Omalizumab: a review of its use in the management of allergic asthma

Therapeutic Efficacy of YH35324 on FcεRIα-Mediated Mast Cell/Basophil Activation

PURPOSE

Immunoglobulin E (IgE) induces mast cell/basophil activation by binding with FcεRIα and contributes to the development of allergic disease, in which targeting IgE has been considered an effective therapeutic strategy. YH35324 (YH) is a new hybrid protein with an extracellular domain consisting of FcεRIα, and its pharmacodynamic effect and safety were validated. This study aimed to evaluate the therapeutic potential of YH as an anti-IgE immunomodulator compared with omalizumab (Oma).

METHODS

To evaluate the in vitro efficacy of YH in human mast cells, YH was treated with various methods, and the changes were confirmed through flow cytometry, immunoblot analysis, and immunocytochemistry. To evaluate the ex vivo efficacy of YH, the expression of FcεRIα on the surface of blood basophils was measured in 64 subjects with allergic diseases by flow cytometry. Serum soluble FcεRIα, CD23, and Mas-Related G-Protein Coupled Receptor Member X2 levels were measured by enzyme-linked immunosorbent assay.

RESULTS

The YH-administered group exhibited significantly lower expression of FcεRIα on peripheral basophils compared to the Oma-administered group up to 14 days post-administration. YH directly suppressed FcεRIα expression on the surface of LAD2 cells, as it was bound to IgE-unbound FcεRIα and migrated into the cells by actin-dependent endocytosis, then was recycled by FcRn binding in the lysosome in vitro. Serum soluble FcεRIα levels were increased in the YH-administered group compared to the other groups and showed a positive correlation with serum-free IgE.

CONCLUSIONS

YH represents a new therapeutic agent for IgE-mediated allergic disease. Further studies are needed to evaluate its additional effects on the FcεRIα-mediated autoimmune mechanism.

Brazilian guideline for the use of immunobiologicals in chronic rhinosinusitis with nasal polyps ‒ 2024 update

INTRODUCTION

Biologics targeting type 2 inflammation have revolutionized the way we treat patients with Chronic Rhinosinusitis with Nasal Polyps (CRSwNP). Particularly in severe and difficult-to-control cases, these drugs have provided a new reality for these patients, allowing for the effective and safe treatment of extensive diseases that were not completely managed with the typical strategy of surgery and topical medications.

OBJECTIVES

The experience achieved with the approval of these medications by ANVISA for use in CRSwNP and the knowledge obtained regarding outcomes, adverse effects, and the ideal patient profile prompted the update of the previously published guideline, with a detailed review of the most recent scientific literature, the personal experiences of experts, and the adaptation to the reality of the Brazilian healthcare system, both public and private.

RESULTS

We proposed a new eligibility criterion for biologics in patients with CRSwNP based on four pillars of indication: the impact of the disease on the patient's life, whether in the presence of specific symptoms or in overall quality of life; the extent of sinonasal disease; the presence of type 2 comorbidities, considering other associated diseases that may also benefit from anti-T2 biologics, and the presence of biomarkers to define type 2 inflammation, especially those associated with worse disease prognoses.

CONCLUSIONS

This innovative and pioneering method has two major advantages. First, it ensures a comprehensive evaluation of patients; second, it is flexible, as advancements in our understanding of the disease and changes in cost-effectiveness can be addressed by simply adjusting the required score for indication, without the need to modify the entire evaluation scheme.

Physiologically-Based Pharmacokinetic Modeling of Omalizumab to Predict the Pharmacokinetics and Pharmacodynamics in Pediatric Patients

Omalizumab is widely used in clinical practice; however, knowledge gaps in the dosage of omalizumab for children aged 2-6 years with moderate-to-severe persistent allergic asthma have been identified. The aim of this study was to explore dosing regimens for moderately-to-severely allergic pediatric patients aged 2-6 years. The physiologically-based pharmacokinetic (PBPK) model of omalizumab was developed and verified in adult patients, extrapolated to pediatric patients, and simulated for omalizumab by adding two observation chambers (free IgE and total IgE). The simulation results showed that the fold errors of the predicted and observed values of the area under the curve (AUC) and peak plasma concentration (C_max ) were between 0.5 and 2.0, and the average folding error and the absolute average folding error values for all concentration-time data points were 1.09 and 1.48, respectively. The PBPK model combined with pharmacokinetic/pharmacodynamic analysis of omalizumab demonstrated that both the model-derived dose and the original dose could control the average free IgE of 2-6-year-old children with moderate-to-severe allergic asthma below 25 ng/mL, and some of the model-derived doses were lower. This conclusion provides a basis for the selection of dosage in clinical practice reference.

Pharmacokinetics and exposure-efficacy relationships of omalizumab in patients with nasal polyps

The anti-immunoglobulin E (IgE) antibody, omalizumab (Xolair), is approved in the United States for the treatment of allergic asthma and chronic spontaneous urticaria, and has recently been studied for the treatment of nasal polyposis following completion of the two replicate phase 3 studies (POLYP 1 and POLYP 2). The dosing of omalizumab used in the phase 3 studies is based on a combination of patients' pre-treatment IgE level and body weight, similar to the approach used in allergic asthma. The objectives of the current analyses were to evaluate whether the pharmacokinetics (PK) of omalizumab and its pharmacodynamic (PD) effect on free and total IgE level in chronic rhinosinusitis with nasal polyps (CRSwNP) are consistent with those in allergic asthma via population PK/PD modeling and simulation, and to graphically explore exposure-response relationships and free IgE-response relationships in CRSwNP. Omalizumab PK and PD effect of total and free IgE in CRSwNP are generally consistent with those in asthma. Observed post-treatment free IgE suppressions were generally within the target range of the baseline IgE- and body weight-based omalizumab dosing table, with 74.2% and 93.0% of patients achieving a serum free IgE level below 25 ng/mL and 50 ng/mL, respectively at Week 24. Exposure-response analyses indicated that there was no clear correlation between omalizumab or free IgE concentration and key efficacy endpoints within the POLYP studies. Overall, these results indicate that the body weight and IgE-based dosing regimen of omalizumab was appropriate for use in CRSwNP patients.

Guideline for the use of immunobiologicals in chronic rhinosinusitis with nasal polyps (CRSwNP) in Brazil

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The use of immunobiologicals is an option for the management of patients with chronic rinosinusitis with nasal polyps (CRSwNP) refractory to conventional treatment.

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The guideline lists the main drugs currently available in Brazil, their indications, and recommendations for use.

Introduction

Severe uncontrolled chronic rhinosinusitis with nasal polyps has a negative impact on an individual’s quality of life. Therefore, new biologics have emerged for use in specific phenotypes of chronic rhinosinusitis, changing the paradigms of its treatment.

Objective

To review the current status of biologic treatment indications in chronic rhinosinusitis.

Methods

The Brazilian Academy of Rhinology brought together different specialists to suggest a course of action, considering its particularities and aspects related to the national reality.

Results

Of particular interest for decision making will be the identification of subgroups of patients refractory to pre-existing treatment options and the construction of a strategy that improves their quality of life, with the best cost-benefit ratio.

Conclusion

The use of biologics is a valid option for treatment in more severe cases. This strategy must be better understood and improved in the future, with more studies and greater clinical experience.

Pharmacokinetics and pharmacodynamics of monoclonal antibodies for asthma treatment

INTRODUCTION

Asthma is a chronic inflammatory airway disease. It occurs in a 'severe' form in about 8-10% of asthmatic patients. In the last decade, the development of biological drugs (e.g. monoclonal antibodies) allowed to efficiently approach severe asthma. The current therapeutic targets available are mainly those related to TH2 inflammation. Areas covered: The main pharmacokinetic and pharmacodynamic characteristics of the monoclonal antibodies against IL-5, IL-5Ra, IL4-IL13, and IgE, that are currently marketed or understood for severe asthma are discussed in this paper. Expert opinion: The currently available biological drugs represent an excellent therapeutic add-on to traditional drugs, especially in replacing systemic corticosteroid therapies. The different pharmacokinetic and pharmacodynamic characteristics of the drugs, despite sometime sharing the same target, would allow a better personalization of the therapy, tailoring the treatment to the characteristics of the patient.

Establishing in vitro in vivo correlations to screen monoclonal antibodies for physicochemical properties related to favorable human pharmacokinetics

Implementation of in vitro assays that correlate with in vivo human pharmacokinetics (PK) would provide desirable preclinical tools for the early selection of therapeutic monoclonal antibody (mAb) candidates with minimal non-target-related PK risk. Use of these tools minimizes the likelihood that mAbs with unfavorable PK would be advanced into costly preclinical and clinical development. In total, 42 mAbs varying in isotype and soluble versus membrane targets were tested in in vitro and in vivo studies. MAb physicochemical properties were assessed by measuring non-specific interactions (DNA- and insulin-binding ELISA), self-association (affinity-capture self-interaction nanoparticle spectroscopy) and binding to matrix-immobilized human FcRn (surface plasmon resonance and column chromatography). The range of scores obtained from each in vitro assay trended well with in vivo clearance (CL) using both human FcRn transgenic (Tg32) mouse allometrically projected human CL and observed human CL, where mAbs with high in vitro scores resulted in rapid CL in vivo. Establishing a threshold value for mAb CL in human of 0.32 mL/hr/kg enabled refinement of thresholds for each in vitro assay parameter, and using a combinatorial triage approach enabled the successful differentiation of mAbs at high risk for rapid CL (unfavorable PK) from those with low risk (favorable PK), which allowed mAbs requiring further characterization to be identified. Correlating in vitro parameters with in vivo human CL resulted in a set of in vitro tools for use in early testing that would enable selection of mAbs with the greatest likelihood of success in the clinic, allowing costly late-stage failures related to an inadequate exposure profile, toxicity or lack of efficacy to be avoided.

Schistosoma mansoni Tegument (Smteg) Induces IL-10 and Modulates Experimental Airway Inflammation

BACKGROUND

Previous studies have demonstrated that S. mansoni infection and inoculation of the parasite eggs and antigens are able to modulate airways inflammation induced by OVA in mice. This modulation was associated to an enhanced production of interleukin-10 and to an increased number of regulatory T cells. The S. mansoni schistosomulum is the first stage to come into contact with the host immune system and its tegument represents the host-parasite interface. The schistosomula tegument (Smteg) has never been studied in the context of modulation of inflammatory disorders, although immune evasion mechanisms take place in this phase of infection to guarantee the persistence of the parasite in the host.

METHODOLOGY AND PRINCIPAL FINDINGS

The aim of this study was to evaluate the Smteg ability to modulate inflammation in an experimental airway inflammation model induced by OVA and to characterize the immune factors involved in this modulation. To achieve the objective, BALB/c mice were sensitized with ovalbumin (OVA) and then challenged with OVA aerosol after Smteg intraperitoneal inoculation. Protein extravasation and inflammatory cells were assessed in bronchoalveolar lavage and IgE levels were measured in serum. Additionally, lungs were excised for histopathological analyses, cytokine measurement and characterization of the cell populations. Inoculation with Smteg led to a reduction in the protein levels in bronchoalveolar lavage (BAL) and eosinophils in both BAL and lung tissue. In the lung tissue there was a reduction in inflammatory cells and collagen deposition as well as in IL-5, IL-13, IL-25 and CCL11 levels. Additionally, a decrease in specific anti-OVA IgE levels was observed. The reduction observed in these inflammatory parameters was associated with increased levels of IL-10 in lung tissues. Furthermore, Smteg/asthma mice showed high percentage of CD11b+F4/80+IL-10+ and CD11c+CD11b+IL-10+ cells in lungs.

CONCLUSION

Taken together, these findings demonstrate that S. mansoni schistosomula tegument can modulates experimental airway inflammation.

Pharmacokinetics, Pharmacodynamics, and Safety of MEDI4212, an Anti-IgE Monoclonal Antibody, in Subjects with Atopy: A Phase I Study

INTRODUCTION

The anti-IgE therapy omalizumab is currently licensed for the treatment of moderate to severe allergic asthma and chronic idiopathic urticaria. Owing to limitations in the use of omalizumab, a need exists for optimized anti-IgE therapies to broaden clinical indications and patient populations, and to improve dosing schedules. The objective of this phase I, randomized, placebo/omalizumab-controlled, first-in-human, dose-escalation study was to evaluate the pharmacokinetics, pharmacodynamics, and safety of the high-affinity, anti-IgE therapy MEDI4212 in non-Japanese and Japanese subjects with atopy and/or diagnostic IgE ≥ 30 IU/mL.

METHODS

Subjects with atopy and/or baseline IgE ≥ 30 IU/mL were randomized to a single dose of subcutaneous (5, 15, 60, 150, or 300 mg) or intravenous (300 mg) MEDI4212, subcutaneous omalizumab, or placebo. Following administration, pharmacokinetic, pharmacodynamic [IgE (free and total), and cellular FcεRI expression], and safety assessments were made.

RESULTS

MEDI4212 rapidly suppressed free serum IgE to a greater extent than omalizumab; however, recovery of free IgE to baseline in MEDI4212-dosed subjects was rapid when compared with the slow and gradual recovery seen in omalizumab-dosed individuals. The loss of IgE suppression corresponded with a rapid decrease of serum MEDI4212. FcεRI expression on dendritic cells and basophils was reduced following MEDI4212 dosing. MEDI4212 was well tolerated by subjects; adverse events were generally of low severity and no subjects discontinued due to adverse events.

CONCLUSIONS

The increased potency of MEDI4212 may be of clinical interest for individuals with high-diagnostic IgE levels where more extensive IgE suppression is required for clinical response. However, the modest duration of free IgE suppression below the target concentration noted with MEDI4212 in this study suggests limited potential for dosing schedule advantages over omalizumab.

FUNDING

MedImmune.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT01544348.

Immunotherapy in allergy and cellular tests: state of art

The basophil activation test (BAT) is an in vitro assay where the activation of basophils upon exposure to various IgE-challenging molecules is measured by flow cytometry. It is a cellular test able to investigate basophil behavior during allergy and allergy immunotherapy. A panoply of critical issues and suggestive advances have rendered this assay a promising yet puzzling tool to endeavor a full comprehension of innate immunity of allergy desensitization and manage allergen or monoclonal anti-IgE therapy. In this review a brief state of art of BAT in immunotherapy is described focusing onto the analytical issue pertaining BAT performance in allergy specific therapy.

Pharmacokinetics, pharmacodynamics and physiologically-based pharmacokinetic modelling of monoclonal antibodies

Development of monoclonal antibodies (mAbs) and their functional derivatives represents a growing segment of the development pipeline in the pharmaceutical industry. More than 25 mAbs and derivatives have been approved for a variety of therapeutic applications. In addition, around 500 mAbs and derivatives are currently in different stages of development. mAbs are considered to be large molecule therapeutics (in general, they are 2-3 orders of magnitude larger than small chemical molecule therapeutics), but they are not just big chemicals. These compounds demonstrate much more complex pharmacokinetic and pharmacodynamic behaviour than small molecules. Because of their large size and relatively poor membrane permeability and instability in the conditions of the gastrointestinal tract, parenteral administration is the most usual route of administration. The rate and extent of mAb distribution is very slow and depends on extravasation in tissue, distribution within the particular tissue, and degradation. Elimination primarily happens via catabolism to peptides and amino acids. Although not definitive, work has been published to define the human tissues mainly involved in the elimination of mAbs, and it seems that many cells throughout the body are involved. mAbs can be targeted against many soluble or membrane-bound targets, thus these compounds may act by a variety of mechanisms to achieve their pharmacological effect. mAbs targeting soluble antigen generally exhibit linear elimination, whereas those targeting membrane-bound antigen often exhibit non-linear elimination, mainly due to target-mediated drug disposition (TMDD). The high-affinity interaction of mAbs and their derivatives with the pharmacological target can often result in non-linear pharmacokinetics. Because of species differences (particularly due to differences in target affinity and abundance) in the pharmacokinetics and pharmacodynamics of mAbs, pharmacokinetic/pharmacodynamic modelling of mAbs has been used routinely to expedite the development of mAbs and their derivatives and has been utilized to help in the selection of appropriate dose regimens. Although modelling approaches have helped to explain variability in both pharmacokinetic and pharmacodynamic properties of these drugs, there is a clear need for more complex models to improve understanding of pharmacokinetic processes and pharmacodynamic interactions of mAbs with the immune system. There are different approaches applied to physiologically based pharmacokinetic (PBPK) modelling of mAbs and important differences between the models developed. Some key additional features that need to be accounted for in PBPK models of mAbs are neonatal Fc receptor (FcRn; an important salvage mechanism for antibodies) binding, TMDD and lymph flow. Several models have been described incorporating some or all of these features and the use of PBPK models are expected to expand over the next few years.

Therapeutic options for severe asthma

As the overall prevalence of asthma has escalated in the past decades, so has the population of patients with severe asthma. This condition is often difficult to manage due to the relative limitation of effective therapeutic options for the physician and the social and economic burden of the disease on the patient. Management should include an evaluation and elimination of modifiable risk factors such as smoking, allergen exposure, obesity and non-adherence, as well as therapy for co-morbidities like gastro-esophageal reflux disease and obstructive sleep apnea. Current treatment options include conventional agents such as inhalational corticosteroids, long acting β(2) agonists, leukotriene antagonists, and oral corticosteroids. Less conventional treatment options include immunotherapy with methotrexate, cyclosporine and tacrolimus, biological drugs like monoclonal antibodies, tumor necrosis factor-α blockers and oligonucleotides, phosphodiesterase inhibitors, antimicrobials and bronchial thermoplasty.

Omalizumab: a review of its use in the treatment of allergic asthma

Omalizumab, a monoclonal antibody that targets circulating IgE, is approved as add-on therapy for adult and adolescent patients with severe allergic asthma in the EU and moderate to severe allergic asthma in the US. Several randomized, double-blind trials have demonstrated the therapeutic efficacy of subcutaneously administered omalizumab as add-on therapy in patients with allergic asthma. The INNOVATE study included only patients with severe persistent disease, and omalizumab was associated with a statistically significant relative reduction of 26% in the rate of clinically significant asthma exacerbations (primary endpoint) compared with placebo (after adjustment for an imbalance in the exacerbation history at baseline). Results for a number of secondary outcomes also significantly favored omalizumab over placebo. Two large studies in patients with moderate to severe allergic asthma showed that, compared with placebo, omalizumab was associated with statistically significant relative reductions of 41-58% in the mean number of asthma exacerbations (primary endpoint) during the trial. Omalizumab also significantly reduced asthma symptom scores and the use of inhaled corticosteroids and rescue medication. Moreover, all of these trials showed that omalizumab was associated with clinically and statistically significant improvements from baseline in overall asthma-related quality of life. In general, omalizumab was well tolerated in clinical trials. Most adverse events were mild or moderate in severity and occurred at a similar frequency among omalizumab and placebo recipients. Injection-site reactions were the most commonly reported adverse events in clinical trials with omalizumab. Although rare, anaphylactic reactions have occurred following administration of omalizumab, and appropriate precautions should be taken. Results of several large randomized trials, therefore, have established omalizumab as an effective and well tolerated agent for use as add-on therapy in patients with severe persistent allergic asthma (EU labeling) or those with moderate to severe disease (US labeling). In addition, international treatment guidelines acknowledge the importance of omalizumab as a treatment option in these difficult-to-treat patient populations.

Predictivity of animal studies for human injection site reactions with parenteral drug products

The value and predictive power of nonclinical studies for potential effects of investigational medicinal products in humans is often debated. The subject of general predictivity of animal toxicity studies has been addressed on several occasions, with one of the most recent efforts being conducted by an ILSI Task Group [Olson H, et al. Concordance of the toxicity of pharmaceuticals in humans and animals. Regul Toxicol Pharmacol 2000; 32: 56-67]. This review provides a summary of the evaluation of cutaneous toxicity, its histopathological assessment, and experience of the biopharmaceutical industry with respect to injection site reactions with parenteral drug products with a pragmatic perspective on the predictivity of standard animal studies with respect to these responses in humans.

Impact of omalizumab on quality-of-life outcomes in patients with moderate-to-severe allergic asthma

BACKGROUND

Moderate-to-severe allergic asthma has a substantial impact on patients' quality of life (QOL). Despite care consistent with treatment guidelines, many patients with moderate-to-severe asthma still experience variability in asthma control, signaling an unmet need within this population. Omalizumab has recently demonstrated clinical efficacy and safety in treating IgE-mediated asthma.

OBJECTIVE

To summarize asthma-related QOL outcomes associated with omalizumab therapy in moderate-to-severe allergic asthma.

METHODS

A systematic review and meta-analysis of asthma-related QOL on data from published clinical trials and unpublished clinical study reports were conducted on omalizumab. The Juniper Asthma Quality of Life Questionnaire (AQLQ) measured asthma-related QOL.

RESULTS

Statistically significant results for asthma-related QOL end points consistently favored omalizumab over placebo. Moderate to large effect sizes in the omalizumab groups were observed across the clinical trials and during study extension phases. A meta-analysis indicated a 1.6- to 2-fold increase in moderate (> or = 1 point) and a 1.8- to 2.1-fold increase in large (> or = 1.5 point) improvements in AQLQ overall scores in the omalizumab-treated group compared with placebo during the steroid-stabilization and steroid-reduction phases of the trials.

CONCLUSIONS

Significant differences and large effect sizes favoring omalizumab were observed despite the control group receiving active, guideline-consistent treatment. The meta-analysis findings demonstrate that omalizumab treatment provides QOL benefits in patients with moderate-to-severe allergic asthma.

Pharmacokinetics and concentration–effect relationships of therapeutic monoclonal antibodies and fusion proteins

Although monoclonal antibodies (mAbs) constitute a major advance in therapeutics, their pharmacokinetic (PK) and pharmacodynamic (PD) properties are not fully understood. Saturable mechanisms are thought to occur in distribution and elimination of mAbs, which are protected from degradation by the Brambell's receptor (FcRn). The binding of mAbs to their target antigen explains part of their nonlinear PK and PD properties. The interindividual variability in mAb PK can be explained by several factors, including immune response against the biodrug and differences in the number of antigenic sites. The concentration-effect relationships of mAbs are complex and dependent on their mechanism of action. Interindividual differences in mAb PD can be explained by factors such as genetics and clinical status. PK and concentration-effect studies are necessary to design optimal dosing regimens. Because of their above-mentioned characteristics, the interindividual variability in their dose-response relationships must be studied by PK-PD modelling.