroids (ICS) and long-acting β(2)-agonists (LABAs) are recommended in patients with asthma that is not well-controlled; however, many patients continue to have inadequately controlled asthma despite this therapy.

OBJECTIVE

To evaluate the efficacy and safety of omalizumab in patients with inadequately controlled severe asthma who are receiving high-dose ICS and LABAs, with or without additional controller therapy.

DESIGN

Prospective, multicenter, randomized, parallel-group, double-blind, placebo-controlled trial. (ClinicalTrials.gov registration number: NCT00314575).

SETTING

193 investigational sites in the United States and 4 sites in Canada.

PATIENTS

850 patients aged 12 to 75 years who had inadequately controlled asthma despite treatment with high-dose ICS plus LABAs, with or without other controllers.

INTERVENTION

Omalizumab (n = 427) or placebo (n = 423) was added to existing medication regimens for 48 weeks.

MEASUREMENTS

The primary end point was the rate of protocol-defined exacerbations over the study period. Secondary efficacy end points included the change from baseline to week 48 in mean daily number of puffs of albuterol, mean total asthma symptom score, and mean overall score on the standardized version of the Asthma Quality of Life Questionnaire (AQLQ[S]). Safety end points included the frequency and severity of treatment-emergent adverse events.

RESULTS

During 48 weeks, the rate of protocol-defined asthma exacerbations was significantly reduced for omalizumab compared with placebo (0.66 vs. 0.88 per patient; P = 0.006), representing a 25% relative reduction (incidence rate ratio, 0.75 [95% CI, 0.61 to 0.92]). Omalizumab improved mean AQLQ(S) scores (0.29 point [CI, 0.15 to 0.43]), reduced mean daily albuterol puffs (-0.27 puff/d [CI, -0.49 to -0.04 puff/d]), and decreased mean asthma symptom score (-0.26 [CI, -0.42 to -0.10]) compared with placebo during the 48-week study period. The incidence of adverse events (80.4% vs. 79.5%) and serious adverse events (9.3% vs. 10.5%) were similar in the omalizumab and placebo groups, respectively.

LIMITATIONS

The results are limited by early patient discontinuation (20.8%). The study was not powered to detect rare safety events or the treatment effect in the oral corticosteroid subgroup.

CONCLUSION

In this study, omalizumab provided additional clinical benefit for patients with severe allergic asthma that is inadequately controlled with high-dose ICS and LABA therapy.

PRIMARY FUNDING SOURCE

Genentech and Novartis Pharmaceuticals.

Beneficial effects of treatment with anti-IgE antibodies (Omalizumab) in a patient with severe asthma and negative skin-prick test results

It is now well recognized that treatment with anti-IgE antibodies like omalizumab is a valuable option in patients with allergic asthma who remain symptomatic despite optimal treatment. To our knowledge, treatment with omalizumab in patients with nonallergic asthma has not been reported. We present and discuss a patient with severe asthma and elevated total IgE who had a negative radioallergosorbent (RAST) test result and a negative skin-prick test result; the patient showed a dramatic improvement with this treatment strategy.

Stratified medicine in selecting biologics for the treatment of severe asthma

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Omalizumab for pediatric asthma

IMPORTANCE TO THE FIELD

Omalizumab is of proven efficacy in the treatment of severe allergic bronchial asthma and works through inhibiting the activity of IgE and the allergic immune mechanism IgE mediates. It has been demonstrated to be efficacious in children with asthma but is not approved by the FDA for use in children below 12 years of age.

AREAS COVERED IN THIS REVIEW

Omalizumab is a 95% humanized monoclonal antibody that binds to circulating IgE at the same site on the Fc domain as the high-affinity IgE receptor, FcϵRI. This blocks the interaction between IgE and mast cells and basophils, thereby preventing the release of inflammatory mediators that cause allergic signs and symptoms.

WHAT THE READER WILL GAIN

From the review of the literatures and statements from the FDA, Genentec and Novartis, the reader will gain a better appreciation of the value of omalizumab in treatment of severe asthma and the current status of its reported side effects.

TAKE HOME MESSAGE

Omalizumab is of proven efficacy in adults and children with severe asthma and allows a markedly reduced dependence on oral and inhaled corticosteroids and decreased hospitalizations. A potential mechanism of omalizumab's effect on thrombus formation and cardiovascular effect is postulated.

Effects of omalizumab on changes in pulmonary function induced by controlled cat room challenge

BACKGROUND

Environmental exposure to cat allergen is common, and sensitization to cat allergens is strongly associated with asthma.

OBJECTIVE

We sought to examine the efficacy of omalizumab in preventing acute bronchoconstriction induced by environmental exposure to cat allergen.

METHODS

Patients with a history of cat allergen-induced asthma were randomized to treatment with omalizumab or placebo and exposed to cat allergen in a controlled chamber for up to 1 hour at baseline and after 16 weeks of treatment. The primary efficacy outcome was area under the curve for percentage decrease from prechallenge FEV(1) at week 16 for omalizumab-treated versus placebo-treated patients. FEV(1) was recorded before and every 10 minutes during the 1-hour challenge. Chest, nasal, and ocular symptoms were also monitored during cat chamber exposure as secondary end points.

RESULTS

The area under the curve for percentage decrease in FEV(1) was 15.2% per hour for omalizumab-treated patients (n = 32) and 27.3% per hour for placebo-treated patients (n = 33), reflecting 44% less reduction in FEV(1) and a treatment difference of -12.1% per hour (P = .0009; 95% CI, -19.0 to -5.2). Compared with placebo-treated patients, omalizumab-treated patients were also able to tolerate longer allergen exposure (P = .0006) and demonstrated significant reductions from prechallenge values in their chest symptom score (P < .0001) and nasal-ocular symptom score (P = .0002).

CONCLUSIONS

The severity of acute airway reactions and symptoms caused by controlled cat room exposure to allergens was significantly reduced by treatment with omalizumab.

Randomized trial of omalizumab (anti-IgE) for asthma in inner-city children

BACKGROUND

Research has underscored the effects of exposure and sensitization to allergens on the severity of asthma in inner-city children. It has also revealed the limitations of environmental remediation and guidelines-based therapy in achieving greater disease control.

METHODS

We enrolled inner-city children, adolescents, and young adults with persistent asthma in a randomized, double-blind, placebo-controlled, parallel-group trial at multiple centers to assess the effectiveness of omalizumab, as compared with placebo, when added to guidelines-based therapy. The trial was conducted for 60 weeks, and the primary outcome was symptoms of asthma.

RESULTS

Among 419 participants who underwent randomization (at which point 73% had moderate or severe disease), omalizumab as compared with placebo significantly reduced the number of days with asthma symptoms, from 1.96 to 1.48 days per 2-week interval, a 24.5% decrease (P<0.001). Similarly, omalizumab significantly reduced the proportion of participants who had one or more exacerbations from 48.8 to 30.3% (P<0.001). Improvements occurred with omalizumab despite reductions in the use of inhaled glucocorticoids and long-acting beta-agonists.

CONCLUSIONS

When added to a regimen of guidelines-based therapy for inner-city children, adolescents, and young adults, omalizumab further improved asthma control, nearly eliminated seasonal peaks in exacerbations, and reduced the need for other medications to control asthma. (Funded by the National Institute of Allergy and Infectious Diseases and Novartis; ClinicalTrials.gov number, NCT00377572.).

Safety of omalizumab in asthma

INTRODUCTION

Omalizumab is the first mAb to be introduced for the management of asthma. It is also the first agent designed to block the effects of IgE in initiating the allergic cascade resulting in asthma manifestations. Introduced in 2003, it is now widely used as an effective therapeutic tool in moderate-to-severe allergic asthmatics who are uncontrolled on maximal conventional therapy, including high-dose inhaled steroids and long-acting β-agonists. There is still understandable concern regarding the long-term effects of this drug.

AREAS COVERED

The authors provide a review of safety data generated by controlled clinical trials and post-marketing surveillance as well as a brief overview of the clinical indications and efficacy of omalizumab. They also address specific issues of concern, including the risk of anaphylaxis and malignancy. The reader will gain a working knowledge of the role of omalizumab in current guidelines for the management of asthma.

EXPERT OPINION

Omalizumab appears to be safe and well-tolerated. The possible association of malignancy with omalizumab has been of the greatest concern to patients and physicians. Analysis of clinical study data shows that this incidence is rare and the relative risk of cancer with omalizumab is not significantly different from that which is expected in the general population of people with asthma. As part of a relatively new class of agents, continued surveillance is needed as its indications expand and its use in the population continues to grow.

The role of monoclonal antibodies in the treatment of severe asthma

A number of therapeutic agents are available for the treatment of asthma, including inhaled corticosteroids, long- and short-acting beta-agonists, leukotriene-modifying agents, long- and short-acting anticholinergic agents, chromones, theophylline, allergen immunotherapy, and oral corticosteroid therapy. All available therapies, despite their proven efficacy, are purely symptomatic including the topical steroids. This issue has led to the development of several biologic agents to aid in asthma management and to potentially alter the course of the disease by interfering with specific aspects of inflammation which may modify remodeling in the airways. Monoclonal antibodies have offered a class of therapeutic agents that enhance treatment options for patients with moderate-to-severe persistent asthma. As such, this article provides an overview of present and future monoclonal antibody therapies for the treatment of patients with severe asthma.

Effectiveness of omalizumab in reducing corticosteroid burden in patients with moderate to severe persistent allergic asthma

BACKGROUND

Asthma guidelines advocate maintaining asthma control while minimizing corticosteroid exposure.

OBJECTIVE

To assess the reduction in corticosteroid burden during long-term treatment and the corresponding impact of this reduction on asthma control, lung function, and inflammation in patients with moderate to severe allergic asthma.

METHODS

We conducted a pooled analysis (N = 1,071) of 2 similarly designed, randomized, double-blind, placebo-controlled omalizumab trials and their extension phases. Each study included a 16-week steroid-stable phase, a 12-week steroid-reduction phase, and a 24-week extension phase. Patients received subcutaneous omalizumab (minimum, 0.016 mg/kg/IU (IgE/mL) every 4 weeks) or placebo every 2 or 4 weeks. Outcomes included change from baseline in inhaled corticosteroid dose, number of oral corticosteroid bursts, and other clinical measures, including asthma exacerbations and change in asthma quality-of-life score (questionnaire), lung function, and eosinophil count.

RESULTS

The median reduction from baseline in inhaled corticosteroid dose (beclomethasone dipropionate equivalent dose) by the completion of the extension phase was greater for the omalizumab group than for the placebo group (-420.0 vs -252.0 μg/d; P < .001). During that time, omalizumab-treated patients required fewer oral corticosteroid bursts overall for treatment of acute exacerbations (mean, 0.2 vs 0.3; relative risk, 0.56; 95% confidence interval, 0.41 to 0.76; P < .001) and demonstrated greater improvements in measures of asthma control.

CONCLUSION

The addition of omalizumab to baseline therapy in patients 12 years or older with moderate to severe persistent allergic asthma resulted in a durable reduction in the overall steroid burden and improvement in other clinical measures of asthma control.

Effectiveness of omalizumab in patients 50 years and older with severe persistent allergic asthma

BACKGROUND

Omalizumab is approved for the treatment of severe allergic asthma.

OBJECTIVES

To compare the efficacy of omalizumab therapy in patients 50 years or older with patients younger than 50 years.

METHODS

Between November 2005 and November 2007 a total of 174 asthma patients 50 years or older (40.7% male, 51.1% taking oral corticosteroids, and mean [SD] serum IgE level of 315 [353] U/L) and 297 asthma patients younger than 50 years (40.0% male, 50.5% taking oral corticosteroids, and mean [SD] serum IgE level of 363 [431] U/L) who met the European Union criteria for add-on therapy with anti-IgE were treated prospectively with omalizumab for 4 months as part of 2 postmarketing surveillance trials.

RESULTS

Compared with the pretrial period omalizumab treatment reduced the rate of severe exacerbations in patients 50 years or older by 68.9% (P < .001) and in patients younger than 50 years by 75.4% (P < .001). After 4 months there was a marked reduction of daily asthma symptoms and nocturnal awakenings by 67.8% and 72.6% in the older and by 79.3% and 82.5% in the younger patients, respectively (P < .001, all 4 comparisons). In 60% of patients 50 years or older lung function improved compared with 69% of patients younger than 50 years. Efficacy of omalizumab was rated as excellent or good by most physicians in patients 50 years or older (68.4%) and younger than 50 years (76.8%, P = .05 elderly vs younger). Adverse events were reported in 35.5% of patients 50 years or older and 32.1% of patients younger than 50 years. There was a higher rate of discontinuation of omalizumab therapy in older patients (20.9% vs 11.1%, P = .006).

CONCLUSIONS

The present study confirms the clinical efficacy of omalizumab in patients with severe allergic asthma irrespective of age in a real-life setting outside the omalizumab trial program.

High-affinity immunoglobulin E receptor expression is increased in large and small airways in fatal asthma

BACKGROUND

IgE and its high-affinity receptor FcɛRI play an important role in allergy and asthma. The distribution of FcɛRI expression in the airways and within the airway wall, however, is largely unknown.

OBJECTIVE

In this study, we aimed to map the distribution of FcɛRI in different layers of large airways (LA) and small airways (SA) in lung tissue from non-smoking and smoking patients who died of asthma [fatal asthma (FA)] and non-smoking controls (CTR).

METHODS

Postmortem lung tissue from 24 cases of non-smoking FA, 13 smoking FA patients and from 19 subjects who died of non-pulmonary causes (CTR) was immunohistochemically stained for FcɛRI and AA1 (mast cell tryptase marker). The expression of these markers was analysed in inner, muscle, and outer layers of both LA and SA by image analysis.

RESULTS

FcɛRI expression was higher in non-smoking and smoking FA compared with CTR in the inner and outer layer of SA. In the outer layer of LA, FcɛRI expression was higher in non-smoking FA compared with CTR. AA1 was higher in non-smoking FA compared with smoking FA and CTR in the outer layer of the SA, which was correlated with FcɛRI in this layer.

CONCLUSION

Our results show that the expression of FcɛRI is higher in both LA and SA in FA compared with CTR. These differences are predominantly found in the outer layer where they can be attributed in part to the increased mast cell numbers. These results indicate an increased capacity to mount IgE-mediated reactions in FA, both in LA and SA.