Sustained safety and efficacy of ligelizumab in patients with chronic spontaneous urticaria: A one-year extension study

New biologics for food allergy

PURPOSE OF REVIEW

This review aims to explore role of emerging biologics, including ligelizumab, UB-221, dupilumab, and antialarmins, in food allergy management. With a focus on recent developments, we evaluate their promise in mitigating adverse events during oral immunotherapy (OIT), reducing allergic reactions, and addressing the limitations of current therapeutic options.

RECENT FINDINGS

Antiimmunoglobulin E mAbs, exemplified by omalizumab, demonstrate efficacy in desensitization and safety improvement during multiallergen OIT. Next-generation antibodies like ligelizumab and UB-221 exhibit enhanced potency and unique mechanisms, holding promise for food allergy treatment. Dupilumab, targeting IL-4 receptor alpha, presents potential benefits in decreasing allergen-specific IgE and modifying the atopic march. Exploration of antialarmins, specifically anti-IL-33 (etokimab) and anti-TSLP (tezepelumab), reveals encouraging results, with etokimab showing early success in peanut allergy trials.

SUMMARY

Biologics hold promising potential for food allergy treatment. Tailoring therapeutic approaches based on shared decision-making becomes pivotal. While omalizumab remains a significant option, next-generation anti-IgE antibodies and agents targeting alarmins exhibit unique strengths. Dupilumab, despite limited success as monotherapy, shows promise as an adjunct for OIT. Careful consideration of treatment goals, patient preferences, and the evolving landscape of biologics will shape future clinical practice, offering allergists an expanded toolbox for personalized food allergy management.

Mapping the intellectual structure of the research of omalizumab in chronic spontaneous urticaria: A bibliometric analysis

Background

The guidelines for treating chronic spontaneous urticaria (CSU) recommend using the IgE-targeted biologic omalizumab in patients with antihistamine-refractory disease.

Objective

Our aim was to present a bibliometric review of publications related to omalizumab and CSU over the past 2 decades.

Methods

Relevant publications from 2003 to 2022 were extracted from the Science Citation Index-Expanded (SCI-EXPANDED) database in the Web of Science Core Collection database as of January 8, 2023. We utilized CiteSpace (version 6.1.R3), VOSviewer (version 1.6.18), and the R package (version 4.2.1) to analyze and visualize the data. The R package bibliometrix (version 4.2.1) was also used.

Results

Between 2003 and 2022, a total of 566 articles on omalizumab and CSU were published. Since 2014, there has been a rapid increase in publication output. According to the collaboration network, the most influential country, institute, and scholar were the United States, Charité Universitätsmedizin Berlin, and Marcus Maurer, respectively. The study identified the Journal of Allergy and Clinical Immunology: In Practice as the most productive journal and the Journal of Allergy and Clinical Immunology as the most cocited journal. The analysis of key words revealed the presence of high-frequency terms such as angioedema, IgE, treatment, anti-IgE, asthma, and atopic dermatitis. Moreover, recent studies in this area have concentrated mainly on biomarkers, dupilumab, and coronavirus 2019 (COVID-19).

Conclusion

There has been a growing interest in the use of omalizumab in CSU in recent years. The current trending topics in this research are the identification of biomarkers and the development of new mAbs for the treatment of CSU.

Targeted therapy for immune mediated skin diseases. What should a dermatologist know?

BACKGROUND

Molecularly targeted therapies, such as monoclonal antibodies (mAbs) and Janus Kinase inhibitors (JAKis), have emerged as essential tools in the treatment of dermatological diseases. These therapies modulate the immune system through specific signaling pathways, providing effective alternatives to traditional systemic immunosuppressive agents. This review aims to provide an updated summary of targeted immune therapies for inflammatory skin diseases, considering their pathophysiology, efficacy, dosage, and safety profiles.

METHODS

The review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. A systematic search was conducted on PubMed over the past 10 years, focusing on randomized clinical trials, case reports, and case series related to targeted immune therapies in dermatology. Eligibility criteria were applied, and data were extracted from each study, including citation data, study design, and results.

RESULTS

We identified 1360 non-duplicate articles with the initial search strategy. Title and abstract review excluded 1150, while a full-text review excluded an additional 50 articles. The review included 143 studies published between 2012 and 2022, highlighting 39 drugs currently under investigation or in use for managing inflammatory skin diseases.

STUDY LIMITATIONS

The heterogeneity of summarized information limits this review. Some recommendations originated from data from clinical trials, while others relied on retrospective analyses and small case series. Recommendations will likely be updated as new results emerge.

CONCLUSION

Targeted therapies have revolutionized the treatment of chronic skin diseases, offering new options for patients unresponsive to standard treatments. Paradoxical reactions are rarely observed. Further studies are needed to fully understand the mechanisms and nature of these therapies. Overall, targeted immune therapies in dermatology represent a promising development, significantly improving the quality of life for patients with chronic inflammatory skin diseases.

Efficacy and safety of ligelizumab in adults and adolescents with chronic spontaneous urticaria: results of two phase 3 randomised controlled trials

BACKGROUND

Many patients with chronic spontaneous urticaria (CSU) do not achieve complete control of their symptoms with current available treatments. In a dose-finding phase 2b study, ligelizumab improved urticaria symptoms in patients with H1-antihistamine (H1-AH) refractory CSU. Here, we report the efficacy and safety outcomes from two ligelizumab phase 3 studies.

METHODS

PEARL-1 and PEARL-2 were identically designed randomised, double-blind, active-controlled and placebo-controlled parallel-group studies. Patients aged 12 years or older with moderate-to-severe H1-AH refractory CSU were recruited from 347 sites in 46 countries and randomly allocated in a 3:3:3:1 ratio via Interactive Response Technology to 72 mg ligelizumab, 120 mg ligelizumab, 300 mg omalizumab, or placebo, dosed every 4 weeks, for 52 weeks. Patients allocated to placebo received 120 mg ligelizumab from week 24. The primary endpoint was change-from-baseline (CFB) in weekly Urticaria Activity Score (UAS7) at week 12, and was analysed in all eligible adult patients according to the treatment assigned at random allocation. Safety was assessed throughout the study in all patients who received at least one dose of the study drug. The studies were registered with ClinicalTrials.gov, NCT03580369 (PEARL-1) and NCT03580356 (PEARL-2). Both trials are now complete.

FINDINGS

Between Oct 17, 2018, and Oct 26, 2021, 2057 adult patients were randomly allocated across both studies (72 mg ligelizumab n=614; 120 mg ligelizumab n=616; 300 mg omalizumab n=618, and placebo n=209). A total of 1480 (72%) of 2057 were female, and 577 (28%) of 2057 were male. Mean UAS7 at baseline across study groups ranged from 29·37 to 31·10. At week 12, estimated treatment differences in mean CFB-UAS7 were as follows: for 72 mg ligelizumab versus placebo, -8·0 (95% CI -10·6 to -5·4; PEARL-1), -10·0 (-12·6 to -7·4; PEARL-2); 72 mg ligelizumab versus omalizumab 0·7 (-1·2 to 2·5; PEARL-1), 0·4 (-1·4 to 2·2; PEARL-2); 120 mg ligelizumab versus placebo -8·0 (-10·5 to -5·4; PEARL-1), -11·1 (-13·7 to -8·5; PEARL-2); 120 mg ligelizumab versus omalizumab 0·7 (-1·1 to 2·5; PEARL-1), -0·7 (-2·5 to 1·1; PEARL-2). Both doses of ligelizumab were superior to placebo (p<0·0001), but not to omalizumab, in both studies. No new safety signals were identified for ligelizumab or omalizumab.

INTERPRETATION

In the phase 3 PEARL studies, ligelizumab demonstrated superior efficacy versus placebo but not versus omalizumab. The safety profile of ligelizumab was consistent with previous studies.

FUNDING

Novartis Pharma.

Elevated baseline soluble FcεRI may be linked to early response to omalizumab treatment in chronic spontaneous urticaria

BACKGROUND

Omalizumab, an anti-IgE monoclonal antibody, is an effective treatment in chronic spontaneous urticaria (CSU). Predictors of fast and good response for omalizumab treatment have not yet been identified and characterized.

OBJECTIVE

To evaluate whether soluble FcεRI (sFcεRI), a marker of IgE-mediated mast cell activation, predicts the time of response to omalizumab in CSU.

METHODS

Sera of 67 CSU patients were obtained before omalizumab treatment and analysed for sFcεRI levels by ELISA (2 ng/mL was used as cut-off for elevated sFcɛRI). Treatment response during the first 4 weeks was assessed with the urticaria activity score (UAS7), urticaria control test (UCT) and the rolling UAS7 (rUAS7).

RESULTS

Elevated pre-treatment sFcɛRI levels were detected in more than 70% of patients with completely controlled disease (UCT = 16) and well-controlled disease (UCT = 12-15) and were significantly associated with disease control (χ2  = 4.94, p < 0.05). More than half of the patients (14/25) with low levels had poor disease control (UCT < 12). Of the patients who achieved complete and marked UAS7 response, respectively, 75% and 63% had elevated baseline sFcɛRI levels. Post-treatment UAS7 scores were lower in patients with elevated sFcɛRI levels reaching statistical significance at Week 3 (p < 0.05). Patients with elevated baseline sFcɛRI levels achieved rUAS7 ≤ 6 and = 0 earlier than those with lower levels (Days 9 vs. 13 and Days 12 vs. 14, respectively).

CONCLUSION

Elevated sFcεRI serum levels predict early and good response to treatment with omalizumab, which may help to better design treatment options for CSU patients.

Approach to Idiopathic Anaphylaxis in Adolescents

Anaphylaxis is a potentially-life threatening condition. Adolescents are particularly vulnerable due to increased risk-taking behaviors, poor disease management, and minimized perception of risk. Although most anaphylaxis can be attributed to food, drug, or venom allergy via a detailed history and confirmatory studies, in nearly 1 in 5 cases, the cause may not be obvious. Clinical differentials including rare allergens, cofactors, mast-cell disorders, and mimic disorders can increase the likelihood of discovering of the cause of anaphylaxis.

Autoreactive IgE: Pathogenic role and therapeutic target in autoimmune diseases

Autoimmunity is the break of tolerance to self-antigens that leads to organ-specific or systemic diseases often characterized by the presence of pathogenic autoreactive antibodies (AAb) produced by plasmablast and/or plasma cells. AAb are prevalent in the general population and not systematically associated with clinical symptoms. In contrast, in some individuals, these AAb are pathogenic and drive the development of signs and symptoms of antibody-mediated autoimmune diseases (AbAID). AAb production, isotype profiles, and glycosylations are promoted by pro-inflammatory triggers linked to genetic, environmental, and hormonal parameters. Recent evidence supports a role for pathogenic AAb of the IgE isotype in a number of AbAID. Autoreactive IgE can drive the activation of mast cells, basophils, and other types of FcεRI-bearing cells and may play a role in promoting autoantibody production and other pro-inflammatory pathways. In this review, we discuss the current knowledge on the pathogenicity of autoreactive IgE in AbAID and their status as therapeutic targets. We also highlight unresolved issues including the need for assays that reproducibly quantify IgE AAbs, to validate their diagnostic and prognostic value, and to further study their pathophysiological contributions to AbAID.

The origins and longevity of IgE responses as indicated by serological and cellular studies in mice and humans

The existence of long-lived IgE antibody-secreting cells (ASC) is contentious, with the maintenance of sensitization by the continuous differentiation of short-lived IgE+ ASC a possibility. Here, we review the epidemiological profile of IgE production, and give an overview of recent discoveries made on the mechanisms regulating IgE production from mouse models. Together, these data suggest that for most individuals, in most IgE-associated diseases, IgE+ ASC are largely short-lived cells. A subpopulation of IgE+ ASC in humans is likely to survive for tens of months, although due to autonomous IgE B cell receptor (BCR) signaling and antigen-driven IgE+ ASC apoptosis, in general IgE+ ASC probably do not persist for the decades that other ASC are inferred to do. We also report on recently identified memory B cell transcriptional subtypes that are the likely source of IgE in ongoing responses, highlighting the probable importance of IL-4Rα in their regulation. We suggest the field should look at dupilumab and other drugs that prohibit IgE+ ASC production as being effective treatments for IgE-mediated aspects of disease in most individuals.

Type 2 chronic inflammatory diseases: targets, therapies and unmet needs

Over the past two decades, significant progress in understanding of the pathogenesis of type 2 chronic inflammatory diseases has enabled the identification of compounds for more than 20 novel targets, which are approved or at various stages of development, finally facilitating a more targeted approach for the treatment of these disorders. Most of these newly identified pathogenic drivers of type 2 inflammation and their corresponding treatments are related to mast cells, eosinophils, T cells, B cells, epithelial cells and sensory nerves. Epithelial barrier defects and dysbiotic microbiomes represent exciting future drug targets for chronic type 2 inflammatory conditions. Here, we review common targets, current treatments and emerging therapies for the treatment of five major type 2 chronic inflammatory diseases - atopic dermatitis, chronic prurigo, chronic urticaria, asthma and chronic rhinosinusitis with nasal polyps - with a high need for targeted therapies. Unmet needs and future directions in the field are discussed.

Time Course of Priming Effect of TF Inducers on Synergistic TF Expression and Intra-Cellular Gap Formation of Human Vascular Endothelial Cells via the Extrinsic Coagulation Cascade

Chronic spontaneous urticaria (CSU) is characterized by daily recurring wheal and flare with itch for more than 6 weeks. The extrinsic coagulation system has been shown to be activated in correlation with CSU severity. We have reported that tissue factor (TF), a trigger of the extrinsic coagulation cascade, is synergistically expressed on vascular endothelial cells by simultaneous stimulation with TF inducers (TFI), followed by activation of the extrinsic coagulation cascade and hyper permeability in vitro. However, vascular endothelial cells are not likely to be simultaneously stimulated by multiple TFIs under physiological conditions. Therefore, in order to know whether sequential, rather than simultaneous, stimuli with interval may induce synergistic activation of TF, we investigated the time course of the priming effects of each TFI for synergistic TF expression in vascular endothelial cells (HUVECs). We stimulated HUVECs with a TFI (first stimulation) and then stimulated cells with another TFI at indicated time points (second stimulation) and detected TF expression and activity. The TF expression induced by simultaneous stimulation diminished in a few hours. However, both synergistic enhancement of TF expression and activation level of the coagulation cascade were detected even when the second stimulation was added 18 or 22 h after the first stimulation. Thus, the priming effect of TFI for synergistic TF expression may persist for a half day or longer.

Research Advances in Mast Cell Biology and Their Translation Into Novel Therapies for Anaphylaxis

Anaphylaxis is an acute, potentially life-threatening systemic allergic reaction for which there are no known reliable preventative therapies. Its primary cell mediator, the mast cell, has several pathophysiologic roles and functions in IgE-mediated reactions that continue to be poorly understood. Recent advances in the understanding of allergic mechanisms have identified novel targets for inhibiting mast cell function and activation. The prevention of anaphylaxis is within reach with new drugs that could modulate immune tolerance, mast cell proliferation and differentiation, and IgE regulation and production. Several US Food and Drug Administration-approved drugs for chronic urticaria, mastocytosis, and cancer are also being repurposed to prevent anaphylaxis. New therapeutics have not only shown promise in potential efficacy for preventing IgE-mediated reactions, but in some cases, they are able to inform us about mast cell mechanisms in vivo. This review summarizes the most recent advances in the treatment of anaphylaxis that have arisen from new pharmacologic tools and our current understanding of mast cell biology.

Current and Emerging Therapies for Chronic Spontaneous Urticaria: A Narrative Review

Chronic spontaneous urticaria (CSU) is a condition in which wheals, angioedema, and pruritus occur spontaneously and recurrently for at least 6 weeks. The etiology of this disease is partially dependent on production of autoantibodies that activate and recruit inflammatory cells. Although the wheals can resolve within 24 h, symptoms have a significant detrimental impact on the quality of life of these patients. Standard therapy for CSU includes second-generation antihistamines and omalizumab. However, many patients tend to be refractory to these therapies. Available treatments such as cyclosporine, dapsone, dupilumab, and tumor necrosis factor alpha (TNFa) inhibitors have been used with success in some cases. Furthermore, various biologics and other novel drugs have emerged as potential treatments for this condition, and many more are currently under investigation in randomized clinical trials.

Aiming to IgE: Drug development in allergic diseases

The incidence of allergic disease significantly increases in recent decades, causing it become a major public health problem all over the world. The common allergic diseases such as allergic dermatitis, allergy rhinitis, allergic asthma and food allergy are mediated, at least in part, by immunoglobulin E (IgE), and so IgE acts as a central role in allergic diseases. IgE can interact with its high-affinity receptor (FcεRⅠ) which is primarily expressed on tissue-resident mast cells and circulating basophils, initiating intracellular signal transduction and then causing the activation and degranulation of mast cells and basophils. On the other hand, IgE interaction with its low-affinity receptor (CD23), can regulate various IgE-mediated immune responses including IgE-allergen complex presentation, IgE synthesis, the growth and differentiation of both B and T cells, and the secretion of pro-inflammatory mediators. With the deeper mechanism research for allergic diseases, new therapeutic strategies for interfering IgE are developed and receive a great attention. In this review, we summarize a current profile of therapeutic strategies for interfering IgE in allergic diseases. Besides, we suggest that targeting memory B cells (including long-lived plasma cells and (or) IgE⁺ memory B cells) may help to completely control allergic diseases, and highlight that the development of drugs synergistically aiming to multiple targets can be a better choice for improving treatment efficacy which results from allergic diseases as the systemic disorders caused by an impaired immune system.

Self-reactive IgE and anti-IgE therapy in autoimmune diseases

Growing evidence indicates the pathogenic role of autoreactive IgE in autoimmune diseases. Incidence of autoimmune and allergic diseases in the industrialized countries is consistently icreasing, thus leading to concerted efforts to comprehend the regulation of IgE-mediated mechanisms. The first reports of a presence of IgE autoantibodies in patients with autoimmune diseases have been published a long time ago, and it is now recognized that self-reactive IgE can mediate inflammatory response in bullous pemhigoid, systemic lupus erythematosus, chronic urticaria, and atopic dermatitis. The advances in understanding the pathomechanisms of these disorders brought to a successful use of anti-IgE strategies in their management. The present review discusses the current state of knowledge on the IgE-mediated autoimmunity and anti-IgE treatment, and pave the way for further exploration of the subject.

Utilizing Biologics in Drug Desensitization

PURPOSE OF REVIEW

The purpose of this literature review was to review the latest advancements with biologics in rapid drug desensitization. Our methodology was to highlight both desensitization to biologics themselves and the use of biologics in desensitization to both biologic and nonbiologic drugs.

RECENT FINDINGS

Biologics are a vast category of drugs that include monoclonal antibodies, nanobodies, modern vaccinations, and even hormones. Desensitization to biologics can be safely performed through standardized procedure. Biomarkers are used both in vitro and in vivo to help identify and classify hypersensitivity reactions. Hypersensitivity reactions to the mRNA vaccinations against SARS-CoV-2 present their own unique challenges to management. There are specific excipients in monoclonal antibodies that are thought to be responsible for many of their hypersensitivity reactions. Certain biologics can even be used to assist in desensitization to other drugs. Rapid drug desensitization is a standardized procedure that may be able to help many patients who have experienced hypersensitivity reactions to biologics and would best be treated with them to continue to receive them. Biologic drugs have opened a new era in medicine for the prevention and treatment of infectious diseases, cancer, and inflammatory diseases. Hypersensitivity reactions to biologics are quite common. This literature review presents the latest advancements in our understanding of hypersensitivity reactions to biologics, how rapid drug desensitization can be used to continue therapy despite history of hypersensitivity, and how biologics themselves can be used to aid in desensitization itself.

Ligelizumab impairs IgE ‐binding to plasmacytoid dendritic cells more potently than omalizumab and restores IFN ‐α production and FOXP3 + Treg generation

BACKGROUND

Ligelizumab is an anti-IgE monoclonal antibody binding IgE with higher affinity than omalizumab that is under clinical investigation for several IgE-mediated diseases. We previously showed that omalizumab removes IgE bound to FcεRI on plasmacytoid dendritic cells (pDCs) and restores their ability to produce IFN-α and regulatory T cells (Tregs). The aim of this work is to investigate the capacity of ligelizumab to regulate functional properties of pDCs in comparison with omalizumab.

METHODS

pDCs were isolated from atopic donors and IgE was detached from FcεRI on pDCs with designed ankyrin repeat protein (DARPin) bi53-79. pDCs were resensitized with IgE alone or in the presence of ligelizumab or omalizumab prior to IgE-FcεRI crosslinking and Toll-like receptor 9 (TLR9) stimulation. Flow cytometry, ELISA, coculture experiments and intranuclear staining were performed to determine cytokine production and Treg generation. An antigen-specific model of resensitization and IgE-crosslinking was also performed.

RESULTS

The levels of serum total free IgE show a non-linear positive correlation with the frequency of IgE⁺ pDCs displaying IgE bound to FcεRI within the 43 individual donors included in the study. Ligelizumab displays stronger capacity than omalizumab to block the binding of free IgE to FcεRI on human pDCs, resulting in a greater restoration of TLR9-L-induced IFN-α production. Ligelizumab also restores the ability of pDCs to generate FOXP3⁺ Tregs as previously reported for omalizumab.

CONCLUSIONS

The uncovered novel molecular mechanisms of ligelizumab to regulate functional properties of pDCs from atopic donors might have important clinical implications for anti-IgE treatments in different IgE-mediated diseases.

Ligelizumab improves angioedema, disease severity and quality-of-life in patients with chronic spontaneous urticaria

Background

Disease burden is particularly high in Chronic Spontaneous Urticaria (CSU) patients with angioedema, and patients whose signs and symptoms are inadequately controlled by H₁-antihistamines need new treatment options. Here we report an exploratory analysis, from the ligelizumab Phase 2b study, investigating angioedema occurrence in patients with CSU and describe the changes in angioedema following treatment with ligelizumab, omalizumab, or placebo.

Methods

Data from the ligelizumab Phase 2b core (ligelizumab 72 mg, 240 mg, omalizumab 300 mg and placebo) and extension study (ligelizumab 240 mg) were used. Changes in Weekly Angioedema Activity Score (AAS7), the Dermatology Life Quality Index (DLQI), and Weekly Urticaria Activity Score (UAS7) among each time point were analyzed for each treatment arm.

Results

From a total of 297 patients analyzed, 165 (55.6%) reported angioedema occurrence at baseline, with mean AAS7 ranging 30.6—42.2 across treatment arms. At Week 12 of the core study 87.5%, 84.6%, 75.0%, and 61.0% of patients were angioedema free for ligelizumab 72 mg, 240 mg, omalizumab 300 mg, and placebo arms, respectively. In CSU patients with angioedema at baseline, the largest change from baseline in AAS7 score was observed with ligelizumab 72 mg (−31.9) at week 16 in the core study. Patients with angioedema had a higher mean DLQI at baseline (14.9—16.1) vs. patients without angioedema (10.6—12.0). In patients with angioedema, low AAS7 was significantly associated with complete response on UAS7 (UAS7 = 0) and complete normalization of DLQI (DLQI 0—1).

Conclusion

In the Phase 2b study, ligelizumab effectively reduced angioedema and urticaria symptoms, and improve health related quality of life in patients with moderate-to-severe CSU.

Clinicaltrails.gov NCT number

NCT02477332; NCT02649218.

The rationale for development of ligelizumab in food allergy

Food allergy (FA) is a growing healthcare problem worldwide and the rising prevalence in many countries can be attributed to lifestyle, environmental, and nutritional changes. Immunoglobulin E (IgE)-mediated FA is the most common form of FA affecting approximately 3%-10% of adults and 8% of children across the globe. Food allergen-induced immediate hypersensitivity reactions mediated by IgE and high-affinity IgE receptor (FcεRI) complexes on mast cells and basophils are a major hallmark of the disease. FA can affect several aspects of health-related quality of life and impose a substantial financial burden on patients and healthcare systems. Although currently there is one United States Food and Drug Administration (FDA) and European Medicines Agency (EMA)-approved treatment for peanut allergy (Palforzia), the main treatment approaches are based on allergen avoidance and symptom management. Thus, there is an urgent need for more effective and ideally disease-modifying strategies. Given the crucial role of IgE in FA, anti-IgE monoclonal antibodies are considered promising therapeutic agents. Talizumab was the first humanized anti-IgE antibody to demonstrate substantial protection against allergic reactions from accidental peanut exposure by substantially increasing the peanut reactivity threshold on oral food challenge. However, development of talizumab was discontinued and further trials were performed using omalizumab. In double-blind, Phase 2, placebo-controlled trials in patients with multi-FAs, sustained dosing with omalizumab, or omalizumab in combination with oral immunotherapy, enabled rapid desensitization to multiple trigger foods. In this review, we describe the development of ligelizumab (a derivative of talizumab), a next generation, humanized monoclonal anti-IgE antibody, its existing clinical evidence, and its potential in the management of FA. When compared with omalizumab, ligelizumab binds with ∼88-fold higher affinity for human IgE and recognizes a different epitope that substantially overlaps with the binding site of FcεRI. These properties translate into a high potency to block IgE/FcεRI signaling in both in vitro and in vivo studies. Given its efficient suppression of IgE levels, good safety and pharmacokinetic/pharmacodynamic profile, ligelizumab clearly warrants further studies for the potential management of FA.

Pathophysiology, Diagnosis, and Management of Chronic Spontaneous Urticaria: A Literature Review

Chronic spontaneous urticaria (CSU) is characterized by recurring wheals that last 6 weeks or longer without an identifiable cause. The estimated point prevalence of CSU worldwide is 1%. Furthermore, it has a significant impact on quality of life in both adults and pediatric patients and their families. Although it is most often a self-limited disease, some patients have urticaria refractory to first-line treatment: second-generation H1 antihistamines. In these patients, the use of targeted monoclonal antibodies is necessary. While omalizumab is the only Food and Drug Administration-approved monoclonal antibody for CSU, others, including ligelizumab, dupilumab, benralizumab, and several orally administered Bruton's tyrosine kinase inhibitors, are also promising therapeutics for reducing the morbidity of CSU. Novel therapies, among others discussed here, are rapidly being developed with new trials and therapeutics being released nearly monthly. Thus, we performed a scoping literature review of randomized controlled trials studying targeted therapies for CSU. We also discuss the pathophysiology, diagnosis, prognosis, and future research directions in CSU.

Monoclonal Antibodies in Treating Chronic Spontaneous Urticaria: New Drugs for an Old Disease

Background: H1-antihistamines (H1AH) represent the current mainstay of treatment for chronic spontaneous urticaria (CSU). However, the response to H1AH is often unsatisfactory, even with increased doses. Therefore, guidelines recommend the use of omalizumab as an add-on treatment in refractory CSU. This paved the way for the investigation of targeted therapies, such as monoclonal antibodies (mAbs), in CSU. Methods: A literature review was conducted including papers published between 2009 and 2022 and ongoing trials about the efficacy and safety of mAbs as treatment for CSU. Results: Twenty-nine articles, a trial with preliminary results, and seventeen ongoing or completed clinical trials on the use of mAbs in CSU were included. Randomized controlled trials (RCTs), meta-analysis, and real-life studies have proven the effectiveness and safety of omalizumab as a third-line treatment in refractory CSU. However, a percentage of patients remain unresponsive to omalizumab. Therefore, other mAbs, targeting different pathways, have been used off-label in case series and others are under investigation in RCTs. Most of them have showed promising results. Conclusions: Omalizumab remains the best choice to treat refractory CSU. Although results from other mAbs seem to be encouraging to achieve symptom control in refractory CSU, thus improving patients’ QoL, RCTs are needed to confirm their effectiveness and safety.

Emerging treatments for chronic urticaria

INTRODUCTION

Across the globe, chronic urticaria (CU), i.e. chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CINDU), is common, long-persisting and difficult to manage. Still, at least one-fifth is not sufficiently controlled by guideline-recommended treatment with H1-antihistamines and add-on therapy with the anti-IgE monoclonal antibody omalizumab.

AREAS COVERED

Using PubMed, ClinicalTrials.gov, Congress websites, and websites of the manufacturers, this review explored the pipeline, namely anti-IgE-, anti-cytokine-, anti-receptor biologics, and small molecules, in clinical development for CU.

EXPERT OPINION

The CU pipeline is promising. While three omalizumab biosimilars are investigated, the assumed early approval of ligelizumab will expand the effective and safe anti-IgE approach observed with omalizumab. For other anti-IgEs like UB-221, the development is behind. Data are too limited so far to clearly define the role of anti-cytokine and anti-cytokine receptor biologics such as dupilumab, tezepelumab, mepolizumab, benralizumab, and CDX-0159, of which only dupilumab is actually investigated in phase 3. Among three selective oral BTK inhibitors, remibrutinib, rilzabrutinib, and fenebrutinib, the development of remibrutinib is most advanced (phase 3). As the pipeline addresses different targets, study results will give deeper insights into the pathomechanisms of CU. Hopefully, in the next future additional approved and also more targeted approaches will be available.

Ligelizumab improves sleep interference and disease burden in patients with chronic spontaneous urticaria

Background

Chronic spontaneous urticaria (CSU) negatively impacts patients' sleep, thereby reducing health‐related quality of life (HRQoL). Half of patients with inadequately controlled CSU report sleep interference often or every night, which can lead to depression, anxiety, social, and work‐related problems.

Methods

This randomized, double‐blind, placebo‐controlled Phase 2b core study (NCT02477332) included adult patients ≥18 years with moderate to severe CSU inadequately controlled with H₁‐antihistamines. The current analysis includes patients randomized to receive ligelizumab 72 or 240 mg, omalizumab 300 mg or placebo every 4 weeks (q4w) for five injections over 20 weeks with treatment‐free follow‐up for 24 weeks. Patients could enter the open‐label extension study (NCT02649218) from Week 32 onwards if their weekly urticaria activity score was ≥12, which included an open‐label treatment (52 weeks of ligelizumab 240 mg q4w) and a 48‐week post‐treatment follow‐up. Weekly Sleep Interference Scores (SIS7, range 0 [no interference]–21 [substantial interference]), Weekly Activity Interference Score (AIS7), Dermatology Life Quality Index (DLQI) scores, and Overall Work Impairment were assessed.

Results

Mean baseline SIS7 scores were balanced between the treatment arms for ligelizumab 72 mg (n = 84) and 240 mg (n = 85), omalizumab 300 mg (n = 85), and placebo (n = 43). By Week 12, patients experienced large improvements in sleep interference, with least square mean (standard error) changes from baseline (CFB) in SIS7 of −7.84 (0.58), −7.55 (0.61), −6.98 (0.60), and −5.85 (0.81), respectively. By Week 12, CFB in AIS7 were −8.25 (0.57), −8.25 (0.59), −7.30 (0.60), and −5.62 (0.79), DLQI scores were −9.79 (0.77), −9.93 (0.81), −8.35 (0.79), and −6.99 (1.11), and Overall Work Impairment scores were −28.96 (3.73), −30.76 (3.71), −25.74 (3.91), and −20.13 (5.10) for ligelizumab 72 and 240 mg, omalizumab 300 mg and placebo, respectively. Improvements in each patient‐reported outcome were sustained with ligelizumab 240 mg treatment during the extension study.

Conclusions

Ligelizumab showed effective and sustained responses in managing sleep interference in patients with CSU, and numerically higher responses than with omalizumab and placebo. Treating the symptoms of CSU with ligelizumab improved disease burden, HRQoL, and markedly improved sleep quality.

Regulation of Trafficking and Signaling of the High Affinity IgE Receptor by FcεRIβ and the Potential Impact of FcεRIβ Splicing in Allergic Inflammation

Mast cells are tissue-resident immune cells that function in both innate and adaptive immunity through the release of both preformed granule-stored mediators, and newly generated proinflammatory mediators that contribute to the generation of both the early and late phases of the allergic inflammatory response. Although mast cells can be activated by a vast array of mediators to contribute to homeostasis and pathophysiology in diverse settings and contexts, in this review, we will focus on the canonical setting of IgE-mediated activation and allergic inflammation. IgE-dependent activation of mast cells occurs through the high affinity IgE receptor, FcεRI, which is a multimeric receptor complex that, once crosslinked by antigen, triggers a cascade of signaling to generate a robust response in mast cells. Here, we discuss FcεRI structure and function, and describe established and emerging roles of the β subunit of FcεRI (FcεRIβ) in regulating mast cell function and FcεRI trafficking and signaling. We discuss current approaches to target IgE and FcεRI signaling and emerging approaches that could target FcεRIβ specifically. We examine how alternative splicing of FcεRIβ alters protein function and how manipulation of splicing could be employed as a therapeutic approach. Targeting FcεRI directly and/or IgE binding to FcεRI are promising approaches to therapeutics for allergic inflammation. The characteristic role of FcεRIβ in both trafficking and signaling of the FcεRI receptor complex, the specificity to IgE-mediated activation pathways, and the preferential expression in mast cells and basophils, makes FcεRIβ an excellent, but challenging, candidate for therapeutic strategies in allergy and asthma, if targeting can be realized.