Retrospective analysis of the efficacy of omalizumab in chronic refractory urticaria

Association Between Serum Total IgE Levels and Clinical Response to Omalizumab for Chronic Spontaneous Urticaria: A Systematic Review and Meta-Analysis

BACKGROUND

Omalizumab is the only biological agent approved for patients with chronic spontaneous urticaria (CSU), but no biomarker is well established for predicting clinical response to omalizumab.

OBJECTIVE

We aimed to determine the association between baseline total serum IgE levels and the effects of omalizumab in patients with CSU.

METHODS

PubMed, Web of Science, Scopus, and Cochrane Library were systematically searched for relevant studies from inception to August 23, 2022. The research protocol was registered on PROSPERO (CRD42022355592). No language restrictions were applied. A random-effects model was used for meta-analysis.

RESULTS

Ten interventional studies, including 1 randomized controlled trial, were included in the final meta-analysis, and a total of 866 patients with CSU were included. A pooled analysis showed significantly higher serum total IgE levels in complete responders (CRs) than in nonresponders (NRs) (mean difference [MD]: 56.509 IU/mL; 95% confidence interval [CI]: 24.230-88.789) and in partial responders (PRs) than in NRs (MD: 62.688 IU/mL; 95% CI: 32.949-92.427), but no significant difference was detected between CRs and PRs. The mean total IgE levels for CRs, PRs, and NRs were 163.154, 179.926, and 51.535 IU/mL, respectively. Further, the serum total IgE levels in early CRs were significantly higher compared with late CRs (MD: 55.194 IU/mL; 95% CI: 13.402-96.986). The sensitivity analyses with the leave-one-out method validated the robustness of all findings.

CONCLUSIONS

This systematic review and meta-analysis provide convincing evidence that pretreatment total serum IgE levels in patients with CSU are associated with clinical responses to omalizumab.

What Is the Role of Sex-Related Differences in the Effectiveness and Safety of Biological Drugs Used in Patients With Severe Asthma?

Biological drugs are used to treat severe asthma with an improvement of clinical symptoms. Data on sex difference of these drugs in patients with severe asthma are sparse. This study aimed to assess the effects of sex-related differences on biological drugs in patients with severe asthma. In this observational, open-label, prospective, noncontrolled, single-center cohort pilot study, we enrolled adult patients aged >18 years diagnosed with severe asthma and not previously treated with biological drugs. The first clinical end point was the statistical difference (P < .05) in the efficacy of biological drugs evaluated using the asthma control test and spirometry between sexes. The first safety end point was the statistical difference (P < .05) in developing adverse drug reactions between sexes. We enrolled 74 patients with severe asthma (48 women and 26 men) with a mean age of 59.4 (standard deviation, 11.8) years. The mean forced expiratory volume in 1 second was 6.9 (standard deviation, 13.9) for women and 9.4 (standard deviation, 10.7) for men and improved significantly after the treatment (P < .01), with no significant differences in sex (P = .8). Similarly, the asthma control test improved 12 months after the beginning of the treatment without significant differences between men and women (P = .5). The most common drug used was omalizumab (45.9% of the patients; P < .01) without significant differences between sex (P > .05). We did not observe the development of adverse drug reactions during the study. In conclusion, in asthmatic patients, sex does not have a role in either the effectiveness or safety of biological drugs.

Biologicals in Treatment of Chronic Urticaria: A Narrative Review

Chronic urticaria is a common inflammatory skin disease affecting around 0.5-1% of the world's population. The disease has a chronic indolent course which significantly affects the patient's quality of life. Urticaria pathogenesis involves cross-linking of immunoglobulin E (IgE) on mast cells causing degranulation which occurs by various pathways which leads to development of wheals and angioedema. The first-line treatment for chronic urticaria is non-sedating second-generation H1 antihistamines (AHs). After the advent of anti-IgE monoclonal antibody omalizumab, the response rate in resistant urticaria has improved significantly without any major adverse events. Other biologicals such as anti-IgE, anti-IL-5, anti-IL-1, anti-IL-17, and anti-CD20 monoclonal antibodies are under trial. These biologicals have better efficacy and safety profile as compared to conventional immunosuppressants. Even with the advances in the last decade, recurrence after stopping the therapy is common, and there is a need for better understanding of the pathogenesis and the drugs acting on the key pathways involved in urticaria. In this review, we provide the role of several biologicals in the treatment of chronic urticaria.

An Overview of Off-Label Use of Humanized Monoclonal Antibodies in Paediatrics

In recent years, off-label and unlicensed drug use has extensively developed in the paediatric population. For a long time, clinical trials in the paediatric population were considered complicated to perform because of ethical problems, causing frequent off-label use. Off-label drug use remains an important public health issue, especially for children with rare conditions or with diseases not responsive to conventional treatments. The present paper is a narrative review of the literature of off-label drug use in children. The aim of our study is to summarize the main works dealing with the off-label use of biological drugs in paediatrics. Further studies analyzing their efficacy, safety, and cost-benefit ratios are needed to extend the use of biological therapies to the paediatric population.

Sex and gender in asthma

Asthma is a heterogenous disease, and its prevalence and severity are different in males versus females through various ages. As children, boys have an increased prevalence of asthma. As adults, women have an increased prevalence and severity of asthma. Sex hormones, genetic and epigenetic variations, social and environmental factors, and responses to asthma therapeutics are important factors in the sex differences observed in asthma incidence, prevalence and severity. For women, fluctuations in sex hormone levels during puberty, the menstrual cycle and pregnancy are associated with asthma pathogenesis. Further, sex differences in gene expression and epigenetic modifications and responses to environmental factors, including SARS-CoV-2 infections, are associated with differences in asthma incidence, prevalence and symptoms. We review the role of sex hormones, genetics and epigenetics, and their interactions with the environment in the clinical manifestations and therapeutic response of asthma.

Predictors of treatment response in chronic spontaneous urticaria

The current therapeutic algorithm for chronic spontaneous urticaria (CSU), endorsed by the international guideline, entails treatment escalation from second-generation H₁ -antihistamines (sgAHs) to omalizumab and cyclosporine until complete response is achieved. Recently, several predictors of response to these treatment options have been described. Here, we discuss the most promising predictors of response and nonresponse to these treatments in CSU. A systematic search was performed by two independent researchers using the MEDLINE/PubMed database with specific keywords and 73 studies included in the review. Levels of evidence were categorized as strong (robust predictors), weak (emerging predictors) or no association, based on the outcome and number of studies available. High disease activity, high levels of C-reactive protein and D-dimer are robust predictors for a poor or no response to sgAHs. Poor or no response to omalizumab is robustly predicted by low serum levels of total IgE. A good response to cyclosporine is robustly predicted by a positive basophil histamine release assay, whereas low total IgE is an emerging predictor. The response to treatment with sgAHs, omalizumab and cyclosporine can be predicted by the use of markers that are readily available in routine clinical practice. Further studies are needed to confirm these predictors.

Safety and effectiveness of omalizumab for the treatment of chronic urticaria in pediatric patients

BACKGROUND

Evidence on safety and effectiveness of omalizumab for treatment of chronic urticaria in pediatric patients is scarce and limited to case reports. In particular, drug survival of omalizumab has not yet been investigated, which is a key element in the evaluation of its clinical performance. The aim of this study was to investigate safety, effectiveness, and drug survival rates of omalizumab in a daily practice cohort of pediatric patients with chronic urticaria (CU).

METHODS

This is a multicenter study including all pediatric patients from an academic center (Wilhelmina Children's Hospital) and a general center (Diakonessenhuis Hospital) in the Netherlands, who started omalizumab treatment before the age of 18 years. Data on safety, effectiveness, time to discontinuation, and reasons for discontinuation of treatment were assessed. Drug survival of omalizumab was estimated using the Kaplan-Meier survival analysis.

RESULTS

A total of 38 patients, who started treatment between January 2014 and January 2020, were included. Most patients (68.4%) used omalizumab without reporting any side effects and a complete or good response to treatment was achieved in 76.3% of patients. The 1- and 2-year drug survival rates were 62% and 50%, respectively, with well-controlled disease activity as the most frequent reason for discontinuation in 69.2% of patients, followed by ineffectiveness in 23.1% and side effects in 7.7% of patients.

CONCLUSIONS

This study demonstrates high safety and effectiveness of omalizumab treatment in pediatric patients with CU, which will aid clinical decision making and management of expectations when choosing omalizumab treatment for pediatric patients with CU.

Current and Potential Biologic Drugs for the Treatment of Chronic Urticaria

This article reviews biologic treatments that are currently applied for the treatment of severe chronic urticaria. Monoclonal anti-immunoglobulin E (omalizumab) is effective and safe in many patients, but accessibility and cost constitute barriers to its wider use. Questions on the optimal duration of the treatment and possible symptom recurrences after discontinuing the drug are still raised. A discussion is presented about several other biologics currently under investigation with potential to be incorporated in the near future in patients with severe chronic urticaria.

The KAAACI/KDA Evidence-Based Practice Guidelines for Chronic Spontaneous Urticaria in Korean Adults and Children: Part 2. Management of H1-Antihistamine-Refractory Chronic Urticaria

Quite a few patients with chronic spontaneous urticaria (CSU) are refractory to H₁-antihistamines, even though the dose of H₁-antihistamines is increased up to 4-fold. CSU that is not controlled with H₁-antihistamines results in increased disease burden. Several immunomodulators have been used to manage these patients. The guidelines reported herein are connected to Part 1 of the KAAACI/KDA Evidence-Based Practice Guidelines for Chronic Spontaneous Urticaria in Korean Adults and Children, and aimed to provide evidence-based recommendations for the management of H₁-antihistamine-refractory CSU. Part 2 focuses on the more commonly used additional treatment options for refractory CSU, including omalizumab, cyclosporine, leukotriene receptor antagonist, dapsone, methotrexate, and phototherapy. The evidence to support their efficacy, dosing, safety, and selection of these agents is systematically reviewed. To date, for patients with refractory CSU, the methodologically sound data to evaluate the use of omalizumab has been growing; however, the evidence of other immunomodulators and phototherapy is still insufficient. Therefore, an individualized stepwise approach with a goal of achieving complete symptom control and minimizing side effects can be recommended. Larger controlled studies are needed to elevate the level of evidence to select a rational therapeutic agent for patients with refractory CSU.

Benefits and Harms of Omalizumab Treatment in Adolescent and Adult Patients With Chronic Idiopathic (Spontaneous) Urticaria: A Meta-analysis of "Real-world" Evidence

Importance

Omalizumab is indicated for the management of chronic idiopathic urticaria (CIU) (also known as chronic spontaneous urticaria) in adolescents and adults with persistent hives not controlled with antihistamines. The effectiveness of omalizumab in the real-world management of CIU is largely unknown.

Objective

To quantitatively synthesize what is known about the benefits and harms of omalizumab in the real-world clinical management of CIU regarding urticaria activity, treatment response, and adverse events.

Data Sources

Published observational studies (January 1, 2006, to January 1, 2018) and scientific abstracts on the effectiveness of omalizumab in CIU were identified using PubMed, Embase, Web of Science, and Cochrane search engines; references were searched to identify additional studies.

Study Selection

Included studies were observational in design and included at least 1 outcome in common with other studies and at a concurrent time point of exposure to omalizumab. A total of 67 articles (35.2% of those screened) were included in the analysis.

Data Extraction and Synthesis

PRISMA and MOOSE guidelines were followed; independent selection and data extraction were completed by 2 observers. Random-effects meta-analyses were performed.

Main Outcomes and Measures

Main outcomes were change in weekly Urticaria Activity Score (UAS7; range, 0-42), change in Urticaria Activity Score (UAS; range 0-6) (higher score indicating worse outcome in both scales), complete and partial response rates (percentages), and adverse event rate (percentage).

Results

Omalizumab therapy was associated with an improvement in UAS7 scores (-25.6 points, 95% CI, -28.2 to -23.0; P < .001; 15 studies, 294 patients), an improvement in UAS scores (-4.7 points, 95% CI, -5.0 to -4.4, P < .001; 10 studies, 1158 patients), an average complete response rate of 72.2% (95% CI, 66.1%-78.3%; P < .001; 45 studies, 1158 patients) with an additional average partial response rate of 17.8% (95% CI, 11.7%-23.9%; P < .001; 37 studies, 908 patients), and an average adverse event rate of 4.0% (95% CI, 1.0%-7.0%; P < .001; any level of severity, 47 studies, 1314 patients).

Conclusions and Relevance

Benefits and safety of omalizumab in the real-world treatment of CIU meet or exceed results gleaned from clinical trials. These real-world data on omalizumab in CIU may help inform both clinical treatment expectations and policy decision making.

Cutting Edge: Biomarkers for Chronic Spontaneous Urticaria

Chronic spontaneous urticaria (CSU) is defined by the appearance of wheals and a variable presence of angioedema which persists for at least 6 weeks. It represents the most common subtype of chronic urticaria and is gaining importance in civil society because of its association with impaired quality of life. Moreover, CSU has a growing impact on national health systems representing a great burden due to its variable rate of response to the approved therapies. In this scenario, the identification of clinical and molecular biomarkers is of pivotal importance. Some groups are trying to detect molecules which would be able to help clinicians in reaching a proper diagnosis; additionally, the opportunity to describe disease severity which leads to cluster patients in different groups could fill the gap in the numerous unmet clinical needs. Several biomarkers are currently being studied with the purpose to predict the response to a defined therapy; unfortunately, none of them are ready to be translated from bench to bedside.

Effectiveness of omalizumab in adolescent and adult patients with chronic idiopathic/spontaneous urticaria: a systematic review of 'real-world' evidence

INTRODUCTION

Chronic idiopathic/spontaneous urticaria (CIU/CSU) is a dermatological condition characterized by itchy wheals and/or angioedema of continuous or intermittent duration of ≥6 weeks with a high burden of disease and impact on quality of life. Omalizumab is a recombinant humanized monoclonal antibody that inhibits the binding of IgE to high affinity receptors, and is approved for the CIU/CSU indication. The objective of this systematic review was to evaluate and synthesize the evidence on the real-world effectiveness of omalizumab in CIU/CSU in daily clinical practice.

AREAS COVERED

This review of 84 observational effectiveness studies covers treatments (dosing, medication use), clinical outcomes (treatment response, disease activity, quality of life), and safety.

EXPERT OPINION

The clinical outcomes observed across studies underscore the real-world effectiveness of omalizumab in the management of CIU/CSU. Continued treatment may assist patients showing an initial response to achieve a complete treatment response. Response rates are aligned with observed changes in disease activity, symptom experience, and quality of life, and this across subtypes of CIU/CSU. The positive therapeutic profile is complemented by a positive safety profile. The real-world evidence summarized here points convincingly at the high degree of effectiveness of omalizumab in the treatment of CIU/CSU in daily clinical practice.

Management of Pediatric Urticaria with Review of the Literature on Chronic Spontaneous Urticaria in Children

There are substantial knowledge gaps related to diagnosis and management of pediatric cases of chronic urticaria, and in particular chronic spontaneous urticaria (CSU). In this article we aimed to review the diagnosis and management of chronic urticaria in children and CSU in particular. We conducted a systematic review of articles published in English and French on pediatric CSU management in the last 10 years. We included experimental studies (eg, randomized controlled trials), other experimental designs (eg, nonrandomized methods of assignment, controlled before-after studies, and interrupted time series), and observational studies (eg, prospective or retrospective cohort studies, cross-sectional studies, case-control studies, and case reports). Our findings highlight the efficacy of second-generation antihistamines for the treatment of CSU in children and supports the use of omalizumab for more severe cases. However, our study also reveals severe knowledge gaps related to the best management strategy in children with more severe/refractory cases of CSU. Future studies are required to establish the beneficial effect of high doses of second-generation antihistamines as well as the effectiveness and safety of omalizumab and other biologics in young children.

Real-world treatment patterns and outcomes of omalizumab use in patients with chronic idiopathic urticaria

OBJECTIVE

To examine treatment patterns, treatment response, and demographic and clinical characteristics of patients with chronic idiopathic urticaria (CIU) newly initiated on omalizumab therapy in real-world practice in the US.

METHODS

This retrospective observational cohort study used US claims data from the HealthCore Integrated Research Database (HIRD^®) augmented with medical record data to identify CIU patients newly-treated with omalizumab (≥4 omalizumab claims within 6 months of initial claim; index date = first omalizumab claim date) between March 21, 2014 and October 31, 2015 and with ≥6 months pre- and ≥12 months post-index health plan eligibility. Study outcomes were captured from medical records for up to 12 months pre-index and up to 24 months post-index. Descriptive statistics were reported.

RESULTS

This study consisted of 88 patients with a mean (SD) age of 43.4 (± 13.46) years, 68.2% were female, and 36 patients had ≥18 months post-index eligibility. Among 69 patients with documented index dose, 75.4% received omalizumab 300 mg and 69.6% remained on index dose throughout follow-up. For 52 patients with documented index dosing frequency, 96.2% had every 4-week dosing frequency. Among 86 patients with omalizumab documentation, 83.7% reported CIU improvement after omalizumab initiation and 24.4% discontinued omalizumab. For all patients, the proportion using oral corticosteroids (OCS) decreased pre- to post-index (52.3% vs 39.8%). Similar results were observed for patients with ≥18 months post-index eligibility.

CONCLUSIONS

In this real-world analysis, the majority of patients remained on omalizumab for ≥12 months, and had a positive response. OCS use decreased following omalizumab initiation.

Gender aspects and influence of hormones on bronchial asthma - Secondary publication and update

There is good evidence for gender-specific differences in asthma regarding all affected areas, from intra- to extra-cellular mediators to the whole organ structure und functioning of the lung. These result from complex, in parts synergistic, in other parts opposing, effects - especially of female sex hormones, and rather protective effects of male hormones against asthma, which include effects on the cellular immune system. Additionally, there are gender differences of sociocultural origin, regarding presentation, doctor's diagnosis and treatment of asthma symptoms, as well as the undertaken coping strategies concerning the female or male patient's complaints. Taking into account gender-specific differences in asthma would contribute to improved individual diagnosis and therapies.

Omalizumab efficacy in cases of chronic spontaneous urticaria is not explained by the inhibition of sera activity in effector cells

Omalizumab (OmAb) is a humanized anti-IgE antibody approved for the treatment of chronic spontaneous urticaria (CSU). OmAb's mechanism of action is known to include actions on free IgE and on pre-bound IgE. However, OmAb is equally and rapidly effective against autoimmune and non-autoimmune urticaria where IgE involvement is not clear, suggesting the involvement of additional mechanisms of action. In this study, we sought to investigate the ability of OmAb to inhibit mast cell and basophil degranulation induced by sera from CSU patients. For this purpose, we performed a comparison between the in vitro incubation of sera from CSU patients treated with OmAb and the in vivo administration of OmAb in a clinical trial. We found that OmAb added in vitro to sera from CSU patients did not modify the ability of the sera to induce cell degranulation. Similarly, the sera from patients treated with OmAb in the context of the clinical trial who had a good clinical outcome maintained the capacity to activate mast cells and basophils. Thus, we conclude that the beneficial activity of OmAb does not correlate with the ability of patient sera to induce cell degranulation.

Biologic Therapy in the Treatment of Chronic Skin Disorders

Understanding of the immunologic pathways involved in the pathogenesis of skin-related diseases is constantly advancing. Several biologic agents play important therapeutic roles for management of patients with chronic urticaria, atopic dermatitis, and psoriasis, particularly omalizumab for antihistamine-resistant chronic urticaria, interleukin (IL)-1 inhibitors for cryopyrin-associated periodic syndrome and Schnitzler syndrome, dupilumab for recalcitrant atopic dermatitis, and IL-17 inhibitors for psoriasis. The therapeutic utility of biologic agents for patients with immune-related dermatologic disorders is likely to expand in the future. This article reviews the data regarding biologic agents and their utility in the management of specific skin-related disorders.

Treatment of Chronic Spontaneous Urticaria with a Single Dose of Omalizumab: A Study of Four Cases

Background:

Chronic spontaneous urticaria (CSU) has a detrimental effect on patients’ emotional and physical quality of life. Omalizumab, an anti-immunoglobulin E humanized monoclonal antibody, has been shown to be very effective in the treatment of refractory chronic urticaria patients but may not be an economically viable option for all CSU patients. However, we present a case series where a single dose of omalizumab gave sustained relief of symptoms in patients with CSU, which may be an economical option.

Aims:

The aim of this study is to assess the efficacy of a single dose of omalizumab in the treatment of CSU. Materials and Methods: Four patients of CSU whose disease was not controlled with four times the licensed dose of tablet fexofenadine 180 mg were exhibited one subcutaneous injection of omalizumab and were followed up at 4 weekly intervals for 24 weeks for Weekly Urticaria Activity Score 7 (UAS7) and Dermatology Life Quality Index (DLQI).

Results:

A sharp decline in UAS7 and DLQI was documented in 7–10 days. The decline was maintained up to 16 weeks in one case and 20 weeks in the other three cases. Both the scores at the end of the follow-up period of 24 weeks were better than the pre-omalizumab scores.

Conclusion:

The results of this case series indicate the efficacy of a single-dose omalizumab in treating moderate to severe refractory CSU. Further studies are required to identify the minimum frequency of administering omalizumab to effectively control CSU. This would greatly reduce the cost of this novel therapy.

Omalizumab in Chronic Spontaneous Urticaria: A Brazilian Real-Life Experience

BACKGROUND

Current guidelines on chronic spontaneous urticaria (CSU) suggest a treatment based on a 3-step approach that aims at total symptom control, starting with H1-antihistamines. However, a significant number of patients present an antihistamine-resistant urticaria that must be treated with an alternative third-line therapy such as omalizumab.

METHODS

Patients with a history of CSU who did not respond to treatment with high doses of modern antihistamines were treated with 150 or 300 mg of omalizumab every 4 weeks. The response to treatment was recorded as complete (CR), partial (PR) or no response. A dose adjustment was proposed according to response.

RESULTS

We treated 47 CSU patients with omalizumab (40 females), of whom 39.5% had evidence of autoimmunity. The average number of treatments was 11.4 (range 2-87). All patients had been refractory to high-dose modern antihistamines. A CR was seen in 84.6% of patients who started with 300 mg and in 60% of those who started with 150 mg. Only 1 patient had no response to both the 150- and 300-mg doses. In 6 of the PR patients with 150 mg, a higher dose of 300 mg was proposed and 4 had a CR. Four patients discontinued the treatment. No severe adverse events were reported in the patients who finished the study.

DISCUSSION

Although good results were seen in both groups, CR rates were higher in those under a high-dose initial treatment. Our data strongly suggest that the therapy should be individualized.

Omalizumab for the treatment of chronic spontaneous urticaria: A meta-analysis of randomized clinical trials

BACKGROUND

Chronic spontaneous urticaria (CSU) is defined by itchy hives, angioedema, or both for at least 6 weeks. Omalizumab, an anti-IgE antibody that affects mast cell and basophil function, is a promising new treatment option. As of now, however, the efficacy and safety of different doses of omalizumab used in clinical trials for CSU have not been systematically analyzed and summarized.

OBJECTIVE

We sought to assess the efficacy and safety of different doses of omalizumab for the treatment of CSU in a meta-analysis of clinical trial results.

METHODS

Suitable trials were identified by searching PubMed, Medline, Embase, and Web of Science databases and with the help of omalizumab's manufacturers. Only double-blind, randomized, placebo-controlled studies with omalizumab-treated versus placebo-treated patients with CSU were included in this analysis.

RESULTS

We identified 7 randomized, placebo-controlled studies with 1312 patients with CSU. Patients treated with omalizumab (75-600 mg every 4 weeks) had significantly reduced weekly itch and weekly wheal scores compared with the placebo group. Omalizumab's effects were dose dependent, with the strongest reduction in weekly itch and weekly wheal scores observed with 300 mg. Rates of complete response were significantly higher in the omalizumab group (relative risk, 4.55; P < .00001) and dose dependent, with the highest rates in the 300-mg group. Rates of patients with adverse events were similar in the omalizumab and placebo groups.

CONCLUSION

This meta-analysis provides high-quality evidence for the efficacy and safety of omalizumab in patients with CSU and for treating these patients with 300 mg of omalizumab every 4 weeks.

Omalizumab-A Review

Omalizumab is a recombinant, humanized, monoclonal antibody against human immunoglobulin E (IgE). The US FDA has approved this molecule for chronic urticaria.

The use of biologicals in cutaneous allergies - present and future

PURPOSE OF REVIEW

Up-to-date biologicals in cutaneous allergies play - unfortunately - only a minor role. However, this situation might change. Recently, omalizumab was licensed for chronic urticaria; this article reviews recent advances in the use of biologicals in cutaneous allergies.

RECENT FINDINGS

Interestingly, the mechanism of omalizumab appears to be different in urticaria and allergic asthma for which the drug has been licensed previously. In urticaria dosage is not dependent on serum IgE-levels and response is seen very often after only 12 h. Other indications in cutaneous allergy in which biologicals have been investigated, at least in case reports or small studies, are TNF-α-antagonists and rituximab in chronic urticaria, omalizumab, rituximab and TNF-α-antagonists in atopic dermatitis as well as mepolizumab in this disease. However, all these studies appear to show a benefit for individual patients but not a clear breakthrough for the whole group of patients involved. This, however, might also be one of the future approaches that sub-groups of patients who have different responses to biologicals may be identified, as apparently different cytokine patterns are predominantly involved in the individual patient.

SUMMARY

In conclusion, although currently only one biological is approved in chronic urticaria, there is hope that a rapid better understanding of individual disease factors will support the development of other novel drugs in this field.

Biologic agents and the therapy of chronic spontaneous urticaria

PURPOSE OF REVIEW

Chronic spontaneous urticaria (CSU) has been traditionally managed with antihistamines. Over the years, studies using different formulations and dosing regimens have delineated the limits of their effectiveness, thus emphasizing the need for alternative therapeutic approaches. Data keep accumulating that the monoclonal anti-immunoglobulin E antibody omalizumab, until recently reserved for the treatment of severe atopic asthma, may have a beneficial therapeutic and safety profile for CSU cases resistant to the effect of antihistamines.

RECENT FINDINGS

Since the beginning of 2013, a host of studies have been published paving the way for licensing of omalizumab for the treatment of CSU. Dose-finding studies have indicated 300 mg monthly as a possible optimal treatment regimen. Efficacy proving randomized controlled trials were further supported by open-label studies confirming its effectiveness in real life. One report has been published so far presenting positive data about the use of another biologic agent, rituximab, depleting the blood stream of B cells, in patients with CSU.

SUMMARY

New convincing evidence in support of the efficacy and safety of omalizumab in the treatment of CSU has accumulated over the past year, providing another tool for coping with the antihistamine-resistant cases.

The potential pharmacologic mechanisms of omalizumab in patients with chronic spontaneous urticaria

In patients given a diagnosis of chronic spontaneous urticaria (CSU), there are no obvious external triggers, and the factors that initiate the clinical symptoms of wheal, flare, and itch arise from within the patient. Most patients with CSU have an autoimmune cause: some patients produce IgE autoantibodies against autoantigens, such as thyroperoxidase or double-stranded DNA, whereas other patients make IgG autoantibodies against FcεRI, IgE, or both, which might chronically activate mast cells and basophils. In the remainder of patients with CSU, the nature of the abnormalities has not yet been identified. Accumulating evidence has shown that IgE, by binding to FcεRI on mast cells without FcεRI cross-linking, can promote the proliferation and survival of mast cells and thus maintain and expand the pool of mast cells. IgE and FcεRI engagement can also decrease the release threshold of mast cells and increase their sensitivity to various stimuli through either FcεRI or other receptors for the degranulation process. Furthermore, IgE-FcεRI engagement potentiates the ability of mast cells to store and synthesize de novo inflammatory mediators and cytokines. Administration of omalizumab, by virtue of its ability to deplete IgE, attenuates the multiple effects of IgE to maintain and enhance mast cell activities and hence reduces the ability of mast cells to manifest inflammatory mechanisms in patients with CSU.