Omalizumab-associated anaphylactic reactions reported between January 2007 and June 2008

Role of clinical biomarkers in predicting the effectiveness of omalizumab

OBJECTIVE

To explore whether baseline clinical biomarkers and characteristics can be used to predict the responsiveness of omalizumab.

METHODS

We retrospectively analyzed a cohort of patients with severe asthma who received omalizumab treatment and collected their baseline data and relevant laboratory examination results along with case records of omalizumab treatment responsiveness after 16 weeks. We compared the differences in variables between the group of patients that responded to omalizumab therapy and the non-responder group, and then performed univariate and multivariate logistic regression. Finally, we analyzed the difference in response rate for subgroups by selecting cut-off values for the variables using Fisher's exact probability method.

RESULTS

This retrospective, single-center observational study enrolled 32 patients with severe asthma who were prescribed daily high-dose inhaled corticosteroids and long-acting β2 receptor agonists on long-acting muscarinic receptor antagonists with or without OCS. Data on age, sex, BMI, bronchial thermoplasty, FeNO, serum total IgE, FEV1, blood eosinophils, induced sputum eosinophils, blood basophils, and complications were not significantly different between the responder and non-responder groups. In the univariate and multivariate logistic regression, all the variants were not significant, and we were unable to build a regression model. We used normal high values and the mean or median of variables as cut-off values to create patient subgroups for the variables and found no significant difference in the omalizumab response rate between the subgroups.

CONCLUSION

The responsiveness of omalizumab is not associated with pretreatment clinical biomarkers, and these biomarkers should not be used to predict the responsiveness of omalizumab.

The impact of CGRPergic monoclonal antibodies on prophylactic antimigraine therapy and potential adverse events

Migraine is a prevalent medical condition and the second most disabling neurological disorder. Regarding its pathophysiology, calcitonin gene-related peptide (CGRP) plays a key role, and, consequently, specific antimigraine pharmacotherapy has been designed to target this system. Hence, apart from the gepants, the recently developed monoclonal antibodies (mAbs) are a novel approach to treat this disorder. In this review we consider the current knowledge on the mechanisms of action, specificity, safety, and efficacy of the above mAbs as prophylactic antimigraine agents, and examine the possible adverse events that these agents may trigger. Antimigraine mAbs act as direct scavengers of CGRP (galcanezumab, fremanezumab, and eptinezumab) or against the CGRP receptor (erenumab). Due to their long half-lives, these molecules have revolutionized the prophylactic treatment of this neurovascular disorder. Moreover, because of their physicochemical properties, these agents are hepato-friendly and do not cross the blood-brain barrier (highlighting the relevance of peripheral mechanisms in migraine). Nevertheless, apart from potential cardiovascular side effects, the interaction with AMY₁ receptors and immunogenicity induced by autoantibodies against mAbs could be a concern for the safety of long-term treatment with these molecules.

Effects of omalizumab therapy on peripheral nerve functions: short observational study

Introduction

Peripheral neuropathy (PN) is a common neurological condition causing symmetrical and diffuse damage in nerves. The etiology of PN includes systemic diseases, toxic exposure, medications, infections, and hereditary diseases. Omalizumab is a humanized monoclonal anti-IgE antibody that exerts its activity by binding to free IgE in circulation.

Aim

To investigate the relationship between omalizumab and peripheral neuropathy.

Material and methods

The study included 30 patients who underwent omalizumab therapy (Xolair) due to the diagnosis of chronic urticaria. A detailed neurological and physical examination was performed in each patient both before and 3 months after the therapy. Electrophysiological examination was also performed using a Medelec Synergy instrument.

Results

The 30 patients included 8 (26.7%) men and 22 (73.3%) women with a mean age of 37.5 ±14.14 years. No serious side effect of the medication was detected in any patient although local wound irritation occurred in 3 (10%) patients. Moreover, no change occurred in the pre-treatment Neuropathy Symptom Score (NSS) or Neurological Disability Score (NDS) of the patients and no pathological values that could result in neuropathy were observed during motor/sensory nerve conduction. However, significant changes were detected in the sensory and motor components of the nerves with regards to pre- and post-treatment values.

Conclusions

Omalizumab therapy caused no peripheral neuropathy in any of our patients but altered the latency, amplitude, and velocity values of the peripheral nerves.

The safety of monoclonal antibodies in asthma

INTRODUCTION

In the last two decades the knowledge of the mechanisms of the inflammatory processes underlying asthma rapidly evolved, several key mediators (cytokines and receptors) were identified, and the laboratory techniques have allowed us to synthesize monoclonal antibodies highly specific for those target molecules. Nowadays, many biological agents are investigated in asthma (with anti IgE being the only commercially available). The clinical efficacy of some biologics was demonstrated in many cases, however, the safety issue has progressively emerged and has been recognized as a crucial aspect.

AREAS COVERED

We summarized the currently available knowledge on the safety and side effects of biologics in asthma, as derived by reviews, meta analyses and clinical trials. PubMed was searched with the terms anti IL-x [AND] safety [OR] side effects, within the categories "clinical trial", meta-analysis" and "review". Case reports were excluded. The authors collegially selected the relevant entries to be included.

EXPERT OPINION

Overall, the safety of most of the investigated agents seems to be satisfactory, a certain risk of side effects remains present, and is variable for the different molecules. Thus caution must be paid in evaluating the risk to benefit ratio. Specific biomarkers to predict the response to each biological are urgently needed to improve the safety profile.

Omalizumab and hypersensitivity reactions

PURPOSE OF REVIEW

Omalizumab, a monoclonal anti-IgE antibody, is currently indicated for the treatment of moderate-to-severe allergic asthma. We have reviewed the published studies and case reports of off-label omalizumab use in the prevention of IgE-mediated hypersensitivity reactions of various causes. Additionally, we have reviewed anaphylaxis associated with omalizumab treatment.

RECENT FINDINGS

Many case reports and smaller studies have reported the efficacy of omalizumab in the prevention of various hypersensitivity and anaphylactic reactions with or without known trigger. One randomized study has showed partial improvement in the tolerance of peanuts in peanut-allergic patients with anti-IgE therapy. Furthermore, several randomized, placebo-controlled studies and case reports have demonstrated that omalizumab in combination with allergen or venom immunotherapy decreases the incidence of systemic hypersensitivity reactions and may improve the clinical outcomes. Finally, review of the data documents low risk of anaphylaxis with omalizumab use, with one study demonstrating successful desensitization to this medication.

SUMMARY

The available studies indicate that omalizumab is effective and well tolerated in decreasing hypersensitivity reactions associated with allergen immunotherapy in patients with allergic rhinitis and mild-to-moderate asthma. Additionally, omalizumab may represent a promising therapy of anaphylaxis with or without known trigger, which should be further investigated with randomized studies. Moreover, additional research is needed to elucidate the mechanism of anaphylaxis with the medication itself.

Characteristics of anaphylaxis-inducing IgG immune complexes triggering murine passive systemic anaphylaxis

BACKGROUND

With the broad and increasing application of therapeutic monoclonal antibodies (mAbs) in clinical settings, IgG-induced allergic reactions, including passive systemic anaphylaxis (PSA), have attracted significant attention. However, it is not clear which types of IgG mAb-antigen complexes or IgG aggregates formed by antigen binding can trigger PSA, as not all immune complexes (ICs) are capable of triggering PSA. Here, we characterise mAb-antigen complexes capable of inducing murine PSA to evaluate and predict which ICs are able to induce PSA.

METHODS

Thirty-six combinatory reactions with eight antigens and 27 corresponding mAbs were used to trigger PSA, which was defined by rectal temperature. Sandwich ELISA, passive cutaneous anaphylaxis (PCA) induction and flow cytometry analysis of CD16/32 (FcγRIII/II) expression were used to characterise the ICs. The dynamic concentrations of antigen in the peripheral blood were measured by ELISA.

RESULTS

Only 14 of the 36 ICs could trigger PSA and thus be termed anaphylaxis-inducing immune complexes (Ai-ICs). The Ai-ICs could be characterised by constructing sandwich ELISA, inducing PCA and down-regulating CD16/32 (FcγRIII/II) expression on blood neutrophils in vitro and in vivo. Additionally, the occurrence and severity of PSA was found to be associated with the instantaneous concentration of antigen in the peripheral blood in the presence of antibody.

CONCLUSIONS

Only Ai-ICs, not all ICs, could trigger IgG-mediated PSA, which could be characterised by the above simple methods. The occurrence and severity of PSA was associated with the instantaneous concentration of antigen in the peripheral blood in the presence of antibody.

Allergic rhinitis and asthma: celebrating 100 years of immunotherapy

Since Noon first described allergen immunotherapy a century ago the basic premise of subcutaneous injections (SCIT) of relevant aeroallergens to induce clinical tolerance has remained true [1]. Indeed, allergen immunotherapy did not change dramatically over the first 75 years, but over the past 25 years there have been a number of important advancements leading to newer approaches and novel formulations. Here we review the top 50 articles published in the past 2 years on allergens, environmental control, and immunotherapy for asthma and allergic rhinitis and the use of immunomodulators in allergic disease.

Therapeutic strategies to reduce asthma exacerbations

Asthma exacerbations can occur in patients with all degrees of asthma severity. They generally develop over 5 to 7 days and are most often initiated by an upper respiratory tract infection (usually with human rhinovirus) or by environmental allergen exposure in atopic subjects. Inhaled corticosteroids (ICSs) taken on a regular basis are very effective in reducing the risk of asthma exacerbations, and the combination of ICSs and long-acting inhaled β₂-agonists further reduces this risk. In addition, use of the combination of the ICS budesonide and the long-acting inhaled β₂-agonist formoterol, both as maintenance asthma treatment and also as rescue treatment (instead of a short-acting inhaled β₂-agonist), has a significant further beneficial effect on asthma exacerbation risk. Other therapies that have been demonstrated to reduce severe asthma exacerbations are leukotriene receptor antagonists, which have been demonstrated to be effective most consistently in this regard in children, and anti-IgE mAbs, which are effective in subjects with difficult-to-treat allergic asthma. Approximately 50% of severe asthma exacerbations are eosinophilic in nature, whereas many of the remaining are neutrophilic. Several studies have demonstrated that making asthma treatment decisions based on minimizing airway eosinophil numbers (measured in induced sputum) can reduce the risks of severe exacerbations. In addition, treatment of patients with severe asthma with an anti-IL-5 mAb also reduces the number of severe asthma exacerbations, demonstrating a central role of eosinophils in many exacerbations.

Immunotherapy for allergies and asthma: present and future

Allergen immunotherapy (IT) is a proven approach for treating allergic rhinitis and allergic asthma that has been practiced since 1911 and has undergone significant development in the past two decades. As currently practiced, IT involves subcutaneous or sublingual administration of allergens, both methods of which have been extensively investigated. In addition to allergen IT, a number of additional nonspecific IT approaches are being used or are in phase II/phase III clinical trials, which may be available in clinics within the next one to three years. Such therapies include anti-IgE antibodies and the soluble IL-4 receptor. Other experimental IT approaches are at the preclinical research stage and may proceed to clinical trials and the clinic within the next five to ten years. This review discusses the pros and cons of recent developments in both currently practiced and experimental IT approaches.