Experience with monoclonal antibodies in allergic mediated disease: seasonal allergic rhinitis

Allergic rhinitis: current options and future perspectives

PURPOSE OF REVIEW

Allergic rhinitis due its high prevalence and burden needs to be properly treated. The disease's clinical features impose well tolerated drugs usable for long-term treatment. Nowadays, second-generation antihistamines and inhaled steroids represent the milestone of rhinitis therapy. The aim of the present review is to provide an update on allergic rhinitis treatment. A particular attention has been deserved to clinical trials, published in the last year that assess the efficacy and safety of new formulation of available drugs or new molecules.

RECENT FINDINGS

Available and new drugs under investigation seem able to control rhinitis symptoms without a significant patient's burden. The challenge for the next years will be to improve treatment adherence rather than to introduce new drugs.

SUMMARY

Allergic Rhinitis and its Impact on Asthma guidelines have brought attention to allergic rhinitis and its impact on asthma, but have also proposed a new classification in terms of symptoms severity and persistence useful for tailoring treatment on patients' phenotypes. Their further dissemination is needed; furthermore, they represent a cornerstone for the scientific community through a continuous update on relevant issues such as rhinitis phenotypes, disease management on the basis of new treatments, clinical trials transferability in real life, and allergic rhinitis management in public health programs.

New therapies for allergic rhinitis

Because of its burden on patient's lives and its impact on asthma, allergic rhinitis must be treated properly with more effective and safer treatments. According to guidelines by Allergic Rhinitis and Its Impact on Asthma (ARIA), the classification, pathogenesis, and treatment of allergic rhinitis are well defined. Currently, second-generation antihistamines and inhaled steroids are considered the cornerstone of first-line therapy. However, new formulations of available drugs (e.g., loratadine and rupatadine oral solution, ebastine fast-dissolving tablets, and the combination of intranasal fluticasone propionate and azelastine hydrochloride), recently discovered molecules (e.g., ciclesonide, bilastine, and phosphodiesterase-4 inhibitors), immunologic targets (e.g., omalizumab), and unconventional treatments (e.g., homeopathic treatments) are currently under investigation and represent a new frontier in modern medicine and in allergic rhinitis management. The aim of this review is to provide an update on allergic rhinitis treatment, paying particular attention to clinical trials published within the past 20 months that assessed the efficacy and safety of new formulations of available drugs or new molecules.

Development of assay for determining free IgE levels in serum from patients treated with omalizumab

BACKGROUND

Omalizumab, a monoclonal anti-IgE antibody, is currently indicated for the treatment of moderate-to-severe allergic asthma. To measure active IgE levels in sera from patients treated with omalizumab, the IgE subfraction in complex with omalizumab should be eliminated from total IgE, and free IgE levels can then be determined. With the aim of therapeutic monitoring for anti-IgE therapy, we developed a new ELISA for free IgE.

METHODS

We used recombinant human soluble FcεRIα as a capture antigen and a biotinylated polyclonal anti-IgE antibody for detection. Using the newly developed ELISA, we measured the serum free IgE levels weekly in four asthmatic patients after their first omalizumab injection. We also measured the serum free IgE levels in 54 patients treated with omalizumab for over 4 weeks.

RESULTS

This assay was technically robust, the mean recovery rate in serum was 93.16% ± 5.34%. For all patients, omalizumab treatment significantly reduced serum free IgE levels prior to the second omalizumab injection. To maintain the benefit of omalizumab, serum free IgE concentrations should be <50 ng/ml. However, in 14 of 54 patients treated with omalizumab for over 4 weeks, serum free IgE concentrations measured by our ELISA were >50 ng/ml.

CONCLUSIONS

Our data suggest that the measurement of free IgE levels using our newly developed ELISA would be useful for monitoring serum free IgE levels during omalizumab therapy.

Severe asthma and the omalizumab option

Atopic diseases and asthma are increasing at a remarkable rate on a global scale. It is now well recognized that asthma is a chronic inflammatory disease of the airways. The inflammatory process in many patients is driven by an immunoglobulin E (IgE)-dependent process. Mast cell activation and release of mediators, in response to allergen and IgE, results in a cascade response, culminating in B lymphocyte, T lymphocyte, eosinophil, fibroblast, smooth muscle cell and endothelial activation. This complex cellular interaction, release of cytokines, chemokines and growth factors and inflammatory remodeling of the airways leads to chronic asthma. A subset of patients develops severe airway disease which can be extremely morbid and even fatal. While many treatments are available for asthma, it is still a chronic and incurable disease, characterized by exacerbation, hospitalizations and associated adverse effects of medications. Omalizumab is a new option for chronic asthma that acts by binding to and inhibiting the effects of IgE, thereby interfering with one aspect of the asthma cascade reviewed earlier. This is a humanized monoclonal antibody against IgE that has been shown to have many beneficial effects in asthma. Use of omalizumab may be influenced by the cost of the medication and some reported adverse effects including the rare possibility of anaphylaxis. When used in selected cases and carefully, omalizumab provides a very important tool in disease management. It has been shown to have additional effects in urticaria, angioedema, latex allergy and food allergy, but the data is limited and the indications far from clear. In addition to decreasing exacerbations, it has a steroid sparing role and hence may decrease adverse effects in some patients on high-dose glucocorticoids. Studies have shown improvement in quality of life measures in asthma following the administration of omalizumab, but the effects on pulmonary function are surprisingly small, suggesting a disconnect between pulmonary function, exacerbations and quality of life. Anaphylaxis may occur rarely with this agent and appropriate precautions have been recommended by the Food and Drug Administration (FDA). As currently practiced and as suggested by the new asthma guidelines, this biological agent is indicated in moderate or severe persistent allergic asthma (steps 5 and 6).

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.

Omalizumab in asthma: approval and postapproval experience

Omalizumab is a humanized mouse monoclonal antibody that binds specifically to the constant region of the immunoglobulin (Ig)E heavy chain. Omalizumab exerts its effects by reducing free serum IgE levels and FcepsilonRI expression on several cell types. These effects have been shown to result in decreased airway inflammation and clinical improvement. In multiple studies, omalizumab has been shown to be efficacious in the treatment of moderate-to-severe persistent asthma and is currently approved by the US Food and Drug Administration for the treatment of moderate-to-severe allergic asthma in patients age 12 yr and older. Moreover, omalizumab has been demonstrated to be effective in the treatment of children and adults with seasonal and perennial allergic rhinitis. Postmarketing surveillance has shown omalizumab to be a relatively safe and well-tolerated medication.

Anti-IgE therapy in allergic disease

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Omalizumab and the treatment of allergic rhinitis

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

Etiopathogenesis and Management of Perennial Allergic Rhinitis

Perennial allergic rhinitis is an inflammatory disorder characterized by symptoms of nasal congestion, rhinorrhea, sneezing, and itching. The prevalence of allergic rhinitis is quite common and affects 20% or more of various populations. Some patients with allergic rhinitis are symptomatic only during the pollen season, while many others are allergic to multiple allergens including indoor allergens such as house dust mites, animal dander, cockroaches, and fungi, which lead to perennial symptoms. Immunoglobulin (Ig)-E is the proximate cause of perennial allergic rhinitis. Circulating IgE antibodies bind to the high affinity IgE receptor on mast cells and basophils. IgE antibodies, bound to the receptors crosslinked by allergen, initiate the secretion of inflammatory mediators including histamine, leukotrienes, and cytokines. These mediators can induce both acute and chronic changes that result in symptoms of allergy. Many therapies are approved for the treatment of allergic rhinitis including intranasal corticosteroids, antihistamines with or without decongestants, and nasal cromolyn sodium (sodium cromoglicate). Allergen avoidance is the mainstay of therapy for many patients but is not always practical. For those patients who have not responded to appropriate medications, allergen specific immunotherapy may also be effective.A number of studies with omalizumab have shown that it is effective in the treatment of seasonal allergic rhinitis induced by pollen such as ragweed and birch pollen. Omalizumab is a molecularly cloned humanized monoclonal antibody inhibiting human IgE. It binds specifically to the region of the IgE molecule that binds to the IgE receptor on the mast cell or basophils. Because omalizumab cannot bind IgE molecules that are already bound to the surface receptors on mast cells and basophils, it does not stimulate secretion of mediators from these cells. Omalizumab does not appear to stimulate an immune response against itself. It rapidly reduces free serum IgE levels by over 95% when administered at therapeutic doses and also results in the reduction of IgE receptors on mast cells and basophils. The combined effects of reduction of both free IgE in serum and the receptor density on the mast cells or basophils results in decreased allergen-stimulated mediator release. Preliminary studies in the treatment of perennial allergic rhinitis supports omalizumab's efficacy and safety. The compound has been well tolerated. Aside from urticarial reactions, adverse effects appear to be minimal. Omalizumab is the first of several new immune-based specifically targeted molecules that may prove to be extremely valuable in the treatment of perennial allergic rhinitis, as it is often unresponsive to traditional therapies.

Asthma and rhinosinusitis

Allergic rhinoconjunctivitis and asthma are becoming more common in industrialized societies, particularly in the second and third decades of life, when those affected are at a vital stage of their education and career. It is therefore of paramount importance that the treatment options available be effective, improve quality of life, and above all, they must be without any significant unwanted effects. National and international guidelines for the treatment of both allergic rhinitis and asthma have been released recently that put forward recommendations based on an extensive evidence-based review of the literature for the care of these diseases that would meet these goals of disease management.

Omalizumab treatment downregulates dendritic cell FcεRI expression

BACKGROUND

Dendritic cells (DCs) are potent antigen-presenting cells that express FcepsilonRI, the high-affinity IgE receptor. Although the downregulation of basophil FcepsilonRI during anti-IgE therapy with omalizumab is well documented, its effect on FcepsilonRI expression by DCs has not been reported.

OBJECTIVE

We hypothesized that IgE regulates surface FcepsilonRI expression by DCs in vivo and that, consequently, anti-IgE therapy decreases FcepsilonRI expression by DCs.

METHODS

In a randomized, double-blind, placebo-controlled clinical trial 24 subjects (16 receiving omalizumab and 8 receiving placebo) with seasonal allergic rhinitis received the study drug on days 0 and 28. Serial blood samples drawn on days 0, 7, 14, 28, and 42 were analyzed for precursor DC1 (pDC1) and pDC2 surface expression of FcepsilonRIalpha by using flow cytometry.

RESULTS

Omalizumab caused a significant decrease in surface FcepsilonRI expression at all time points examined in both the pDC1 and pDC2 subsets. No significant change was seen with placebo. The maximum decrease in FcepsilonRI expression in the omalizumab group was 52% and 83%, respectively, for the pDC1 and pDC2 subsets. The decrease in FcepsilonRI expression by both pDC subsets correlated with the decrease in serum-free IgE and was of a similar magnitude to that found in basophils. A 10-fold decrease in IgE corresponded to a 42% and 54% decrease in surface FcepsilonRI expression by the pDC1 and pDC2 subsets, respectively.

CONCLUSION

These results demonstrate that anti-IgE therapy causes a rapid decrease in DC surface FcepsilonRI expression and establish that IgE is an important regulator of FcepsilonRI expression by DCs.

The use of anti-IgE in the treatment of allergic asthma

Allergic sensitization plays a significant role in the development of asthma in many patients. IgE-mediated immune responses play a central role in the pathogenesis of this condition. The development of a treatment that interrupts this pathway is particularly desirable to prevent downstream events. Large-scale trials in patients ranging in age from 6 to 76 years have shown that omalizumab therapy is safe and effective in the treatment of severe allergic asthma. This is particularly true in patients who experience poor disease control despite high doses of inhaled steroids or need oral steroids for control of their disease. These patients are at risk for severe exacerbations despite recommended therapy, and anti-IgE therapy has proved to reduce these episodes. Early aggressive therapy of asthma is needed for maximum control in all age groups. Despite the efficacy of inhaled steroids there is a reluctance to use these agents, especially in younger children. Because of these concerns a long-acting treatment is especially desirable. Because of imperfect effort or technique limiting inhaled medications, introduction of an effective agent that could be administered parenterally at long intervals also is very important. Allergic rhinitis is a co-existing problem in many patients with allergic asthma. Immunotherapy trials have suggested that early intervention with immunotherapy and allergic rhinitis patients may actually prevent the development of asthma. Early treatment of patients with anti-IgE may also have benefits, particularly in those who have concomitant allergic rhinitis in addition to allergic asthma. Although omalizumab has not yet received Food and Drug Administration approval in the United States, it shows great promise in the management of patients requiring high doses of inhaled or oral corticosteroids for control of their disease and to prevent exacerbations of asthma in such patients. Reductions in high doses of inhaled or oral corticosteroids may prevent long-term complications of these treatments.

Upper airway disorders and asthma: a syndrome of airway inflammation

OBJECTIVE

This article presents recent evidence of an upper and lower airway link. After reading this article, readers should have an understanding of the evidence for the pathologic relationship between asthma and upper airway disorders such as rhinosinusitis and allergic rhinitis.

DATA SOURCES

Epidemiologic, pathophysiologic, and treatment outcomes studies were used. Only literature in the English language was reviewed.

STUDY SELECTION

Material was taken from academic/scholarly journals.

RESULTS

Epidemiologic data indicate that asthma and allergic rhinitis frequently coexist, with rhinitis symptoms reported among 19 to 94% of asthma patients, and asthma reported among 19 to 38% of those with allergic rhinitis. Allergic rhinitis often precedes asthma symptomatology and has been shown to be a risk factor for the development of asthma. The severity of one's allergic rhinitis also has been shown to be directly correlated with asthma severity. Patients with allergic rhinitis exhibit increased eosinophil activity in both upper and lower airways. In these patients, nasal allergen challenge can induce increased bronchial hyperresponsiveness, suggesting that upper and lower airway disorders share common inflammatory features. Treatment of rhinitis symptoms has been shown to produce better asthma symptom control and, in a few studies, the improvement of airway function in patients with concomitant asthma.

CONCLUSIONS

Evidence suggests that upper respiratory disorders such as allergic rhinitis and rhinosinusitis are different facets of a larger systemic inflammatory syndrome involving both the upper and lower airways. Several important questions remain to be answered before the nature of the relationship between lower and upper airway disorders is fully understood.

Omalizumab. A review of the new treatment of allergic asthma and seasonal allergic rhinitis

The causal role of immunoglobulin E (IgE) in triggering the cascade of biochemical events leading to allergic disease is well established. Treatments that selectively inhibit IgE activity are a logical approach in managing the allergic response. Omalizumab is a recombinant humanised monoclonal antibody which specifically binds to the Cε3 domain of immunoglobulin (Ig) E, the site of high-affinity IgE receptor binding. The clinical benefit and steroid-sparing effect of treatment with the anti-immunoglobulin-E (IgE) antibody, Omalizumab, was assessed in patients with moderate-to-severe allergic asthma and seasonal allergic rhinitis. Intravenous and subcutaneous administration of anti-IgE mAb reduces circulating levels of IgE in atopic patients to low levels commonly seen in non-atopic individuals. Anti-IgE therapy offers protection against allergen-induced bronchoconstriction, reduces the need for short acting inhaled beta 2-agonist and corticosteroids among asthmatic patients and reduces severity of symptoms of allergic rhinitis. Adverse events were infrequent in clinical trials of omalizumab, and not significantly different from placebo. The most frequent drug-related event was mild to moderate urticaria. They do not induce anaphylaxis and the occurrence of antibodies against anti-IgE mAb is sporadic. The results of cited studies suggest that humanized anti-IgE monoclonal antibodies may have important immunotherapeutic benefit for treatment of allergic disorders.