Omalizumab in Japanese children with severe allergic asthma uncontrolled with standard therapy

Biological treatments in childhood asthma

PURPOSE OF REVIEW

The aim is to update the information currently available for the use of biologics in severe asthma in children, in order to facilitate their prescription as far as possible.

RECENT FINDINGS

The appearance of biologics for the treatment of severe asthma has meant a revolutionary change in the therapeutic approach to this disease. Currently, five biologics have been approved for severe asthma in children and/or adolescents by the regulatory agencies: omalizumab, mepolizumab, benralizumab, dupilumab and tezepelumab. But despite their positive results in terms of efficacy, there are still relevant points of debate that should induce caution when selecting the most appropriate biologic in a child with severe asthma. Indeed, safety is essential and, for several of the existing treatments, the availability of medium-term to long-term data in this regard is scarce.

SUMMARY

The use of biologics can facilitate the therapeutic paradigm shift from pleiotropic treatments to personalized medicine. However, the choice of the most appropriate biologics remains a pending issue. On the other hand, to the extent that several of the biologics have been available for a relatively short time, the most robust evidence in terms of efficacy and safety in children is that of omalizumab.

Early Assessment of Efficacy and Safety of Biologics in Pediatric Allergic Diseases: Preliminary Results from a Prospective Real-World Study

BACKGROUND

Despite the increasing interest in biologics for the management of allergic diseases, sparse real-world data are still available in the pediatric population. This study aimed to evaluate the early real-life efficacy and safety of omalizumab for patients with moderate-to-severe asthma and chronic spontaneous urticaria (CSU), and Dupilumab for patients with moderate-to-severe atopic dermatitis (AD).

METHODS

A prospective study enrolling children aged 6-18 years was designed to assess the efficacy and safety of biologic drugs at 16 weeks of treatment (T1). The effectiveness was measured using validated questionnaires (ACQ-5 for asthma, UAS7 for CSU, and EASI score for AD). Secondary outcome measures included reductions in inhaled corticosteroid (ICS) dosages, asthma-related hospitalizations/exacerbations, and quality of life (QoL) indicators (iNRS, sNRS, DLQI/cDLQI) for CSU and AD. Safety was expressed according to the descriptions of adverse events provided by EMA and FDA.

RESULTS

The study cohort consisted of eighteen children (mean age 12.9 ± 3.4 years). The omalizumab treatment significantly reduced ACQ-5 and UAS7 scores (p = 0.002 and p < 0.001, respectively). In patients with asthma, decreased ICS dosage and hospitalization/exacerbation rates were observed. QoL parameters significantly improved in CSU and AD patients. No severe adverse events were reported for either treatment.

CONCLUSIONS

Our findings validate omalizumab and dupilumab as effective and safe therapeutic options for managing moderate-to-severe allergic diseases in children and adolescents.

Long-Term Safety of Omalizumab in Children with Asthma and/or Chronic Spontaneous Urticaria: A 4-Year Prospective Study in Real Life

Background: Insufficient data are available on the long-term "real-life" safety profile of omalizumab in children. This study evaluated the long-term safety of omalizumab in a pediatric cohort with severe asthma or chronic spontaneous urticaria (CSU). Methods: A monocentric, prospective study evaluated the long-term safety of omalizumab in patients aged 6-18 years. Each patient completed the standardized MedDRA questionnaire to identify adverse events (AEs). Results: In total, 23 patients, median age 15 (14-18) years, affected by severe asthma (60.8%) or CSU (39.2%), treated with omalizumab for 2 (1-4) years were enrolled. The most common AEs belong to the system organ class (SOC) of general disorders and administration-site conditions (37.17%). Skin and subcutaneous tissue problems represent the second most frequently reported AEs (24.35%). Central nervous system and musculoskeletal disorders were quite frequent (15.38% and 8.97%, respectively). Other adverse events were tachycardia (5.12%), vertigo and abdominal pain (2.60% and 3.86%, respectively), and dry eye (1.3%). Only one patient reported herpes virus infection during treatment (1.3%). No cases of anaphylaxis, hemopathies, uronephropathies, respiratory, psychiatric, hepatobiliary, or oncological pathologies were reported. Conclusions: Long-term "real-life" treatment with omalizumab in children appears well tolerated. Its safety and efficacy profile makes omalizumab an excellent alternative in severe asthma and CSU in children.

Omalizumab: An Optimal Choice for Patients with Severe Allergic Asthma

Omalizumab is the first monoclonal antibody that was globally approved as a personalized treatment option for patients with moderate-to-severe allergic asthma. This review summarizes the knowledge of almost two decades of use of omalizumab to answer some important everyday clinical practice questions, concerning its efficacy and safety and its association with other asthma-related and drug-related parameters. Evidence suggests that omalizumab improves asthma control and reduces the incidence and frequency of exacerbations in patients with severe allergic asthma. Omalizumab is also effective in those patients in reducing corticosteroid use and healthcare utilization, while it also seems to improve lung function. Several biomarkers have been recognized in predicting its efficacy in its target group of patients, while the optimal duration for evaluating its efficacy is between 16 and 32 weeks.

Severe pediatric asthma with a poor response to omalizumab: a report of three cases and three-dimensional bronchial wall analysis

Omalizumab is used for the treatment of persistent severe allergic asthma in adults and children. However, some patients remain symptomatic even after omalizumab treatment. In bronchial asthma, chronic inflammation of the bronchial wall causes thickening of the airway wall, resulting from irreversible airway remodeling. Progression of airway remodeling causes airflow obstruction, leading to treatment resistance. We report three Japanese children with severe asthma who had a poor response to omalizumab treatment. They had a long period of inadequate management of asthma before initiating omalizumab. Even after omalizumab treatment, their symptoms persisted, and the parameters of spirometry tests did not improve. We hypothesized that omalizumab was less effective in these patients because airway wall remodeling had already progressed. We retrospectively evaluated the bronchial wall thickness using a three-dimensional bronchial wall analysis with chest computed tomography. The bronchial wall thickness was increased in these cases compared with six responders. Progressed airway wall thickness caused by airway remodeling may be associated with a poor response to omalizumab in children with severe asthma.

Clinical Experience with Anti-IgE Monoclonal Antibody (Omalizumab) in Pediatric Severe Allergic Asthma-A Romanian Perspective

Background: Asthma is the most common chronic disease affecting children, with a negative impact on their quality of life. Asthma is often associated with comorbid allergic diseases, and its severity may be modulated by immunoglobulin E (IgE)-mediated allergen sensitization. Omalizumab is a humanized monoclonal anti-IgE antibody, the first biological therapy approved to treat patients aged ≥6 years with severe allergic asthma. The primary objective of our study was to investigate the efficacy and safety of Omalizumab in Romanian children with severe allergic asthma. Methods: In this observational real-life study, 12 children and adolescents aged 6 to 18 years (mean 12.4 years) with severe allergic asthma received Omalizumab as an add-on treatment. Asthma control, exacerbations, lung function, and adverse events were evaluated at baseline and after the first year of treatment. Results: We observed general improvement in total asthma symptom scores and reduction in the rate of exacerbation of severe asthma. Omalizumab treatment was associated with improvement in the measures of lung function, and no serious adverse reactions were reported. FEV1 improved significantly after one year of treatment with Omalizumab [ΔFEV1 (% pred.) = 18.3], and [similarly, ΔMEF50 (%) = 25.8]. The mean severe exacerbation rate of asthma decreased from 4.1 ± 2.8 to 1.15 ± 0.78 (p < 0.0001) during the year of treatment with Omalizumab. Conclusions: This study showed that Omalizumab can be an effective and safe therapeutic option for Romanian children and adolescents with severe allergic asthma, providing clinically relevant information on asthma control and exacerbation rate in children and adolescents. The results demonstrated the positive effect of Omalizumab in young patients with asthma, starting from the first year of treatment.

Effectiveness and Safety Studies of Omalizumab in Children and Adolescents With Moderate-To-Severe Asthma

BACKGROUND

Omalizumab is currently approved for the treatment of moderate-to-severe allergic asthma in patients 6 years and older.

OBJECTIVE

To assess the effectiveness and safety of subcutaneous omalizumab as an add-on therapy option for moderate-severe allergic asthma in patients aged 6-20 years old.

METHODS

The studies published from July, 1970 to May, 2021 were searched from the electronic databases which followed keywords: ("anti-IgE" OR "anti-immunoglobulin E" OR "anti-IgE antibody" OR "omalizumab" OR "rhuMAb-E25" OR "Xolair") AND "asthma" AND ("child" OR "children" OR "adolescents" OR "youth" OR "teenager" OR "kids" OR "pediatric"). Thirteen studies were pooled to determine the effectiveness and safety of omalizumab. Efficacy endpoints were evaluated using a fixed-effects model or a random-effects model depending on heterogeneity. Safety endpoints were evaluated by odds ratio.

RESULTS

Thirteen studies were included. In this meta-analysis, our results showed that fractional exhaled nitric oxide and asthma control test scores were significantly improved with omalizumab treatment. Serum immunoglobulin E was also decreased in children with moderate-to-severe asthma after treatment with omalizumab. The analysis found that there was no significant difference between pre-and post-treatment in forced expiratory volume in one second/ forced vital capacity ratio, forced expiratory flow between 25 and 75% of vital capacity, or FEV1. Overall, more adverse events occurred with omalizumab compared to placebo. However, the degree was mild to moderate.

CONCLUSION

This meta-analysis indicates that omalizumab is safe and effective to treat children and adolescents with moderate-to-severe asthma.

Real-life long-term safety and effectiveness of omalizumab in Japanese pediatric patients with severe allergic asthma: A post-marketing surveillance

BACKGROUND

Omalizumab is approved as add-on therapy for pediatric asthma since 2013 in Japan, however, its data in clinical practice is limited. This post-marketing surveillance aimed to evaluate long-term safety and effectiveness of omalizumab in Japanese pediatric patients with severe allergic asthma in real-life setting.

METHODS

This 104-week, multicenter surveillance was conducted from September 2013 to May 2019 by central registration method. Patients with severe allergic asthma aged ≥6 and < 15 years at initiation of treatment who were first-time omalizumab users were included. The primary endpoints included incidence of adverse drug reactions and physician's Global Evaluation of Treatment Effectiveness (GETE). The secondary endpoints included incidence of serious adverse events, adverse events and adverse drug reactions of special interest and asthma exacerbation-related events.

RESULTS

Of the 128 patients enrolled, 127 completed the surveillance and were included for safety and effectiveness analysis. Thirteen patients experienced 20 adverse drug reactions with an incidence rate of 10.2%. The most frequent adverse drug reactions were pyrexia (2.4%) and urticaria (1.6%). In total, adverse events and serious adverse events occurred in 60 (47.2%) and 30 patients (23.6%) respectively. Two patients experienced anaphylactic reaction and 1 patient experienced type 1 hypersensitivity. 77.2% had an effective response to omalizumab according to GETE at final assessment, and frequency of all asthma exacerbation-related events decreased in post-treatment versus pre-treatment.

CONCLUSIONS

Long-term omalizumab treatment showed no new safety signals in pediatric patients with severe allergic asthma. The observed safety and effectiveness profile was consistent with previous studies.

The Long-Term Effectiveness of Omalizumab in Adult Patients with Severe Allergic Asthma: Continuous Treatment Versus Boosting Treatment

The implications of boosting Omalizumab treatment (OT) in patients with severe allergic asthma (SAA) remain unclear. The study aimed to explore and compare the 12-month effectiveness between continuous, at least 10-month OT (continuation group) and four-month boost of Omalizumab (boost group) in adult patients with SAA. In this retrospective cohort study, clinical data were collected for further analysis. Of all participants (n = 124), a significant reduction in annual exacerbations (baseline = 0.8 ± 1.5, follow-up = 0.5 ± 1.0, p = 0.047 *) and improvement in small airway ventilation as evaluated by forced expiratory flow at 25–75% (baseline = 55.1 ± 11.1%, follow-up = 59.4 ± 8.4%, p < 0.001 *) were found in the continuation group (n = 110). By contrast, the boost group (n = 14) had significantly increased annual exacerbations (baseline = 0.7 ± 1.4, follow-up = 2.9 ± 3.6, p = 0.031 *) and impaired small airway function (baseline = 55.3 ± 12.9, follow-up = 52.1 ± 12.5, p = 0.026 *). Furthermore, the continuation group rather than the boost group had significant decreases in the frequency of oral corticosteroid (OCS) use as controllers (baseline = 32.7%, follow-up = 20.0%, p = 0.047 *; baseline = 50.0%, follow-up = 21.4%, p = 0.237, respectively) and OCS maintenance dose (mg/month) (baseline = 85.9 ± 180.8, follow-up = 45.8 ± 106.6, p = 0.020 *; baseline = 171.4 ± 221.5, follow-up = 50.0 ± 104.3, p = 0.064, respectively), and increases in asthma control test scores (baseline = 16.0 ± 3.0, follow-up = 19.8 ± 4.4, p < 0.001 *; baseline = 14.6 ± 3.8, follow-up = 19.7 ± 4.7, p = 0.050, respectively). Continuous OT would be beneficial for adult patients with SAA, while boost of Omalizumab would worsen their long-term outcomes.

Real-World Effectiveness of Omalizumab in Severe Allergic Asthma: A Meta-Analysis of Observational Studies

BACKGROUND

Assessment of clinical outcomes in the real-world corroborates findings from randomized controlled trials (RCTs).

OBJECTIVE

This meta-analysis evaluated real-world data of omalizumab on treatment response, lung function, exacerbations, oral corticosteroid (OCS) use, patient-reported outcomes (PROs), health care resource utilization (HCRU), and school/work absenteeism at 4, 6, and 12 months after treatment.

METHODS

Observational studies in patients with severe allergic asthma (≥6 years) treated with omalizumab for ≥16 weeks, published from January 2005 to October 2018, were retrieved from PubMed, Embase, and Cochrane. A random-effects model was used to assess heterogeneity.

RESULTS

In total, 86 publications were included. Global evaluation of treatment effectiveness (GETE) was good/excellent in 77% patients at 16 weeks (risk difference: 0.77; 95% confidence interval [CI]: 0.70-0.84; I² = 96%) and in 82% patients at 12 months (0.82, 0.73-0.91; 97%). The mean improvement in forced expiratory volume in 1 second was 160, 220, and 250 mL at 16 weeks, 6 months, and 12 months, respectively. There was a decrease in Asthma Control Questionnaire score at 16 weeks (-1.14), 6 months (-1.56), and 12 months (-1.13) after omalizumab therapy. Omalizumab significantly reduced annualized rate of severe exacerbations (risk ratio [RR]: 0.41, 95% CI: 0.30-0.56; I² = 96%), proportion of patients receiving OCS (RR: 0.59, 95% CI: 0.47-0.75; I² = 96%), and number of unscheduled physician visits (mean difference: -2.34, 95% CI: -3.54 to -1.13; I² = 98%) at 12 months versus baseline.

CONCLUSION

The consistent improvements in GETE, lung function, and PROs, and reductions in asthma exacerbations, OCS use, and HCRU with add-on omalizumab in real-life confirm and complement the efficacy data of RCTs.

Three cases of severe adolescent asthma treated with mepolizumab: lung function trajectories

Real-world experience with mepolizumab for pediatric asthma is still limited. We report 3 patients who were treated with mepolizumab for severe adolescent asthma. Two patients, a 12-year-old boy and a 14-year-old girl, responded well to mepolizumab and showed apparent improvement in lung function from a downward trend over time before treatment. The third patient, a 16-year-old boy, whose treatment was switched from omalizumab to mepolizumab, did not have satisfactory response. The 2 successful cases had eosinophil counts of 440 and 371/μL and multiple comorbid allergic diseases including food allergies. The clinical benefit to them included elimination of both exacerbation and exercise-induced asthma. Interestingly, the boy's food-induced gastrointestinal symptoms disappeared following start of mepolizumab treatment.

Roles of omalizumab in various allergic diseases

IgE and mast cells play a pivotal role in various allergic diseases, including asthma, allergic rhinitis, and urticaria. Treatment with omalizumab, a monoclonal anti-IgE antibody, has significantly improved control of these allergic diseases and introduced a new era for the management of severe allergic conditions. About 10 years of experience with omalizumab treatment for severe allergic asthma confirmed its effectiveness and safety, reducing symptoms, frequency of reliever use, and severe exacerbations in patients with intractable conditions. Omalizumab is particularly useful in childhood asthma, where atopic conditions often determine clinical courses of asthma. Recently, omalizumab is approved for the treatment of chronic spontaneous urticaria (CSU) with the fixed dose of 300 mg. Although the mechanisms underlying the actions of omalizumab in CSU are not fully clarified, nearly 90% of patients with CSU showed a complete or a partial response to omalizumab treatment. Furthermore, omalizumab is just approved for the treatment of severe Japanese cedar pollinosis (JC) based on the successful results of an add-on study of omalizumab for inadequately controlled severe pollinosis despite antihistamines and nasal corticosteroids. For proper use of omalizumab to treat severe JC, co-administration of antihistamines is necessary, while patients should meet the criteria including strong sensitization to Japanese cedar pollen (≥class 3) and poor control under standard treatment. In the management of severe allergic diseases using omalizumab, issues including cost and concerns about relapse after its discontinuation should be overcome. At the same time, possibilities for application to other intractable allergic diseases should be considered.

'Real-life' experience in asthmatic children treated with omalizumab up to six-years follow-up

INTRODUCTION AND OBJECTIVES

Omalizumab is present in international guidelines for the control of severe asthma, but data on the long-term effects in children are limited. Our objective was to perform a 'real-life' long-term trial of omalizumab in children with allergic asthma.

MATERIALS AND METHODS

An observational single center 'real-life' study was performed. Data for treatment, lung function, side effect, asthma exacerbations and hospitalizations were recorded at six months and annually.

RESULTS

Forty-eight patients <18 years of age were enrolled. Median treatment period was 2.9 (0.5-6). Fluticasone dose for the maintenance treatment decreases significantly at six months (452mcg/day to 329.89mcg/day, respectively). This difference was maintained throughout the follow-up. Nobody used oral corticosteroid after six months. The rate of hospital admissions and visits to the emergency department for asthma exacerbations decreased significantly in the third years and fourth years follow-up, respectively. There was an improvement in lung function. Mean values of FEV₁ and FEF_25-75% before treatment were 79.88 and 62.94, respectively; after six months of treatment a statistically significant change was seen with a mean FEV₁ of 92.29 and FEF_25-75% of 76.31 (p=0.0001). Lung function values were above normal throughout the six years of treatment. No side effects were reported.

CONCLUSIONS

Overall in 'real life' omalizumab in children reduces asthma exacerbations and hospitalizations, improves lung function, and decreases the maintenance therapy. It is shown to be safe for up to six years of treatment in children.

Omalizumab and unmet needs in severe asthma and allergic comorbidities in Japanese children

Childhood asthma is one condition within a family of allergic diseases, which includes allergic rhinitis, atopic dermatitis, and food allergy, among others. Omalizumab is an anti-IgE antibody therapy that was approved in Japan for children with asthma and added to the Japanese pediatric asthma guidelines in 2017. This review highlights the Japanese clinical perspectives in pediatric allergic asthma, and consideration for allergic comorbidities, and reflects on omalizumab clinical trials in progress to present comprehensive future opportunities.

Effectiveness and safety of omalizumab in severe, persistent IgE-mediated asthma in pediatric and adult patients: a real-world observational study in Egyptian population

Objective: Real-world studies on the effectiveness of omalizumab in Egyptian population with asthma are limited. This study aimed to evaluate the real-world effectiveness and safety of omalizumab as an add-on treatment in pediatric and adult patients with severe, persistent allergic asthma in Egypt. Methods: The primary endpoint of this 16-week, prospective, open-label, multicenter, non-interventional study was the reduction in oral corticosteroid (OCS) dose. Secondary endpoints included reduction in exacerbation, improvements in quality of life and global assessment of omalizumab therapy. Results: Of the 59 patients, 53 completed the study. Add-on omalizumab significantly reduced the proportion of patients receiving OCS at Week 16 versus baseline (81.1% at baseline versus 52.8% at Week 16; p < 0.001). A 55% decrease in the total daily prednisolone-equivalent dose of OCS was observed at the end of the study compared to baseline (p < 0.001). No patients reported exacerbations or missed days from work or school after receiving omalizumab for 16 weeks compared to baseline (both p < 0.001). A statistically significant decrease was observed in asthma control questionnaire-5 scores (p < 0.001). Almost all physicians and patients rated omalizumab therapy as 'good,' 'very good' or 'excellent' in tolerability and effectiveness. No new safety signals were observed in the safety analysis of omalizumab as add-on treatment. Conclusions: Outcomes of this real-world study were consistent with previous effectiveness and safety studies of omalizumab. Omalizumab was effective and well tolerated for the management of severe, persistent IgE-mediated asthma in pediatric and adult patients in Egypt.

Cost-effectiveness of omalizumab for the treatment of inadequately controlled severe allergic asthma in Chinese children

Objective: The addition of omalizumab to standard therapy has proven to be efficacious in children with severe allergic asthma. The goal of this study was to assess the cost-effectiveness of adding omalizumab to standard treatment for asthma in Chinese pediatric patients.Methods: A Markov model was constructed to project the health and economic outcomes in pediatric patients with severe allergic asthma. Model inputs were obtained from the literature. Cost and quality-adjusted life-years (QALYs) were measured over a five-year time horizon. One-way and probabilistic sensitivity analyses were conducted.Results: For the base-case analysis, the addition of omalizumab to standard therapy yielded an incremental cost of $49,047 for 0.232 incremental QALY, led to an incremental cost-effectiveness ratio of $211,217/QALY. Sensitivity analyses were robust for these results.Conclusions: This study found that the addition of omalizumab is not a cost-effective strategy compared with standard therapy for children with severe allergic asthma in China due to its high cost.

Prospects for Monoclonal Antibody Therapy in Pediatric Asthma

PURPOSE OF REVIEW

The profile of biologic therapies for asthma is growing rapidly. We discuss how to match the proper pediatric patient with the most effective therapy.

RECENT FINDINGS

Currently available biologic therapies are most effective in patients with T2 high asthma. Newer drugs are currently being studied which target TSLP and interleukin 33. These newer drugs may provide options for asthmatics who do not respond to the current anti-IgE, anti-IL5, and anti-IL4/13 therapies. Asthma is a heterogeneous disease which can be driven by different inflammatory mediators in different patients. To select the most effective biologic therapy for a pediatric patient, the asthma phenotype must first be determined. The steep cost of biologics limits their use, which makes proper pairing of patient to therapy even more crucial. Presently, several therapies exist for T2 high asthma, but it is hoped in the future that development of drugs effective for T2 low asthmatics will be available as well.

Real-world safety and efficacy of omalizumab in patients with severe allergic asthma: A long-term post-marketing study in Japan

BACKGROUND

Omalizumab (anti-IgE monoclonal antibody) is an approved add-on therapy for Japanese patients with severe allergic asthma. As directed by the Ministry of Health, Labor and Welfare Japan, a post-marketing surveillance (PMS) study on omalizumab was conducted between 2009 and 2017.

METHODS

The PMS observed safety and efficacy of omalizumab in patients treated with open-label omalizumab for 52 weeks (with optional 2-year extension period). Primary safety outcomes included incidence and severity of adverse events (AEs) and adverse drug reactions (ADRs). Primary efficacy outcomes included physician-assessed global evaluation of treatment effectiveness (GETE). Asthma-exacerbation-related events including requirement for additional systemic steroid therapy, hospitalization, emergency room visits, unscheduled doctor visits, and absenteeism were also evaluated.

RESULTS

Of 3893 patients registered, 3620 (age [mean ± SD] 59.3 ± 16.11 years) were evaluated for 52 weeks; 44.12% were aged ≥65 years and 64.45% were women. Overall, 32.24% reported AEs and 15.30% reported serious AEs. ADRs were seen in 292 (8.07%) patients. GETE results showed that the majority of patients experienced clinical improvements (58.29% at 16 weeks and 62.40% at 52 weeks). Nearly half of all patients (47.96%) were free from asthma exacerbations after therapy. Omalizumab also reduced all events related to asthma exacerbations. No specific ADRs were observed in the elderly population.

CONCLUSIONS

This post-marketing study confirmed the clinically meaningful benefits of omalizumab in a majority of patients from Japan, and showed safety and efficacy in a real-life clinical setting to be consistent with previous reports.

Pediatric severe asthma: a case series report and perspectives on anti-IgE treatment

Background

The primary goal of asthma management is to achieve disease control for reducing the risk of future exacerbations and progressive loss of lung function. Asthma not responding to treatment may result in significant morbidity. In many children with uncontrolled symptoms, the diagnosis of asthma may be wrong or adherence to treatment may be poor. It is then crucial to distinguish these cases from the truly “severe therapy-resistant” asthmatics by a proper filtering process. Herein we report on four cases diagnosed as difficult asthma, detail the workup that resulted in the ultimate diagnosis, and provide the process that led to the prescription of omalizumab.

Case presentation

All children had been initially referred because of asthma not responding to long-term treatment with high-dose inhaled steroids, long-acting β₂-agonists and leukotriene receptor antagonists. Definitive diagnosis was severe asthma. Three out four patients were treated with omalizumab, which improved asthma control and patients’ quality of life. We reviewed the current literature on the diagnostic approach to the disease and on the comorbidities associated with difficult asthma and presented the perspectives on omalizumab treatment in children and adolescents. Based on the evidence from the literature review, we also proposed an algorithm for the diagnosis of pediatric difficult-to-treat and severe asthma.

Conclusions

The management of asthma is becoming much more patient-specific, as more and more is learned about the biology behind the development and progression of asthma. The addition of omalizumab, the first targeted biological treatment approved for asthma, has led to renewed optimism in the management of children and adolescents with atopic severe asthma.

New Drugs for Pediatric Asthma

Asthma is the most common chronic disease in children. As suggested by international guidelines, the main goals of asthma treatment are symptoms control and lung function preservation, through a stepwise and control-based approach. The first line therapy based on inhaled corticosteroids may fail to reach control in more than one third of patients, especially adolescents, and in these lung function and quality of life may progressively worsen. Treatment with omalizumab, the first anti-immunoglobulin E recombinant humanized monoclonal antibody, has been definitely approved in pediatric uncontrolled asthma. In this review, we discuss the mechanisms and potential roles of emerging therapies for pediatric severe asthma. Novel biologic drugs (i.e., dupilumab, mepolizumab, reslizumab, and benralizumab) seem to be promising in reducing annual exacerbation rates and steroid-use in glucocorticoid-dependent cases, but available data are few and limited to adolescents and adults. Evidences on the use of the muscarinic antagonist tiotropium as controller medication in pediatric settings are progressively growing, sustaining an application as asthma maintenance treatment in children aged >6 years and in preschool children with persistent asthmatic symptoms, but well powered trials are needed to confirm its safety and efficacy. New inhaled corticosteroids (i.e., ciclesonide and mometasone) are effective as once-daily controller therapy, but long-term studies in the different pediatric ages are needed to compare effectiveness and safety to usual treatments. At present, the role of macrolides in pediatric severe asthma is controversial and their administration is not recommended routinely, but may be considered in children with neutrophilic asthma for reducing daily oral steroids administration and improving lung function. Despite the availability of several novel therapeutic strategies for uncontrolled asthma, future trials targeted at specific pediatric age subgroups are needed to support evidences of safety and efficacy also in children.

Severe asthma and quality of life

Severe asthma has a great impact on the quality of life (QOL) of patients and their families. The magnitude of this morbidity is affected by several personal factors including age. Appropriate asthma control and modifications of social roles and activities are expected to improve QOL. Biologics, primarily monoclonal antibodies, have been developed to target specific pathways and molecules important in the pathogenesis of asthma. The use of biologics has shown some promising effects on the QOL of patients with severe recalcitrant asthma. Other potential measures involve targeting risk factors and comorbidities and improving the levels of adherence to therapy. This article briefly reviews the impact of severe asthma on QOL and the potential methods to combat this morbidity including the available therapeutic biologics.

Long-term safety, efficacy, pharmacokinetics and pharmacodynamics of omalizumab in children with severe uncontrolled asthma

BACKGROUND

Omalizumab is effective and well-tolerated in children with moderate to severe allergic asthma. However, the effects of long-term treatment with omalizumab in this population haven't been well investigated. The objective of this study is to evaluate the long-term safety, efficacy, pharmacokinetics and pharmacodynamics of omalizumab in children with uncontrolled severe asthma.

METHODS

Thirty-eight Japanese children (aged 7-16 years) who completed the 24-week treatment core study were included in an uncontrolled extension study, in which treatment with omalizumab continued until the pediatric indication was approved in Japan (ClinicalTrials.gov number: NCT01328886).

RESULTS

Thirty-five patients (92.1%) completed the extension study. The median exposure throughout the core and extension studies was 116.6 weeks (range, 46.9-151.1 weeks). The most common adverse events were nasopharyngitis, influenza, upper respiratory tract infection, and asthma. Serious adverse events developed in 10 patients (26.3%), but resolved completely with additional treatments. Incidence of adverse events didn't increase with extended exposure with omalizumab. Twenty-nine patients (76.3%) achieved completely- or well-controlled asthma compared with 9 patients (23.7%) at the start of the extension study. QOL scores, the rates (per year) of hospitalizations and ER visits were significantly improved compared with the baseline of the core study [39.0 vs 48.0 (median), p < 0.001 for QOL, 1.33 vs 0.16, p < 0.001 for hospitalization, 0.68 vs 0.15, p = 0.002 for ER visits]. Remarkably, the mean total IgE level showed a decreasing trend while exposure to omalizumab remained at steady-state.

CONCLUSIONS

Long-term treatment with omalizumab is well-tolerated and effective in children with uncontrolled severe allergic asthma. No new safety findings were identified.

A review of omalizumab for the management of severe asthma

Despite the expansion of the understanding in asthma pathophysiology and the continual advances in disease management, a small subgroup of patients remain partially controlled or refractory to standard treatments. Upon the identification of immunoglobulin E and other inflammatory mediators, investigations and developments of targeted agents have thrived. Omalizumab is a humanized monoclonal antibody that specifically targets the circulating immunoglobulin E, which in turn impedes and reduces subsequent releases of the proinflammatory mediators. In the past decade, omalizumab has been proven to be efficacious and well-tolerated in the treatment of moderate-to-severe asthma in both trials and real-life studies, most notably in reducing exacerbation rates and corticosteroid use. While growing evidence has demonstrated that omalizumab may be potentially beneficial in treating other allergic diseases, its indication remains confined to treating severe allergic asthma and chronic idiopathic urticaria. Future efforts may be focused on determining the optimal length of omalizumab treatment, seeking biomarkers that could better predict treatment response, as well as extending its indications.

Impact of omalizumab on medical cost of childhood asthma in Japan

Omalizumab is effective in children with severe asthma, but its impact on medical cost in Japan is not clear. We evaluated the impact of omalizumab on medical cost by comparing the pre- vs post-omalizumab-initiation medical costs of 12 children with severe asthma who received omalizumab for 2 years, and calculating incremental cost-effectiveness ratio for omalizumab therapy. Health outcome was measured as hospital-free days (HFD). The median total medical costs and medication fee per patient increased significantly after omalizumab initiation because of the high cost of omalizumab. The median hospitalization fee per patient, however, decreased significantly after omalizumab initiation due to reduction in hospitalization. Omalizumab led to an estimated increase of 40.8 HFD per omalizumab responder patient per 2 years. The cost was JPY 20 868 per additional HFD. Omalizumab can therefore reduce hospitalization cost in children with severe asthma in Japan.

Ethnic sensitivity assessment of pharmacokinetics and pharmacodynamics of omalizumab with dosing table expansion

A three-part license expansion for omalizumab (Xolair(®)), humanized anti-IgE antibody, was recently made in Japan for paediatric use, additional higher doses and revised dosing frequency in allergic asthma. The dosing level and frequency of omalizumab are guided by a dosing table based on the total serum IgE and bodyweight. Nonlinear mixed-effect pharmacokinetic (PK) and pharmacodynamic (PD) modeling and simulation techniques described the binding between omalizumab and its target IgE. The population PKPD analysis was conducted using data from the nine studies included originally in the European application of dosing table expansion together with three Japanese clinical studies to assess the influence of the ethnicity. Statistically significant differences between the ethnic groups were detected. These were small, within or close to bioequivalence criteria. The model described the primary pharmacology in Caucasian and Japanese patients, both adult and paediatric, with simulations showing that the interplay between the clearance, volume and binding affinity parameters was such that there was no clinical impact of the Japanese ethnic differences on either drug PK or free IgE suppression and hence the required posology.