Omalizumab in children and adolescents with chronic urticaria: A 16-week real-world study

Managing Chronic Urticaria in Children: An Update

PURPOSE OF REVIEW

To provide an update and new insights into the management of pediatric patients with chronic urticaria.

RECENT FINDINGS

Chronic urticaria in children may be more prevalent than previously thought, with a high resolution rate within two years. Patient-reported outcome measures (PROMs) are effective tools for assessing disease severity and control in pediatric populations. Children with chronic urticaria generally respond better to H1-antihistamines compared to adults. For patients refractory to antihistamines, omalizumab has shown excellent efficacy. Additionally, dupilumab has emerged as a potential treatment option, as it has been approved for chronic spontaneous urticaria in some countries. Managing chronic urticaria in children remains a diagnostic and therapeutic challenge. However, advancements in understanding disease mechanisms, the validation of tools to assess disease activity and control, the development of reliable biomarkers, and the availability of novel therapies offer significant promise. These developments will enable more effective treatment and improved outcomes for pediatric patients.

Chronic urticaria treatment challenges in children

OBJECTIVE

This paper aims to review the efficacy and safety of current chronic urticaria (CU) treatment in children and the existing patient-reported outcome measures (PROMs) used in this age group.

DATA SOURCE

Since there are few studies of CU in children, the authors performed a non-systematic review of published articles in English, Spanish, and Portuguese in the PubMed database in the last decade. Keywords used were (antihistamines OR omalizumab OR cyclosporine OR treatment) AND (chronic urticaria) AND (children OR adolescents).

DATA SYNTHESIS

According to the current guideline's algorithm, the treatment of CU involves using high doses of antihistamines when there is no response with the licensed dosage. The effectiveness of this increase in children has been demonstrated with control rates ranging from 35% to 92%, with few studies addressing safety profiles. Omalizumab is approved for children over 12 years of age as a second step in the algorithm. Although more studies with children are needed to assess its effectiveness and safety, some data show complete control of symptoms in more than 80% of pediatric cases with no adverse effects, including in children under 12 years. When monitored closely, cyclosporine showed a good response rate in pediatric CU with few adverse events. Also, PROMs validated for this age can be helpful in clinical decisions, such as Urticaria Activity Score summed over 7 days, Urticaria Control Test, and Chronic Urticaria Quality of Life Questionnaire.

CONCLUSIONS

Collaborative studies are necessary to generate stronger evidence to support the guideline recommendations for children. The existing data indicate that these drugs are safe and effective for treatment when dose adjustments are made.

Biological drugs for the treatment of children with chronic spontaneous urticaria

INTRODUCTION

There is a significant prevalence of chronic spontaneous urticaria (CSU) in children across the globe. Some children with CSU do not achieve disease control with first-line antihistamine treatment and may need anti-IgE therapy with omalizumab. Recently, several novel treatment options, including dupilumab and BTK inhibitors, showed promising results in the treatment of antihistamine-refractory CSU in adults. However, information regarding their use in pediatric CSU is scarce, and most data is extrapolated from adult studies.

AREAS COVERED

The review highlights the evidence on the use of mAbs and small-molecule inhibitors in pediatric CSU and aims to bridge the knowledge gaps and highlight unmet needs.

EXPERT OPINION

Omalizumab is approved for allergic asthma patients aged ≥6 years, and some experience with omalizumab in children with CSU at this age has been published. However, approximately 5-10% of pediatric CSU patients may show insufficient response to omalizumab, necessitating other therapies. The available information on the off-label use of biologics other than omalizumab in children is limited to case reports. No data is available for other new therapies.

Therapies for Chronic Spontaneous Urticaria: Present and Future Developments

Chronic spontaneous urticaria (CSU) is a complex dermatological condition characterized by recurrent wheals and/or angioedema lasting for more than six weeks, significantly impairing patients' quality of life. According to European guidelines, the first step in treatment involves second-generation H1-antihistamines (sgAHs), which block peripheral H1 receptors to alleviate symptoms. In cases with inadequate responses, the dose of antihistamines can be increased by up to fourfold. If symptoms persist despite this adjustment, the next step involves the use of omalizumab, a monoclonal anti-IgE antibody, which has shown efficacy in the majority of cases. However, a subset of patients remains refractory, necessitating alternative treatments such as immunosuppressive agents like cyclosporine or azathioprine. To address these unmet needs, several new therapeutic targets are being explored. Among them, significant attention is being given to drugs that block Bruton's tyrosine kinase (BTK), such as remibrutinib, which reduces mast cell activation. Therapies like dupilumab, which target the interleukin-4 (IL-4) and IL-13 pathways, are also under investigation. Additionally, molecules targeting the Mas-related G protein-coupled receptor X2 (MRGPRX2), and those inhibiting the tyrosine kinase receptor Kit, such as barzolvolimab, show promise in clinical studies. These emerging treatments offer new options for patients with difficult-to-treat CSU and have the potential to modify the natural course of the disease by targeting key immune pathways, helping to achieve longer-term remission. Further research is essential to better elucidate the pathophysiology of CSU and optimize treatment protocols to achieve long-term benefits in managing this condition. Altogether, the future of CSU treatments that target pathogenetic mechanisms seems promising.

Clinical Characteristics, Investigations and Treatment in Children with Chronic Urticaria: An Observational Study

Background and Objectives: The guidelines for chronic urticaria in children contain recommendations that are often based on adult studies. The diagnostic pathway has not been standardized and the effectiveness of anti-H1, omalizumab, montelukast, and systemic glucocorticoids is rarely reported in the pediatric population. There is a wide variation in the rate of remission of chronic urticaria between studies. The aim of this study is to enhance our understanding of pediatric chronic urticaria. Materials and Methods: This study enrolled 37 children with chronic urticaria aged from 0 to 18 years. Demographic parameters, medical history, clinical features, laboratory data and treatment information were collected. Children were treated with the recommended dosage of second-generation H1-antihistamines, which was increased by up to twofold. Omalizumab was added for refractory anti-H1 patients. A three-day course with systemic glucocorticoids was administered for severe exacerbations. Montelukast was administered to some children. Results: Wheals without angioedema were common. Chronic urticaria was spontaneous in 32 children (86.48%), inducible in 2 (5.41%), induced by a parasite in 1 and vasculitic in 2. Treatment of the potential causes of chronic urticaria was of no benefit, except for eradication of Dientamoeba fragilis. Chronic urticaria was resolved within three years in 45.9% of cases. Allergic diseases were present in nine children (24.32%) and autoimmune diseases were present in three (8.11%). All children were treated with anti-H1 at the licensed dose or at a higher dose. A partial or complete response to anti-H1 was observed in 29 (78.38%) patients. Montelukast showed no benefit. All children treated with omalizumab responded. Systemic glucocorticoids were successfully used to treat exacerbations. Conclusions: Our findings indicate that laboratory tests should not be routinely performed in children with chronic urticaria without clinical suspicion. However, comorbidities such as thyroid autoimmune disease and coeliac disease are suggested to be monitored over the chronic urticaria course. These clinical conditions could be diagnosed from the diagnostic framework of chronic urticaria. Increasing the dosage of anti-H1 and omalizumab was effective in children resistant to standard treatment but we still need further studies to generate a standard patient-centered treatment.

Current state and advances in desensitization for peanut allergy in pediatric age

Peanut allergy affects about 1%-3% of the pediatric population in the world, with an important increase in the last decades. Nowadays, international guidelines recommend the early introduction of peanuts in the infant diet, with poor information about the quantity and the frequency of the intake. Allergen immunotherapy may represent the only therapeutic strategy able to modify the natural history of peanut allergy. In particular, oral immunotherapy showed the most promising results in terms of efficacy, but with significant rates of adverse reactions, mostly gastrointestinal. In 2020, the Food and Drug Administration and the European Medicines Agency approved Palforzia®, an oral drug for patients aged 4-17 years. Several studies are ongoing to improve the tolerability of oral immunotherapy and standardize the desensitization protocols. Sublingual immunotherapy permits to offer much lower doses than oral immunotherapy, but fewer adverse events are shown. Subcutaneous immunotherapy is associated with the greatest systemic adverse effects. Epicutaneous immunotherapy, for which Viaskin® patch was approved, has the highest safety profile. Innovative studies are evaluating the use of biological drugs, such as omalizumab or dupilumab, and probiotics, such as Lactobacillus rhamnosus, in monotherapy or associated with oral immunotherapy. Therapy for peanut allergy is constantly evolving, and new perspectives are ongoing to develop.

Omalizumab for Patients with Chronic Spontaneous Urticaria: A Narrative Review of Current Status

Chronic spontaneous urticaria (CSU) is a debilitating inflammatory disorder of the skin, characterized by a fluctuating natural history, a complex mechanism of action, and a significant burden on patients, including effect on quality of life, development of psychosocial disorders, and a range of comorbidities. Recent international guidelines recommend a therapeutic approach of first-line treatment with second generation H1-antihistamines and second-line treatment with the biologic omalizumab. Here, the salient aspects of CSU and current status of data for omalizumab for patients with CSU are reviewed, with a focus on mechanism of action, efficacy and real-world effectiveness (including patient outcomes, response, relapse, and remission), and safety (including consideration of the risk of anaphylaxis). The review also considers recent data on COVID-19, CSU, and omalizumab and presents our perspective on future needs. Overall, the data suggest that omalizumab is an effective and well-tolerated treatment for patients with CSU that provides benefits for a wide range of patients.

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.

Pediatric usage of Omalizumab: A promising one

Allergic and related diseases have a substantial epidemiological impact on the pediatric population. Small molecule-based medicines have been traditionally used to manage the diseases. Omalizumab is the first monoclonal antibody-based medicine used in children's allergy and shows great promises. It binds to free IgE and prevents it from binding to IgE receptors, thus interrupting the IgE-dependent allergic inflammatory cascade. Vast amounts of data demonstrate its effectiveness and well tolerance by patients, including the children. However, the drug was only approved to use in allergic asthma and chronic spontaneous urticaria (CSU), though other applications were explored in clinical trials. In this review, we summarized current pediatric applications of omalizumab in allergic diseases, focusing on its usages beyond asthma and CSU, including allergic rhinitis, allergic bronchopulmonary aspergillosis, vernal keratoconjunctivitis, food allergy and atopic dermatitis. In addition, we highlighted the unmet needs and controversial issues of anti-IgE therapy.

Expert consensus on the use of omalizumab in chronic urticaria in China

Chronic urticaria (CU) is a debilitating skin disease that lasts for more than 6 weeks with wheals and/or angioedema, including chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU). In China, the prevalence of this disease is high, more than 1%, and on the rise. CU has a major impact on the quality of life (QoL) of patients who frequently experience sleep disturbance, depression, and anxiety. Nearly one-third of patients with CSU, in China, are resistant to second-generation H1-antihistamines (sgAHs), even at a fourfold dose (second line; off-label). Omalizumab is approved for the treatment of CSU treatment in Europe and shows remarkable efficacy and safety. In China, regulatory approval for the use of omalizumab is pending, and its use in clinical practice varies widely. Consensus on omalizumab CU treatment in China is urgently needed. The aim of this article is to propose a practical omalizumab treatment algorithm for the management of antihistamine-resistant CSU and CIndU in adults and special population including children and adolescents, and pregnant or breast feeding women, to guide daily clinical practice in China. In the development of this consensus, an expert group including mainly dermatologists, allergists, but also pulmonologists, ENTs, immunologists, and pediatricians in Allergic Disease Prevention and Control Committee, Chinese Preventive Medicine Association, reviewed the existing evidence and developed consensus on the use of omalizumab in CU patients from China. The goal of this consensus is to assist clinicians in making rational decisions in the management of refractory CU with omalizumab. The key clinical questions covered by the treatment algorithm are: 1) Omalizumab treatment routine strategy in both CSU and CIndU patients; 2) Recommended dose and treatment duration for different age stratification; 3) Treatment duration for CU patients with other allergic comorbidities; 4) Recommendation on omalizumab stopping strategy.

Chronic Urticaria: Advances in Understanding of the Disease and Clinical Management

Chronic urticaria (CU) is a common skin condition characterized by the recurrence of wheals, with or without angioedema, which lasts for at least 6 weeks. Owing to its pruritus and incurability, this disease adversely affects the patients' physical and mental health and diminishes the quality of life. CU is generally classified into two subtypes based on the relevance of eliciting factors: chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU), the latter of which is further divided into several subtypes. To improve the understanding and clinical management of this highly heterogeneous disorder, the EAACI/GA²LEN/EDF/WAO guideline was developed and published in 2018 based on evidence and expert consensus. The diagnostic and treatment algorithms proposed by the guideline have largely facilitated dermatologists in clinical practice. However, several questions remained unsolved and have been widely investigated in the recent years. First, a better understanding of the association between chronic urticaria and its potential underlying causes or eliciting factors such as autoimmunity, infections, coagulation aberrance, and vitamin D deficiency is warranted. This would lead to updates in the diagnostic and treatment procedures of different subtypes of chronic urticaria. Secondly, treatment for recalcitrant cases, especially those resistant to or intolerant of second-generation antihistamines and (or) omalizumab, calls for novel therapeutic measures or strategies. In the present review, we summarized recent advances in the understanding and management of both CSU and CIndU, with special emphasis on their underlying causes or eliciting factors, pathogenic mechanisms, potential targets for intervention, and advances in treatment strategies.

The Emerging Role of Mast Cells in Response to Fungal Infection

Mast cells (MCs) have been considered as the core effector cells of allergic diseases. However, there are evidence suggesting that MCs are involved in the mechanisms of fungal infection. MCs are mostly located in the border between host and environment and thus may have easy contact with the external environmental pathogens. These cells express receptors which can recognize pathogen-associated molecular patterns such as Toll-like receptors (TLR2/4) and C-type Lectins receptors (Dectin-1/2). Currently, more and more data indicate that MCs can be interacted with some fungi (Candida albicans, Aspergillus fumigatus and Sporothrix schenckii). It is demonstrated that MCs can enhance immunity through triggered degranulation, secretion of cytokines and chemokines, neutrophil recruitment, or provision of extracellular DNA traps in response to the stimulation by fungi. In contrast, the involvement of MCs in some immune responses may lead to more severe symptoms, such as intestinal barrier function loss, development of allergic bronchial pulmonary aspergillosis and increased area of inflammatory in S. schenckii infection. This suggests that MCs and their relevant signaling pathways are potential treatment regimens to prevent the clinically unwanted consequences. However, it is not yet possible to make definitive statements about the role of MCs during fungal infection and/or pathomechanisms of fungal diseases. In our article, we aim to review the function of MCs in fungal infections from molecular mechanism to signaling pathways, and illustrate the role of MCs in some common host-fungi interactions.