Long-term management of chronic spontaneous urticaria with omalizumab

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.

Biomarkers for Monitoring Treatment Response of Omalizumab in Patients with Chronic Urticaria

Chronic urticaria (CU) is a debilitating skin disease affecting around 1% of the population. CU can be subdivided into chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU). Different pathophysiological mechanisms have been proposed to play a role in the development of CU, and these are also being investigated as potential biomarkers in the diagnosis and management of the disease. As of now the only assessment tools available for treatment response are patient reported outcomes (PROs). Although these tools are both validated and widely used, they leave a desire for more objective measurements. A biomarker is a broad subcategory of observations that can be used as an accurate, reproducible, and objective indicator of clinically relevant outcomes. This could be normal biological or pathogenic processes, or a response to an intervention or exposure, e.g., treatment response. Herein we provide an overview of biomarkers for CU, with a focus on prognostic biomarkers for treatment response to omalizumab, thereby potentially aiding physicians in personalizing treatments.

Stepping Down Treatment in Chronic Spontaneous Urticaria: What We Know and What We Don't Know

In chronic spontaneous urticaria (CSU), wheals, angioedema, or both appear spontaneously for > 6 weeks. Current recommended treatment options for urticaria target mast cell mediators such as histamine, or activators, such as autoantibodies. The goal of CSU treatment is to treat the disease until it is gone as effectively and safely as possible. As no cure is available for CSU as of now, the treatment is aimed at continuously suppressing disease activity, with complete control of the disease and a normalization of quality of life. To achieve this, pharmacological treatment should be continued until no longer needed. Treatment of CSU should follow the basic principles of treating as much as needed and as little as possible taking into consideration that the activity of the disease may vary. Since CSU is a disease with spontaneous remission, it is hard to tell, in patients with complete control and no signs or symptoms, when medication is no longer needed. The current international guideline for urticaria suggests that the treatment can be stepped down once a patient is free of signs and symptoms. Other reasons for stepping down the treatment of CSU patients include safety concerns or issues, pregnancy or wanting to become pregnant, and economic factors. As of now, it is unclear over which period, with what intervals and with which dosages CSU treatment should be stepped down. Guidance on this is needed for all recommended therapies: (i) standard-dosed second-generation H1-antihistamine (sgAH), (ii) higher than standard-dosed sgAH, (iii) standard-dosed omalizumab, (iv) higher than standard-dosed omalizumab, and (v) cyclosporine. However, there is a lack of controlled trials on the step down and discontinuation of these treatments. Here, we aim to provide a summary of what is known and what needs to be investigated in further studies, based on our own experience and real-world evidence.

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.

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.

A patient-oriented approach to long-term use of omalizumab in chronic spontaneous urticaria

BACKGROUND

Omalizumab is an effective and safe treatment for antihistamine resistant chronic spontaneous urticaria (CSU), however, long-term efficacy and safety remains unclear.

OBJECTIVE

To evaluate the efficacy and safety of omalizumab in CSU patients treated for long term and to identify long-term management strategies.

METHODS

We retrospectively analyzed demographic characteristics, clinical features, laboratory parameters and treatment outcomes of 41 CSU patients who received omalizumab for at least 3 years. Treatment responses were evaluated with urticaria control test (UCT). Treatment safety was evaluated by comparing laboratory findings before and three years after omalizumab initiation as well as considering patients' adverse event reports.

RESULTS

The patients (mean age 40.46 years; 63.4% women) received omalizumab for an average of 41.93 months (mean 31.68 injections/patient). The mean baseline UCT score was 5.56 and average number of injections to reach UCT score ≥12 was 3.3. Nine patients (22%) responded insufficiently to 300 mg/4 weeks omalizumab and required updosing. Thirty-eight patients (92.7%) could tolerate longer dose intervals (>4 weeks) and the dose interval was increased after a mean of 11.53 injections. There was no loss of efficacy of omalizumab. Sixteen patients (39%) had been retreated with omalizumab after a mean discontinuation time of 24 weeks. Five patients (12.2%) reported mild and transient adverse effects. Liver and renal function tests as well as full blood count before and after omalizumab were in normal ranges.

CONCLUSION

For the long-term management of CSU, omalizumab is a safe and effective treatment which can be tailored according to patients' disease activity.

Managing Chronic Urticaria and Recurrent Angioedema Differently with Advancing Age

Angioedema and urticaria affect people of all ages. Accurate diagnosis and optimum management is essential for healthy aging. Older people continue to experience mast cell-mediated urticaria and angioedema, with a higher prevalence of autoimmune and a lower prevalence of autoallergic disease. Bradykinin-mediated angioedemas are more common in the elderly because of their association with angiotensin-converting enzyme inhibitor (ACEI) treatment. Acquired C1-inhibitor deficiency, another bradykinin-mediated angioedema, occurs predominantly in older people, whereas hereditary angioedema due to C1-inhibitor deficiency continues to cause symptoms, even in old age. Drug-induced angioedemas disproportionately affect older people, the most frequent users of ACEIs, aspirin, and nonsteroidal anti-inflammatory drugs. Accurate diagnosis and targeted treatment prevent unnecessary morbidity and mortality. Second-generation antihistamines with omalizumab if required are effective and well tolerated in older people with mast cell-mediated urticaria. For bradykinin-mediated angioedemas, these drugs are ineffective. C1-inhibitor replacement or blockade of kallikrein or the bradykinin B2 receptor of the contact pathway is required to treat hereditary angioedema and may be considered in other bradykinin-mediated angioedemas, if supportive treatment is insufficient. For aspirin-related angioedema and urticaria, alternative medications or, exceptionally, desensitization may be required.

Visible light. Part I: Properties and cutaneous effects of visible light

Approximately 50% of the sunlight reaching the Earth's surface is visible light (400-700 nm). Other sources of visible light include lasers, light-emitting diodes, and flash lamps. Photons from visible light are absorbed by photoreceptive chromophores (e.g., melanin, heme, and opsins), altering skin function by activating and imparting energy to chromophores. Additionally, visible light can penetrate the full thickness of the skin and induce pigmentation and erythema. Clinically, lasers and light devices are used to treat skin conditions by utilizing specific wavelengths and treatment parameters. Red and blue light from light-emitting diodes and intense pulsed light have been studied as antimicrobial and anti-inflammatory treatments for acne. Pulsed dye lasers are used to treat vascular lesions in adults and infants. Further research is necessary to determine the functional significance of visible light on skin health without confounding the influence of ultraviolet and infrared wavelengths.

Omalizumab treatment and outcomes in Chinese patients with chronic spontaneous urticaria, chronic inducible urticaria, or both

Background

Chronic urticaria (CU) is a common skin disorder, which can be further divided into chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU). Omalizumab is effective and safe for difficult-to-treat CSU based on clinical trials. However, there are limited data comparing the therapeutic effect of omalizumab for patients with CSU, CIndU, and CSU plus CIndU. Meanwhile, there is still no reliable predictor for treatment response or relapse. Our study was conducted to collect real-world clinical data on omalizumab treatment in patients with CSU, CIndU, and both.

Methods

This was an observational, retrospective chart review of patients with CU initiating omalizumab treatment between February 2018 and May 2020 (maximum 28 months follow-up).

Results

A total of 138 patients were included, 87 with CSU alone, 33 with different forms of CIndU, and 18 with both. A total of 87.0% (n = 120/138) of the CU patients responded to omalizumab therapy, among which 65.2% (n = 90/138) of the patients showed complete response and 21.7% (n = 30/138) of the patients showed partial response. The therapeutic effect and speed of onset of effect for omalizumab were comparable among patients with CSU, CIndU, or both. Autologous serum skin test (ASST)-positive patients were more likely to show a slow response to omalizumab therapy (P = 0.043). Non-responders had lower baseline total IgE levels (35.0 vs 121.5 kU/L, P < 0.001). The proportion of patients with low total IgE levels in non-responders was significantly higher than that of responders (61.1% vs. 14.5%, P < 0.001). Also, more non-responder patients had elevated thyroid autoantibodies than responders (50.0% vs. 23.0%, P = 0.041). The median ratio of serum IgG-anti-TPO to serum total IgE in non-responders was significantly higher compared with responders (1.22 vs. 0.09, P < 0.001). Non-responders also had shorter treatment periods (4.5 vs 6.0 months, P = 0.035) compared with responders. Two of 3 patients (67.4%, n = 29/43) experienced relapse after ceasing omalizumab therapy. These patients had longer disease durations (52.0 vs. 15.0 months, P = 0.007) and higher baseline total IgE levels (179.9 vs. 72.5 kU/L, P = 0.020) than patients who did not relapse. We reinitiated omalizumab treatment for 10 relapsed patients, all of them reported a rapid response after the first injection within the first 4 weeks of retreatment.

Conclusion

Omalizumab is highly effective in patients with difficult-to-treat CSU, CIndU, or both. Responders tend to have unique immunological features and longer treatment periods. Patients with higher baseline total IgE levels and longer disease durations are more likely to experience rapid relapse after discontinuation of omalizumab.

New phenotypes in hypersensitivity reactions to nonsteroidal anti-inflammatory drugs

PURPOSE OF REVIEW

Nonsteroidal anti-inflammatory drug (NSAID) is one of the most frequently prescribed medications in the medical field, and hypersensitivity to NSAID is a common adverse drug reaction encountered. However, NSAID hypersensitivity presents a variety of symptoms caused by diverse pharmacological and immunological mechanisms.

RECENT FINDINGS

Owing to the heterogeneity of the disease, a new concept for the classification of NSAID hypersensitivity has recently been proposed to diagnose and manage NSAID hypersensitivity for personalized treatment. Acute and delayed reactions were distinguished in this classification, and identification of symptoms and speculation of putative mechanisms help physicians make the right diagnosis. NSAID-exacerbated respiratory disease is a noticeable phenotype of NSAID hypersensitivity that involves upper airway comorbidities (chronic rhinosinusitis with nasal polyps) as well as asthmatic features. The cutaneous phenotypes of NSAID hypersensitivity occur, and cross-reactivity with other types of NSAID should be considered in establishing a proper diagnosis. Hypersensitivity to a single NSAID can present urticaria/angioedema and anaphylaxis, in which an IgE-mediated immune response is suggested to be a prime mechanism. Management of NSAID hypersensitivity reactions includes avoidance, pharmacological treatment following standard guidelines, and aspirin desensitization.

SUMMARY

The classification, diagnosis, and management of NSAID hypersensitivity should be individually reached by identifying its phenotype.

Delayed Pressure Urticaria: A Systematic Review of Treatment Options

BACKGROUND

Delayed pressure urticaria (DPU) is characterized by recurrent erythematous and often painful swelling after the skin is exposed to sustained pressure. Treatment is challenging. Antihistamines, the first-line and only approved treatment, are often not effective.

OBJECTIVE

To systematically review the treatment options for DPU.

METHOD

A literature search of electronic databases for all relevant articles published till April 29, 2019, was conducted using the search terms "delayed pressure urticaria" and "pressure urticaria." This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations.

RESULTS

Twenty-one studies (8 randomized controlled trials [RCTs], 10 retrospective cohort studies, and 3 open-label prospective studies) were included. Second-generation H₁ antihistamines (sgAHs) were effective in 3 RCTs. The combination of an sgAH and montelukast (2 RCTs) or an sgAH and theophylline (1 non-RCT) was more effective than the sgAH alone. The disease improved with omalizumab (4 non-RCTs), sulphones (3 non-RCTs), oral prednisolone (1 RCT and 2 non-RCTs), intravenous immunoglobulin (1 non-RCT), and gluten-free diet (1 non-RCT). There are no studies on updosing of antihistamines over standard dosage in DPU.

CONCLUSIONS

Overall, the quality of studies on DPU is low. Because of the lack of other evidence, antihistamines remain the first-line therapy. Updosing of sgAHs could be considered in patients with uncontrolled symptoms on the basis of the extrapolation of evidence from chronic spontaneous urticaria, even though there is no evidence of its efficacy over standard dosage. Addition of montelukast may be considered. Omalizumab or sulphones may be used in treatment-resistant patients. High-quality DPU studies should be conducted.

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.

The Real-Life Effectiveness and Safety of Omalizumab Updosing in Patients With Chronic Spontaneous Urticaria

Background:

Omalizumab is a third-line treatment for chronic spontaneous urticaria (CSU). Studies investigating the use of higher doses of omalizumab in patients unresponsive to regular doses are limited.

Objectives:

This study aims to investigate the effectiveness and safety of omalizumab 450 mg in CSU.

Methods:

A retrospective cohort study was conducted. The response to therapy was evaluated using the Urticaria Activity Score over 7 days (UAS7) and the Urticaria Control Test (UCT). Patients showing complete response (CR) (UAS7: 0-1) to omalizumab 300 mg (Group 1) and patients receiving at least 3 doses of omalizumab 450 mg (Group 2) between 2016 and 2018 were included.

Results:

A total of 72 patients (Group 1: 59; Group 2: 13) were included. In Group 2, the mean UAS7 score decreased from 18.6 to 5.1 and the mean UCT score increased from 8.6 to 12 after a mean 4.3 courses of 450 mg omalizumab treatment. Of the 13 patients in Group 2, 6 had CR and 3 had good disease control (UAS7: 2-6). The rate of patients with low baseline IgE levels (< 43 IU/mL) was significantly higher in Group 2.

Conclusions:

Higher doses of omalizumab are effective and safe in patients with CSU that is unresponsive to omalizumab 300 mg. Lower baseline total IgE levels might be used as a predictor of nonresponse to omalizumab and the need for higher doses.

Omalizumab in chronic spontaneous urticaria: steroid sparing effect

Omalizumab has been recognized to be effective in the treatment of chronic spontaneous urticaria (CSU). The Italian Medicines Agency authorizes two omalizumab courses, only for patients with CSU unresponsive to antihistamines, and this schedule may limit omalizumab use. Unfortunately, in the majority of CSU, the schedule is unsatisfactory because symptoms usually recur shortly after discontinuation of treatment. A case of a patient needing more than two treatment courses with omalizumab is reported, in order to discuss the rationale for its long-term use. Patient had needed systemic steroids almost continuously for 4 years. Two severe glucocorticoid-associated adverse events (GAEs) occurred during long-term treatment. Omalizumab 300 mg monthly was started with immediate disappearance of the urticarial lesions. Beneficial effects waned shortly after discontinuation of treatment, and further steroid use was needed. A second omalizumab course showed the same clinical pattern, with prompt response and recurrence of symptoms after suspension. Therefore, we decided to repeat the 6 months omalizumab treatment as soon as symptoms recurred, to avoid further emergency steroid treatments and GAEs. This experience suggests that long-term use of omalizumab could be useful. Evidences show that omalizumab is effective and safe for re-treatment and long-term use of responding patients after recurrence.

Update on Omalizumab for Urticaria: What's New in the Literature from Mechanisms to Clinic

PURPOSE OF REVIEW

Since omalizumab has been approved for urticaria, numerous randomized and real-life observational trials have been published. We reviewed the period January 2017-February 2018.

RECENT FINDINGS

Omalizumab is effective for the control of urticaria recalcitrant to antihistamines in different populations globally. The ratio of total serum IgE 4-week/baseline ≥2 can predict response with a high likelihood. In observational real-life trials, doses have been adjusted on an individual basis: in some populations, up to two-thirds of the patients can be controlled with 150 mg/month; however, others are still not controlled with 300 mg/month. In these, 150 mg bimonthly could be tried, before up-dosing to 450 mg/month. On the long run (up to 3 years) omalizumab kept its efficacy. In many patients, dosing intervals could be augmented (6-8 weeks, some even more). After a 12-month treatment, about 20% showed long-term remission without relapse. Some biomarkers are being detected. Adjusting omalizumab doses in urticaria patients could enhance efficacy (shortening dosing interval and/or augmenting dose) and save costs (after 12 months: extending dosing interval and/or reducing dose).

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.