Severe Asthma and Biological Therapy: When, Which, and for Whom

Younger severe asthma patients with interleukin 4 (CC variant) and dupilumab treatment are more likely to achieve clinical remission

BACKGROUND AND OBJECTIVES

Asthma is a complex condition characterized by variable respiratory symptoms and chronic inflammation. In recent years, the use of biologics in severe asthma patients led to significant improvements in symptom control and disease outcomes. This has prompted healthcare providers to explore the possibility of achieving clinical remission (CR). This study aimed to evaluate the prevalence of clinical remission in severe asthma patients treated with biologics. Additionally, to identify factors associated with achieving clinical remission.

METHODS

The study recruited 116 patients from a national severe asthma registry in Kuwait, focusing on patients who had been treated with biologic therapy for at least 12 months. CR was defined as the absence of exacerbations and oral corticosteroids (OCS) use, an Asthma Control Test (ACT) score of ≥ 20, Asthma Control Questionnaire (ACQ-6) score of ≤ 0.75 and forced expiratory volume in one second (FEV1) ≥ 80% predicted. Data were collected on demographics, clinical, and functional parameters; including biomarkers such as blood eosinophils count (BEC), total immunoglobulin E (IgE), and fractional exhaled nitric oxide (FeNO), as well as the polymorphism patterns of the interleukin-4 (IL-4) and tumor necrosis factor-alpha (TNF-α) genes.

RESULTS

Patients with severe asthma were predominantly female (68.9%) with an average age of 54.09 years. Most had adult-onset asthma (67.3%), comorbid allergic rhinitis (AR) (81.03%), and experienced frequent exacerbations, with a median of four corticosteroids-requiring flare-ups per year. The allergic eosinophilic phenotype was common (74.14%), and a significant portion carried the CC genotype of the IL-4 gene (51.72%) or the GG genotype of the TNFα gene (57.76%). Biologic therapy significantly improved asthma control, reduced exacerbations and OCS use while improved lung function (p = 0.001 for all). About 18.1% of patients achieved CR after at least 12 months of biologic therapy, with dupilumab being the most effective, especially in biologic-naive patients. A multiple logistic regression analysis found that increasing age was negatively associated with CR (OR 0.95, p = 0.02), while the CC genotype of the IL-4 gene (OR 4.57, p = 0.008) and the use of dupilumab (OR 3.63, p = 0.001) were strong positive predictors of CR.

CONCLUSION

This study suggested that CR can be achieved in patients with severe asthma. However, biologic therapy, particularly dupilumab, offers a promising avenue for achieving CR in comparison to other biologics, especially in younger patients with specific genetic profiles (CC genotype of the IL-4 gene).

Real-World Biologic Use Patterns in Severe Asthma, 2015-2021: The CLEAR Study

Background

Biologics targeting immunoglobulin E, interleukin (IL)-4/IL-13 or IL-5 signaling are effective at treating severe asthma; however, individual patients' responses may be suboptimal, leading to therapy switching or stopping. The CLEAR study aimed to assess real-world biologic use patterns and associated clinical outcomes in patients receiving care for severe asthma.

Methods

CLEAR was a multicenter, observational study that included adults (≥18 years old) from 23 countries enrolled in the International Severe Asthma Registry between December 2015 and August 2021. Patients who initiated biologic therapy were categorized as continuing the initial biologic for 6 months, switching to another biologic within 6 months or stopping biologic treatment within 6 months. Outcomes were assessed using the closest available data to 12 months after biologic initiation, using propensity score-weighted multivariable regression models.

Results

Among 1,859 patients who initiated biologic therapy, 1,116 (60.0%) continued, 474 (25.5%) switched and 269 (14.5%) stopped treatment. Patients who switched or stopped therapy had a higher annualized asthma exacerbation rate post-initiation than those who continued (adjusted incidence rate ratio [aIRR] [95% confidence interval]: switched, 1.83 [1.51, 2.22]; stopped, 1.53 [1.19, 1.95]) and were more likely to have uncontrolled asthma at last assessment (adjusted odds ratio: switched, 5.40 [3.12, 9.33]; stopped, 4.02 [2.32, 6.98]). Compared with those who continued therapy, patients who switched had a higher long-term daily oral corticosteroid dose (adjusted β: 3.77 [1.71, 4.37] mg) and higher rates of hospitalizations (aIRR: 2.58 [1.52, 4.37]) and emergency room visits (aIRR: 2.12 [1.39, 3.24]).

Conclusion

Switching or stopping biologic therapy was associated with worse clinical outcomes than continuing the initial therapy.

Effectiveness of biological therapy in severe asthma: a retrospective real-world study

Aim- To compare the effectiveness of different biologic medications for the treatment of severe asthma.

METHODS

We retrospectively collected data on 74 patients treated with one of four different biologics (omalizumab, mepolizumab, reslizumab, or benralizumab) at the Jordanovac Clinic for Pulmonary Diseases, Zagreb, Croatia for at least two years. The patients were compared in terms of the number of exacerbations, dose of oral corticosteroids (OCS), asthma control test (ACT), forced expiratory volume in 1 second (FEV1), forced vital capacity, fraction of exhaled nitric oxide (FeNO), number of blood eosinophils, and total immunoglobulin E (IgE).

RESULTS

All treatment outcome measures, except FeNO, significantly improved in the two-year period (P<0.001). The number of acute exacerbations decreased in all groups. Reslizumab-treated patients showed the greatest improvement in ACT score, and the omalizumab-treated patients experienced the least (P=0.018). The benralizumab group showed the greatest reduction in eosinophil number, and the omalizumab group the lowest (P<0.001). The mepolizumab group showed the greatest improvement in FEV1.

CONCLUSION

Both anti-IgE and anti-IL-5 treatments effectively reduced exacerbation rates, OCS daily needs, and symptom burden. Multiple predictive biomarkers are needed for the best individual monitoring.

Eosinophil count testing in patients with asthma varies by healthcare provider type in the US: a retrospective study

BACKGROUND

Patients with asthma with an eosinophilic phenotype may be eligible for additional treatment options to improve disease control; however, the prevalence and frequency of eosinophil testing is unknown. This study assessed blood eosinophil count testing prevalence in patients with asthma by exacerbation frequency and healthcare provider (HCP) type.

METHODS

This was a retrospective, longitudinal, real-world study (GSK ID: 214470) utilizing the Merative Explorys® Universe electronic health records database. Eligible patients had ≥ 2 asthma diagnostic codes (January 2016-December 2018) (Index date: first asthma diagnosis). Outcomes included patient demographics and clinical characteristics (12 months pre-index [baseline]), and prevalence of blood eosinophil count testing, stratified by exacerbation frequency (infrequent exacerbations [< 2]) or frequent exacerbations [≥ 2] or primary HCP (Allergist/Pulmonologist, a primary care physician [PCP] or other HCP) during the 12 months post-index (follow-up).

RESULTS

Of 400,254 patients included (mean age: 51.2 years; 70.8% female), the most common provider type at baseline was a PCP (76.8%). A higher proportion of patients with frequent exacerbations had blood eosinophil count tests at baseline (55.4-69.5%) and follow-up (67.9-75.1%), compared with patients with infrequent exacerbations (55.5-63.7%, 62.4-67.3%). Significantly more patients in the Allergist/Pulmonologist subgroup had ≥ 1 blood eosinophil count test result compared with patients in the PCP subgroup at both baseline (59.9% vs. 50.7%; p < 0.001) and follow-up (59.0% vs. 56.2%; p < 0.001). In the total population, the mean (SD) number of tests ordered was 3.4 (5.3) and 4.1 (6.4) during the baseline and follow-up periods, respectively. A greater mean number of tests were ordered for patients with frequent exacerbations, most apparently in the Allergist/Pulmonologist subgroup during baseline and follow-up (7.4 vs. 4.9). For patients with frequent exacerbations and blood eosinophil count test results, the mean (SD) number of tests ranged from 3.1 (4.6) to 5.8 (8.3) at baseline and 5.1 (8.5) to 7.4 (10.6) during follow-up.

CONCLUSIONS

The prevalence of blood eosinophil count testing in patients with asthma remains suboptimal. Routine blood eosinophil count testing should be considered by HCPs for patients with asthma to increase identification of the eosinophilic asthma phenotype, which may inform the decision to advance to targeted biologic therapy.

Expert opinion on diagnosis and management of Severe Asthma in low and middle income countries (LMIC) with focus on India

OBJECTIVE

In this document, 9 Indian experts have evaluated the factors specific to LMICs when it came to Severe Asthma (SA) diagnosis, evaluation, biologic selection, non-biologic treatment options, and follow-up.

DATA SOURCES

A search was performed using 50 keywords, focusing on the Indian/LMICs perspective, in PubMed, Cochrane Library, and Google Scholar. The key areas of the search were focused on diagnosis, phenoendotyping, non-biological therapies, selecting a biologic, assessment of treatment response, and management of exacerbation.

STUDY SELECTIONS

The initial search revealed 1826 articles, from these case reports, observational studies, cohort studies, non-English language papers, etc., were excluded and we short-listed 20 articles for each area. Five relevant articles were selected by the experts for review.

RESULTS

In LMICs, SA patients may be referred to the specialist for evaluation a little late for Phenoendotyping of SA. While biologic therapy is now a standard of care, pulmonologists in LMICs may not have access to all the investigations to phenoendotype SA patients like fractional exhaled nitric oxide (FeNO), skin prick test (SPT), etc., but phenotyping of SA patients can also be done with simple blood investigations, eosinophil count and serum immunoglobulin E (IgE). Choosing a biologic in the overlapping phenotype of SA and ACO patients is also a challenge in the LMICs.

CONCLUSIONS

Given the limitations of LMIC, it is important to select the right patient and explain the potential benefits of biological therapy. Non-biologic add-on therapies can be attempted in a resource-limited setting where biological therapy is not available/feasible for patients.

Clinical remission and control in severe asthma: agreements and disagreements

Over the last two decades, we have witnessed great advancements in our understanding of the immunological pathways of asthma, leading to the development of targeted therapies, such as biologic drugs, that have radically and definitively changed the clinical outcomes of severe asthma. Despite the numerous therapeutic options available, ~4-10% of all people with asthma have severe or uncontrolled asthma, associated with an increased risk of developing chronic oral corticosteroid use, fixed airflow limitation, exacerbations, hospitalization and, finally, increased healthcare costs. The new concept of disease modification in asthma comes from the evolution of asthma management, which encompasses phenotyping patients with different inflammatory endotypes characterizing the disease, followed by the advent of more effective therapies capable of targeting the proximal factors of airway inflammation. This treat-to-target approach aims to achieve remission of the disease. Because the novel treatment paradigm for severe asthma with the advent of biologic therapies is no longer clinical control but rather clinical remission - a step closer to the concept of cure - a deeper and more accurate understanding of the critical causal mechanisms and endotypes of asthma is necessary to achieve the goal of clinical remission, which has the potential to generate real life-changing benefits for patients. This review aims to frame the evolution of the debated concept of clinical remission and provide clinicians with insights that may be helpful in achieving remission in the greatest number of patients.

Real-World Safety Profile of Biologic Drugs for Severe Uncontrolled Asthma: A Descriptive Analysis from the Spanish Pharmacovigilance Database

Background: The present investigation provides a thorough analysis of adverse drug reactions (ADRs) reported in the Database of the Spanish Pharmacovigilance System (FEDRA) for biologic medications primarily indicated for severe refractory asthma, including omalizumab, mepolizumab, reslizumab, benralizumab, dupilumab, and tezepelumab. Our main objective was to identify ADRs not documented in the drugs' Technical Sheets (summary of product characteristics, SmPC), potentially indicating unrecognized risks meriting pharmacovigilance attention. Methods: Data spanning from each drug's market introduction until 22 January 2024, were analyzed, sourced from direct submissions to the Spanish Pharmacovigilance System, industry communications, and literature reviews. We evaluated notifications impartially to ensure a comprehensive review of all the ADRs associated with these medications. Results: This investigation underlines the critical role of post-marketing surveillance in enhancing patient safety. It emphasizes the necessity for healthcare professionals to report ADRs comprehensively to foster a robust pharmacovigilance system. Furthermore, the study highlights gaps between the reported ADRs and the information provided in SmPCs, signaling potential areas for improvement in drug safety monitoring and regulatory oversight. Conclusions: Finally, these findings may contribute to informed decision making in clinical practice and regulatory policy, ultimately advancing patient care and safety in the management of severe uncontrolled asthma.

Evaluation of gender differences in the pharmacokinetics of oral zileuton nanocrystalline formulation using a rat model

Zileuton is a leukotriene inhibitor used to treat asthma. As a BCS class II drug it exhibits challenges with solubility which likely impact its absorption. As patient gender significantly impacts the pharmacokinetics of many drugs, this study aimed to investigate potential gender-based pharmacokinetic differences after oral zileuton administration in rats. Male and female Sprague Dawley rats received single oral gavage doses of pure zileuton as an active pharmaceutical ingredient (30 mg/kg body weight (bw)), physical mixture (PM; at 30 mg/kg bw of the formulation contains zileuton, kollidon VA64 fine, dowfax2A1 and trehalose), and nanocrystalline formulation of zileuton (NfZ; at 30 mg/kg bw of the formulation). Plasma, tissue, and urine concentrations were quantified using high performance liquid chromatography (HPLC). Noncompartmental pharmacokinetic analysis showed higher zileuton levels in the plasma of female versus male rats across all evaluated forms of zileuton (API, PM, and NfZ). Female rats demonstrated higher peak plasma concentrations (Cmax) and increased area under the plasma concentration-time curve (AUC) relative to males, regardless of formulation. These findings reveal substantial gender disparities in the pharmacokinetics of zileuton in the rat model. This study emphasizes the critical need to evaluate gender differences during preclinical drug development to enable gender-based precision dosing strategies for equivalent efficacy/safety outcomes in male and female patients. Additional studies are warranted to investigate underlying mechanisms of such pharmacokinetic gender divergences.

The pharmacological management of asthma in adults: 2023 update

INTRODUCTION

The pharmacotherapy of asthma is a dynamic process that changes as our knowledge of the underlying pathophysiology and treatment of this disease continues to evolve. This implies the need for continuous revision of the recommendations of asthma guidelines and strategies.

AREAS COVERED

This review summarizes the latest key practical information on the pharmacological management of asthma in adults. We provide the background to the 2023 update of the GINA strategy report, focusing on changes and discussing areas of uncertainty. We review current and emerging pharmacotherapy for uncontrolled asthma, including synthetic agents and new biologics, and provide expert perspectives and opinions on the treatment of uncontrolled asthma.

EXPERT OPINION

The current pharmacological treatment of asthma, based on a step-by-step, control-based approach, with ICSs, LABAs and LAMAs being the mainstay generally provides good symptom control. Biologic therapies are often effective in treating T2high severe asthma. However, there is still room for improvement, such as the discovery of new molecules that specifically target chronic inflammation and, most importantly, the ability to provide solutions to the various areas of uncertainty that still exist. Also finding solutions to improve the accessibility and affordability of rescue ICS in resource-constrained settings is critical.

Predictors of Early and Late Lung Function Improvement in Severe Eosinophilic Asthma on Type2-Biologics in the PRISM Study

BACKGROUND

The determinants linked to the short- and long-term improvement in lung function in patients with severe eosinophilic asthma (SEA) on biological treatment (BioT) remain elusive.

OBJECTIVE

We sought to identify the predictors of early and late lung function improvement in patients with SEA after BioT.

METHODS

140 adult patients with SEA who received mepolizumab, dupilumab, or reslizumab were followed up for 6 months to evaluate improvement in forced expiratory volume in one second (FEV1). Logistic regression was used to determine the association between potential prognostic factors and improved lung function at 1 and 6 months of treatment.

RESULTS

More than a third of patients with SEA using BioT showed early and sustained improvements in FEV1 after 1 month. A significant association was found between low baseline FEV1 and high blood eosinophil count and sustained FEV1 improvement after 1 month (0.54 [0.37-0.79] and 1.88 [1.28-2.97] odds ratios and 95% confidence interval, respectively). Meanwhile, among patients who did not experience FEV1 improvement after 1 month, 39% exhibited improvement at 6 months follow-up. A high ACT score measured at this visit was the most reliable predictor of late response after 6 months of treatment (OR and 95% CI 1.75 [1.09-2.98]).

CONCLUSION

Factors predicting the efficacy of biological agents that improve lung function in SEA vary according to the stage of response.

Clinical Remission in Patients Affected by Severe Eosinophilic Asthma on Dupilumab Therapy: A Long-Term Real-Life Study

Background. Nowadays, highly selective biological drugs offer the possibility of treating severe type 2 asthma. However, in the real-life setting, it is crucial to confirm the validity of the chosen biological treatment by evaluating the achievement of clinical remission. Study purpose. The main aims of this real-life study were to evaluate the efficacy of dupilumab in terms of clinical, functional, and inflammatory outcomes at 6, 12, 18, and 24 months of treatment and to estimate the percentage of patients achieving partial or complete clinical remission at 12 and 24 months of treatment. In addition, we attempted to identify whether baseline clinical characteristics of patients could be associated with clinical remission at 24 months of treatment. Materials and methods. In this observational prospective study, 20 outpatients with severe uncontrolled eosinophilic asthma were prescribed dupilumab and followed-up after 6, 12, 18, and 24 months of treatment. At each patient visit, the need for oral corticosteroids (OCS) and corticosteroid required dose, number of exacerbations during the previous year or from the previous visit, asthma control test (ACT) score, pre-bronchodilator forced expiratory volume in the 1st second (FEV1), fractional exhaled nitric oxide at a flow rate of 50 mL/s (FeNO50), and blood eosinophil count were assessed. Results. The number of OCS-dependent patients was reduced from 10 (50%) at baseline to 5 (25%) at one year (T12) and 2 years (T24). The average dose of OCS required by patients demonstrated a significant reduction at T12 (12.5 ± 13.75 mg vs. 2.63 ± 3.94 mg, p = 0.015), remaining significant even at T24 (12.5 ± 13.75 mg vs. 2.63 ± 3.94 mg, p = 0.016). The number of exacerbators showed a statistically significant decrease at T24 (10 patients, 50% vs. 3 patients, 15%, p = 0.03). The mean number of exacerbations demonstrated a statistically significant reduction at T24 (1.45 ± 1.58 vs. 0.25 ± 0.43, p = 0.02). The ACT score improved in a statistically significant manner at T12 (15.30 ± 4.16 vs. 21.40 ± 2.35, p < 0.0001), improving further at T24 (15.30 ± 4.16 vs. 22.10 ± 2.59, p < 0.0001). The improvement in pre-bronchodilator FEV1 values reached statistical significance at T24 (79.5 ± 14.4 vs. 87.7 ± 13.8, p = 0.03). The reduction in flow at the level of the small airways (FEF25-75%) also demonstrated an improvement, although it did not reach statistical significance either at T12 or T24. A total of 11 patients (55%) showed clinical remission at T12 (6 complete + 5 partial) and 12 patients (60%) reached clinical remission at T24 (9 complete + 3 partial). Only obesity was associated with a negative odds ratio (OR) for achieving clinical remission at T24 (OR: 0.03, 95% CI: 0.002-0.41, p = 0.004). No other statistically significant differences in baseline characteristics emerged between patients who reached clinical remission at T24 and the group of patients who did not achieve this outcome. Conclusion. Dupilumab appears to be an effective drug in promoting achievement of clinical remission in patients with severe uncontrolled eosinophilic asthma. The achievement of clinical remission should be continuously evaluated during treatment. Further studies are needed to clarify whether certain baseline clinical characteristics can help predict dupilumab favorable outcomes.

Investigational thymic stromal lymphopoietin inhibitors for the treatment of asthma: a systematic review

INTRODUCTION

Severe asthma patients often remain uncontrolled despite high-intensity therapies. Biological therapies targeting thymic stromal lymphopoietin (TSLP), a key player in asthma pathogenesis, have emerged as potential options. Currently, the only TSLP inhibitor approved for the treatment of severe asthma is the immunoglobulin G (IgG) 2λ anti-TSLP monoclonal antibody (mAb) tezepelumab.

AREAS COVERED

This systematic review assesses the efficacy and safety of investigational TSLP inhibitors across different stages of development for asthma treatment.

EXPERT OPINION

TSLP contributes to airway inflammation, making it a pivotal therapeutic target. Ecleralimab, an inhaled antibody fragment antigen binding, shows promising evidence in enhancing efficacy and reducing systemic adverse events. SAR443765, with its NANOBODY® formulation and bispecific inhibition of TSLP and IL-13, offers improved tissue penetration and efficacy. The mAB TQC2731 exhibits high in vitro bioactivity, and the strength of the mAb UPB-101 is to act against the TSLP receptor. Some studies include mild and moderate asthma patients, suggesting the potential for extending biological therapy to non-severe patients. This systematic review highlights the potential of TSLP inhibitors as valuable additions to asthma treatment, even in milder forms of the disease. Future research and cost-reduction efforts are needed to expanding access to these promising therapies.

Cost-effectiveness and resource use analysis of patients with asthma before and after treatment with mepolizumab in a real-life setting

OBJECTIVE

To define the cost-effectiveness and health resource use of mepolizumab in a cohort of patients with severe eosinophilic asthma in real-life conditions in Spain.

METHODS

This was an observational, retrospective, single-center study. Patients included were diagnosed with severe eosinophilic asthma and treated with mepolizumab 100 mg subcutaneous (SC) 4-weekly for 12 months. Outcomes evaluated: incremental cost-effectiveness ratio (ICER), number of exacerbations, disease control with the Asthma Control Test (ACT), Asthma Quality of Life Questionnaire (AQLQ), and direct and indirect cost per patient.

RESULTS

12 months after mepolizumab initiation, a significant decrease in exacerbations was shown, from a mean (standard deviation [SD]) of 3.1 (2.6) to 0.7 (1.5), an increase from 4.9 (0.4) to 6.1 (0.5) in AQLQ, and from 14.9 (5.7) to 21.5 (3.9) in ACT scores. The number of cortico-dependent patients significantly decreased from 53.3% to 13.3% during this period. There was a significant decrease of 94% in the cost of hospitalization, from a mean (SD) of €4063.9 (5423.9) pretreatment to €238.6 (1306.9) post-treatment (p = 0.0003). Total costs decreased significantly from a median of €2,423.1 (1,512.8; 9,320.9) pretreatment to €1,177.5 (965.0; 1,737.8) post-treatment if mepolizumab was excluded. ICER per exacerbation avoided was €3606.9, per 3-point ACT score increase €3934.8, and per 0.5-point AQLQ score increase €3606.9.

CONCLUSIONS

Mepolizumab improves control of asthma and quality of life in patients with severe diseases in a cost-effectiveness range. The number of exacerbations decreased, and there was a clear reduction in primary care visits and hospitalizations. Further economic analyses of biological therapies for asthma are required.

Factors influencing poor response to type 2 targeted therapies in severe asthma: a retrospective cohort study

BACKGROUND

A significant breakthrough has been made in treating severe asthma, with the recognition of various asthma phenotypes and an updated management guideline. Type 2 targeted therapies, such as benralizumab and omalizumab; have been identified as an effective treatment for severe asthma, improving patient response, lung function tests and asthma symptom control. This study aimed to evaluate factors contributing to poor response to therapy.

METHODS

A retrospective single-center cohort study of 162 patients with severe asthma who started biologic therapy; their data were retrieved from medical records for further analysis. Poor responders were patients remained clinically and functionally uncontrolled despite even after augmenting all treatment options.

RESULTS

Childhood-onset asthma, bronchiectasis, poor symptom control (ACT below 19), severe airway obstruction (< 60% predicted), and maintenance oral corticosteroid (mOCS) use were significantly associated with poor response to omalizumab and benralizumab; p = 0.0.4 and 0.01; 0.003 and 0.01; 0.01 and 0.001, 0.05 and 0.04; 0.006 and 0.02, respectively. However, chronic rhinosinusitis and IgE < 220kIU/L were associated with higher poor response rates to omalizumab (p = 0.01 and 0.04, respectively). At the same time, female patients and those with blood eosinophils level < 500 cells/mm3 had a higher poor response rate to benralizumab (p = 0.02 and 0.01, respectively). Ischemic heart disease (IHD), bronchiectasis, and continued use of OCS increased the likelihood of poor response to omalizumab by 21, 7, and 24 times (p = 0.004, 0.008, and 0.004, respectively). In contrast, the female gender, childhood-onset asthma and higher BMI increased the likelihood of poor response to benralizumab by 7, 7 and 2 times more, p = 0.03, 0.02 and 0.05, respectively.

CONCLUSION

Poor response to omalizumab treatment was independently associated with ischemic heart disease (IHD), bronchiectasis, and a history of maintenance oral corticosteroid (mOCS) use. Conversely, poor response to benralizumab therapy was independently linked to female gender, childhood-onset asthma and higher body mass index (BMI).

Unanswered questions on the use of biologics in pediatric asthma

The emergence of biologic therapies for the management of asthma has been a revolutionary change in our capacity to manage this disease. Since the launch of omalizumab, several other biologics have been marketed or are close to being marketed, suggesting that a plethora of monoclonal antibodies can be expected in the coming years. This will facilitate the transition to the paradigm of personalized medicine, but on the other hand will decisively further complicate the choice of the most appropriate treatment, in the absence of reliable enough biological markers. For these reasons, along with the relatively short time of use with these treatments, there are recurrently arising questions for which there are not even moderately documented answers, and for which the only solution must be based, with all reservations, on the combination of indirect evidence and expertise. In this paper, we attempt to address such questions, providing relevant commentaries and considering the whole width of the evidence base.

Real-world impact of dupilumab on asthma disease burden in Japan: The CROSSROAD study

BACKGROUND

Dupilumab, a human monoclonal anti-interleukin (IL)-4Ra antibody blocks the shared receptor component of IL-4 and IL-13, drivers of type 2 inflammation. Dupilumab is approved for severe/refractory asthma inadequately controlled by existing therapies, but knowledge of its effect on real-world disease burden is lacking. This study investigates real-world effects of dupilumab on asthma exacerbation risk and oral corticosteroid (OCS) use in Japanese individuals with asthma.

METHODS

This retrospective, cohort study used a Japanese insurance claims database to identify patients who started dupilumab between 26 March 2019-31 May 2020. Patients were followed for ±365 days from dupilumab initiation. The study primarily assessed the annual incidence rate of severe asthma exacerbations occurring simultaneously with hospitalizations or OCS bursts. Secondary and exploratory endpoints assessed OCS dosage and duration, and healthcare resource utilization (HRU), respectively.

RESULTS

At dupilumab initiation (N = 215), mean age was 57.2 years, 41.9% of patients were aged ≥65 years, and 59.5% were female. Dupilumab significantly reduced the annual incidence of severe asthma exacerbations from 1.29 to 0.74 (95% confidence interval, 0.44-0.76) per patient per year. Mean OCS dosage decreased from 10.4 to 7.2 mg/day in chronic OCS users; median frequency of OCS bursts decreased from 3 to 0. Both unscheduled outpatient visits (35.8% vs 29.8%) and hospitalizations (21.9% vs 12.1%) decreased. Mean (standard deviation) duration of hospitalization also decreased from 6.7 (27.6) to 2.2 (8.1) days.

CONCLUSIONS

Japanese patients with asthma who received dupilumab had reduced incidence rates of severe asthma exacerbations, OCS use, and HRU over 12 months.

Revisiting asthma pharmacotherapy: where do we stand and where do we want to go?

Several current guidelines/strategies outline a treatment approach to asthma, which primarily consider the goals of improving lung function and quality of life and reducing symptoms and exacerbations. They suggest a strategy of stepping up or down treatment, depending on the patient's overall current asthma symptom control and future risk of exacerbation. While this stepwise approach is undeniably practical for daily practice, it does not always address the underlying mechanisms of this heterogeneous disease. In the last decade, there have been attempts to improve the treatment of severe asthma, such as the addition of a long-acting antimuscarinic agent to the traditional inhaled corticosteroid/long-acting β2-agonist treatment and the introduction of therapies targeting key cytokines. However, despite such strategies several unmet needs in this population remain, motivating research to identify novel targets and develop improved therapeutic and/or preventative asthma treatments. Pending the availability of such therapies, it is essential to re-evaluate the current conventional "one-size-fits-all" approach to a more precise asthma management. Although challenging, identifying "treatable traits" that contribute to respiratory symptoms in individual patients with asthma may allow a more pragmatic approach to establish more personalised therapeutic goals.

Strategies for overcoming the biological barriers associated with the administration of inhaled monoclonal antibodies for lung diseases

INTRODUCTION

Monoclonal antibodies (mAbs) should be administered by inhalation rather than parenterally to improve their efficiency in lung diseases. However, the pulmonary administration of mAbs in terms of aerosol technology and the formulation for inhalation is difficult.

AREAS COVERED

The feasible or suitable strategies for overcoming the barriers associated with administering mAbs are described.

EXPERT OPINION

Providing mAbs via inhalation to individuals with lung disorders is still difficult. However, inhalation is a desirable method for mAb delivery. Inhaled mAb production needs to be well thought out. The illness, the patient group(s), the therapeutic molecule selected, its interaction with the biological barriers in the lungs, the formulation, excipients, and administration systems must all be thoroughly investigated. Therefore, to create inhaled mAbs that are stable and efficacious, it will be essential to thoroughly examine the problems linked to instability and protein aggregation. More excipients will also need to be manufactured, expanding the range of formulation design choices. Another crucial requirement is for novel carriers for topical delivery to the lungs since carriers might significantly enhance proteins' stability and pharmacokinetic profile.

Subsets of Eosinophils in Asthma, a Challenge for Precise Treatment

The existence of eosinophils was documented histopathologically in the first half of the 19th century. However, the term “eosinophils” was first used by Paul Ehrlich in 1878. Since their discovery and description, their existence has been associated with asthma, allergies, and antihelminthic immunity. Eosinophils may also be responsible for various possible tissue pathologies in many eosinophil-associated diseases. Since the beginning of the 21st century, the understanding of the nature of this cell population has undergone a fundamental reassessment, and in 2010, J. J. Lee proposed the concept of “LIAR” (Local Immunity And/or Remodeling/Repair), underlining the extensive immunoregulatory functions of eosinophils in the context of health and disease. It soon became apparent that mature eosinophils (in line with previous morphological studies) are not structurally, functionally, or immunologically homogeneous cell populations. On the contrary, these cells form subtypes characterized by their further development, immunophenotype, sensitivity to growth factors, localization, role and fate in tissues, and contribution to the pathogenesis of various diseases, including asthma. The eosinophil subsets were recently characterized as resident (rEos) and inflammatory (iEos) eosinophils. During the last 20 years, the biological therapy of eosinophil diseases, including asthma, has been significantly revolutionized. Treatment management has been improved through the enhancement of treatment effectiveness and a decrease in the adverse events associated with the formerly ultimately used systemic corticosteroids. However, as we observed from real-life data, the global treatment efficacy is still far from optimal. A fundamental condition, “sine qua non”, for correct treatment management is a thorough evaluation of the inflammatory phenotype of the disease. We believe that a better understanding of eosinophils would lead to more precise diagnostics and classification of asthma subtypes, which could further improve treatment outcomes. The currently validated asthma biomarkers (eosinophil count, production of NO in exhaled breath, and IgE synthesis) are insufficient to unveil super-responders among all severe asthma patients and thus give only a blurred picture of the adepts for treatment. We propose an emerging approach consisting of a more precise characterization of pathogenic eosinophils in terms of the definition of their functional status or subset affiliation by flow cytometry. We believe that the effort to find new eosinophil-associated biomarkers and their rational use in treatment algorithms may ameliorate the response rate to biological therapy in patients with severe asthma.

Development of an inhaled anti-TSLP therapy for asthma

Thymic stromal lymphopoietin (TSLP), an epithelial cell-derived cytokine, acts as a key mediator in airway inflammation and modulates the function of multiple cell types, including dendritic cells and group 2 innate lymphoid cells. TSLP plays a role in asthma pathogenesis as an upstream cytokine, and data suggest that TSLP blockade with the anti-TSLP monoclonal antibody, tezepelumab, could be efficacious in a broad asthma population. Currently approved asthma biologic therapies target allergic or eosinophilic disease and require phenotyping; therefore, an unmet need exists for a therapy that can address Type 2 (T2)-high and T2-low inflammation in asthma. All currently approved biologic treatments are delivered intravenously or subcutaneously; an inhaled therapy route that allows direct targeting of the lung with reduced systemic impact may offer advantages. Currently in development, ecleralimab (CSJ117) represents the first inhaled anti-TSLP antibody fragment that binds soluble TSLP and prevents TSLP receptor activation, thereby inhibiting further inflammatory signalling cascades. This anti-TSLP antibody fragment is being developed for patients with severe uncontrolled asthma despite standard of care inhaled therapy. A Phase IIa proof of concept study, using allergen bronchoprovocation as a model for asthma exacerbations, found that ecleralimab was well-tolerated and reduced allergen-induced bronchoconstriction in adult patients with mild asthma. These results suggest ecleralimab may be a promising, new therapeutic class for asthma treatment.

Clinical profiles of patients referred for biological therapy and major limitations in the qualification paths in a specialist asthma centre

Introduction

Despite the proven efficacy of biologics in the treatment of severe asthma, still a limited number of patients are included in the Polish therapeutic programme.

Aim

To identify major limitations in the qualification paths and predominant reasons leading to exclusion from available biologic treatments. The clinical profiles of patients referred for biologics were also examined.

Material and methods

Data on demographic characteristics, clinical profile, biomarkers, and medical history from one visit of patients that had been referred for qualification for biologics in 2018/2019 to the Barlicki Hospital (Poland) were collected. A comparison between eligible and ineligible patients was made.

Results

Within 2 years, only 116 patients had been referred to the biologic therapy of whom 93 (80%) had been suitable for the biologic programme. Criteria for the omalizumab programme included major limitations such as: frequent use of oral corticosteroids in the past, and serum total-IgE 30-1000 IU/ml, and for mepolizumab were blood eosinophil count (EOScount) > 350/μl and spirometric criterion. Ineligible patients had a significantly lower EOScount and better lung function than eligible individuals despite no significant differences in the number of exacerbations or quality of life between groups. A high percentage of ineligible patients had been referred to re-verify the diagnosis of severe asthma.

Conclusions

Potential limitations for biologic therapy include restrictive criteria limiting the group of patients to the most severe cases and referring patients with difficult-to-treat asthma without a differential diagnosis. Low awareness and knowledge among physicians who often are not familiar with qualification criteria require extensive education.

Narrative review to capture patients' perceptions and opinions about non-response and response to biological therapy for severe asthma

BACKGROUND

There are now many biological therapies to treat severe asthma. To assess which work best for which patient, we need to develop definitions of response. This narrative review aims to capture severe asthma patients' perceptions about non-response and response to biological therapy.

METHODS

Four bibliographic databases were searched from inception to September 2021. Grey literature was searched with the involvement of patient representatives. A thematic approach was used for synthesis. No qualitative studies specifically explore patients' perspectives on response to biological therapy for severe asthma. Three papers and one published asthma patient interview were included. Relevant grey literature was included from online discussion forums, blogs and social media websites.

RESULTS

Adult patients framed positive response to biological therapy in terms of reduced burden of disease and treatment. Both were multifaceted. Some patients experienced reduced benefit from biological therapy over time. There was a group of patients who described a limited response or non-response to biological therapy. This was framed within the context of continuing hospitalisation and oral corticosteroid treatment. The speed of onset of benefit was felt to be important by some.

CONCLUSIONS

Definitions of non-response and response need to be patient-centred, yet there is a complete lack of qualitative research focused on this topic. By combining relevant published and grey literature we have provided a description of adult patients' perceptions of response to biological therapy in severe asthma. We now need to understand the views of children and adolescents with severe asthma and their carers, and diverse patient experiences in real-world settings.

Monoclonal antibodies in the management of asthma: Dead ends, current status and future perspectives

Patients with moderate-to-severe asthma may now be treated using a variety of monoclonal antibodies that target key inflammatory cytokines involved in disease pathogenesis. Existing clinical data on anti-IgE, anti-IL-5 and other immunological pathways indicate these therapies to offer reduced exacerbation rates, improved lung function, greater asthma control and better quality of life. However, as several patients still do not achieve satisfactory clinical response with the antibodies available, many more biologics, aiming different immunological pathways, are under evaluation. This review summarizes recent data on existing and potential monoclonal antibodies in asthma. Recent advances have resulted in the registration of a new antibody targeting TSLP (tezepelumab), with others being under development. Some of the researched monoclonal antibodies (e.g. anti-IL-13 tralokinumab and lebrikizumab or anti-IL-17A secukinumab) have shown optimistic results in preliminary research; however, these have been discontinued in asthma clinical research. In addition, as available monoclonal antibody treatments have shown little benefit among patients with T₂-low asthma, research continues in this area, with several antibodies in development. This article summarizes the available pre-clinical and clinical data on new and emerging drugs for treating severe asthma, discusses discontinued treatments and outlines future directions in this area.

Identifying clinical and demographic characteristic differences between eosinophilic and non-eosinophilic asthma and detecting predictors of eosinophilic asthma among Egyptian asthmatic patients

Introduction

Asthma is a heterogenous disease with various phenotypes that is characterized by airway limitation due to bronchospasm and airway inflammation associated with excessive mucus secretion. Eosinophilic asthma subtype is described as a late onset asthma that presents with more severe respiratory symptoms, and with sputum eosinophilia ≥ 3%. In the current study, we aimed to identify the difference in the clinical and demographic characteristics between eosinophilic and non-eosinophilic asthma subtypes and to determine predictors of eosinophilic asthma.

Materials and methods

One hundred bronchial asthma patients with age ≥ 18 years were divided into two groups according to sputum eosinophilia. All patients were subjected to medical history, Asthma Control Test (ACT), spirometry, serum IgE level, skin prick testing (SPT), and nasal endoscopy to detect nasal polyposis and allergic signs.

Results

No statistical difference was found between eosinophilic and non-eosinophilic asthma patients regarding age, gender, and body mass index. Patients with sputum eosinophilia had more severe obstruction by spirometry, and positive SPT to food allergens, pollens, and latex with statistical significance (p values 0.001, 0.016, and 0.017 respectively). Additionally, patients with sputum eosinophilia had lower ACT score, higher serum IgE level and higher serum eosinophil count. Total IgE had the highest diagnostic accuracy for discrimination of sputum eosinophilia among asthma patients. Pollen allergy and the severity of airway obstruction by spirometry were independent predictors of eosinophilic asthma.

Conclusion

Patients with eosinophilic asthma had more severe airway obstruction, lower ACT scores, higher serum IgE level, and serum eosinophil count. Pollen allergy and obstructive pattern by spirometry were independent predictors of eosinophilic asthma.

Citrus junos Tanaka Peel Extract Ameliorates HDM-Induced Lung Inflammation and Immune Responses In Vivo

In the wake of the COVID-19 pandemic, lung disorders have become a major health concern for humans. Allergic asthma is the most prevalent form of asthma, and its treatments target the inflammation process. Despite significant developments in the diagnosis and management of allergic asthma, side effects are a major concern. Additionally, its extreme heterogeneity impedes the efficacy of the majority of treatments. Thus, newer, safer therapeutic substances, such as natural products, are desired. Citrus junos Tanaka has traditionally been utilized as an anti-inflammatory, sedative, antipyretic, and antitoxic substance. In this study, the protective effects of Citrus junos Tanaka peel extract (B215) against lung inflammation were examined, and efforts were made to understand the underlying protective mechanism using an HDM-induced lung inflammation murine model. The administration of B215 reduced immune cell infiltration in the lungs, plasma IgE levels, airway resistance, mucus hypersecretions, and cytokine production. These favorable effects alleviated HDM-induced lung inflammation by modulating the NF-κB signaling pathway. Hence, B215 might be a promising functional food to treat lung inflammation without adverse effects.

Tezepelumab for Patients with Severe Uncontrolled Asthma: A Systematic Review and Meta-Analysis

Tezepelumab is a human monoclonal antibody that blocks thymic stromal lymphopoietin, an epithelial-cell-derived cytokine implicated in the pathogenesis of asthma. It was approved by the United States Federal Drug Administration (US FDA) as an add-on maintenance treatment for patients with severe uncontrolled asthma in December 2021. We conducted a systematic review and meta-analysis to investigate the safety and efficacy of tezepelumab on forced expiratory volume (FEV1) (L), the rate of asthma exacerbations, health-related quality of life, fractional exhaled nitric oxide (FeNO) (ppb), and blood eosinophil count (cells/mL) in patients with severe, uncontrolled asthma. Mean changes for efficacy and proportions (safety) with their corresponding 95% confidence intervals (CIs) were used to provide pooled estimates. A total of six randomized controlled trials comprising 2667 patients were included, of whom 1610 were treated with tezepelumab and 1057 received placebo. The pooled analysis showed that tezepelumab treatment resulted in an improvement in FEV1 of 0.15 L (95% CI: 0.12 to 0.17), a reduction in the asthma exacerbation rate per year of 0.60 (95% CI: 0.51 to 0.70), and a reduction in FeNO of -12.41 ppb (95% CI: -14.28 to -10.53) when compared to placebo. Improvements in FEV1 and FeNO levels were maintained at 24 and 52 weeks. As for safety, patients did not experience a higher incidence of adverse drug reactions with tezepelumab (0.79 (95% CI: 0.55 to 1.12)) as compared to placebo. As for quality of life, different doses of the tezepelumab intervention group depicted non-significant improvement in the QoL, from 0.15 (95% CI: -0.09 to 0.38) for 70 mg, 0.18 (95% CI: -0.10 to 0.46) for 210 mg, 0.08 (95% CI: -0.16 to 0.32) for 280 mg as compared to the placebo. Tezepelumab significantly reduced exacerbation rates and improved FEV1 with an acceptable safety profile.

Dupilumab Efficacy and Safety as an Add-On Therapy in Uncontrolled Asthma Patients: A Systematic Review

Asthma is a heterogeneous chronic inflammatory condition affecting the lung. Standard treatment, a high-dose inhaled corticosteroid (ICS) and long-acting bronchodilator (LABA), effectively manages asthma in most individuals. However, 5%-10% of individuals with asthma were ineffective with those treatments. Recent RCTs suggested that Dupilumab posed potential as an add-on therapy. This systematic review aims to support the efficacy (the annualized rate of severe asthma exacerbation and increase in FEV1) and the safety of Dupilumab as an add-on therapy in uncontrolled asthma patients. We used "(Asthma) AND (Dupilumab)" as keywords on PubMed and ScienceDirect. We included only RCT design studies comparing the efficacy and safety of Dupilumab with a placebo in uncontrolled asthma patients. The placebo was ICS and LABA or oral glucocorticoids. This paper included five RCTs with 3400 participants, and their quality was assessed using Critical Appraisal Tools Program (CASP) tools. We conducted a meta-analysis to calculate the pooled risk ratio (RR). In addition, we used Mantel-Haenszel with 95% confidence intervals for dichotomous data. Furthermore, we used a random-effects model to count for interstudy heterogeneity. Then, we processed data using Revman 5.4. Dupilumab as an add-on therapy significantly showed a consistent effect in lower the annualized rate of severe asthma exacerbation (RR= 0.46; 95% CI 0.36- 0.58; p=0.007) and increased FEV1 compared to placebo. In addition, the most common adverse effect of using Dupilumab were injection site reaction, upper respiratory tract infections, and eosinophilia. In conclusion, Dupilumab is safe and well-tolerated as moderate-to-severe uncontrolled asthma add-on therapy

Characterization of Patients in the International Severe Asthma Registry with High Steroid Exposure Who Did or Did Not Initiate Biologic Therapy

Background

Many severe asthma patients with high oral corticosteroid exposure (HOCS) often do not initiate biologics despite being eligible. This study aimed to compare the characteristics of severe asthma patients with HOCS who did and did not initiate biologics.

Methods

Baseline characteristics of patients with HOCS (long-term maintenance OCS therapy for at least 1 year, or ≥4 courses of steroid bursts in a year) from the International Severe Asthma Registry (ISAR; https://isaregistries.org/), who initiated or did not initiate biologics (anti-lgE, anti-IL5/5R or anti-IL4R), were described at the time of biologic initiation or registry enrolment. Statistical relationships were tested using Pearson’s chi-squared tests for categorical variables, and t-tests for continuous variables, adjusting for potential errors in multiple comparisons.

Results

Between January 2015 and February 2021, we identified 1412 adult patients with severe asthma from 19 countries that met our inclusion criteria of HOCS, of whom 996 (70.5%) initiated a biologic and 416 (29.5%) did not. The frequency of biologic initiation varied across geographical regions. Those who initiated a biologic were more likely to have higher blood eosinophil count (483 vs 399 cells/µL, p=0.003), serious infections (49.0% vs 13.3%, p<0.001), nasal polyps (35.2% vs 23.6%, p<0.001), airflow limitation (56.8% vs 51.8%, p=0.013), and uncontrolled asthma (80.8% vs 73.2%, p=0.004) despite greater conventional treatment adherence than those who did not start a biologic. Both groups had similar annual asthma exacerbation rates in the previous 12 months (5.7 vs 5.3, p=0.147).

Conclusion

Around one third of severe HOCS asthma patients did not receive biologics despite a similar high burden of asthma exacerbations as those who initiated a biologic therapy. Other disease characteristics such as eosinophilic phenotype, serious infectious events, nasal polyps, airflow limitation and lack of asthma control appear to dictate biologic use.

The Role of Systems Biology in Deciphering Asthma Heterogeneity

Asthma is one of the most common and lifelong and chronic inflammatory diseases characterized by inflammation, bronchial hyperresponsiveness, and airway obstruction episodes. It is a heterogeneous disease of varying and overlapping phenotypes with many confounding factors playing a role in disease susceptibility and management. Such multifactorial disorders will benefit from using systems biology as a strategy to elucidate molecular insights from complex, quantitative, massive clinical, and biological data that will help to understand the underlying disease mechanism, early detection, and treatment planning. Systems biology is an approach that uses the comprehensive understanding of living systems through bioinformatics, mathematical, and computational techniques to model diverse high-throughput molecular, cellular, and the physiologic profiling of healthy and diseased populations to define biological processes. The use of systems biology has helped understand and enrich our knowledge of asthma heterogeneity and molecular basis; however, such methods have their limitations. The translational benefits of these studies are few, and it is recommended to reanalyze the different studies and omics in conjugation with one another which may help understand the reasons for this variation and help overcome the limitations of understanding the heterogeneity in asthma pathology. In this review, we aim to show the different factors that play a role in asthma heterogeneity and how systems biology may aid in understanding and deciphering the molecular basis of asthma.

Gulf Asthma Diagnosis and Management in Adults: Expert Review and Recommendations

The prevalence and incidence of asthma are increasing globally because of genetic and environmental influences. Prevalence of asthma in the Gulf has been reported to range from 4.7% to 32.0% and has a substantial economic burden. In this paper, we summarize current asthma management guidance for adults, present insights, and recommendations by key opinion leaders (KOLs) in the Gulf region, and key performance indicators for guiding clinical practice for asthma diagnosis, management, and treatment in the Gulf. While it is recommended that the Global Initiative for Asthma (GINA) guidelines should be followed wherever possible for the management of asthma, KOLs in the Gulf region have presented additional recommendations based on regional challenges and insights. There is a need for better diagnosis using objective testing, increased efforts in tackling the burden of comorbidities in the region, and greater provision of the necessary tools for phenotyping severe asthma. Furthermore, there is a need for greater education for physicians regarding asthma treatment, including the importance of inhaled-corticosteroid-containing controller medication. Regionally, there is also a need for specialist asthma clinics and asthma educators, which would serve to educate physicians and their patients as well as to improve the management of patients. Finally, the use of asthma registries, digital devices, and electronic templates would be of benefit in the management of asthma patients in the region.

Targeting TSLP in Asthma

Thymic stromal lymphopoietin (TSLP) is an epithelial cell-derived cytokine implicated in the initiation and persistence of inflammatory pathways in asthma. Released in response to a range of epithelial insults (eg, allergens, viruses, bacteria, pollutants, and smoke), TSLP initiates multiple downstream innate and adaptive immune responses involved in asthma inflammation. Inhibition of TSLP is postulated to represent a novel approach to treating the diverse phenotypes and endotypes of asthma. Tezepelumab, the TSLP inhibitor farthest along in clinical development, is a human monoclonal antibody (IgG2λ) that binds specifically to TSLP, preventing interactions with its heterodimeric receptor. Results of recently published phase 2 and 3 studies, reviewed in this article, provide evidence of the safety and efficacy of tezepelumab that builds on initial findings. Tezepelumab is safe, well tolerated, and provides clinically meaningful improvements in asthma control, including reduced incidence of exacerbations and hospitalizations in patients with severe asthma. Clinical benefits were associated with reductions in levels of a broad spectrum of cytokines (eg, interleukin [IL]-5, IL-13) and baseline biomarkers (eg, blood eosinophils, immunoglobulin [Ig]E, fractional exhaled nitric oxide [FeNO]) and were observed across a range of severe asthma phenotypes (ie, eosinophilic and non-eosinophilic). These data strengthen the notion that anti-TSLP elicits broad inhibitory effects on pathways that are key to asthma inflammation rather than on narrower inhibition of individual downstream factors. This review presents the rationale for targeting TSLP to treat asthma, as well as the clinical effects of TSLP blockade on asthma outcomes, biomarkers of disease activity, airway inflammation, lung physiology, and patient symptoms.

Specific Therapy for T2 Asthma

Asthma is a disease with high incidence and prevalence, and its severe form accounts for approximately 10% of asthmatics. Over the last decade, the increasing knowledge of the mechanisms underlying the disease allowed the development of biological drugs capable of sufficiently controlling symptoms and reducing the use of systemic steroids. The best-known mechanisms are those pertaining to type 2 inflammation, for which drugs were developed and studied. Those biological treatments affect crucial points of bronchial inflammation. Among the mechanisms explored, there were IgE (Omalizumab), interleukin 5 (Mepolizumab and Reslizumab), interleukin 5 receptor alpha (Benralizumab) and interleukin 4/13 receptor (Dupilumab). Under investigation and expected to be soon commercialized is the monoclonal antibody blocking the thymic stromal lymphopoietin (Tezepelumab). Seemingly under study and promising, are anti-interleukin-33 (itepekimab) and anti-suppressor of tumorigenicity-2 (astegolimab). With this study, we want to provide an overview of these drugs, paying particular attention to their mechanism of action, the main endpoints reached in clinical trials, the main results obtained in real life and some unclear points regarding their usage.

Real-World Efficacy of Treatment with Benralizumab, Dupilumab, Mepolizumab and Reslizumab for Severe Asthma: A Systematic Review and Meta-analysis

BACKGROUND

Severe asthma is a major cause of morbidity. Some patients may benefit from biological therapies. Most evaluations of these treatments are derived from randomised controlled trials (RCTs), but few patients are eligible for these trials. Studies involving more diverse groups of participants exist but there is a lack of precise pooled estimates.

OBJECTIVE

This systematic review aims to evaluate the real-world efficacy of recently and nearly licensed biological therapies for severe asthma to assess the generalisability of the RCT data.

METHODS

Clinical outcomes including exacerbation rate, oral corticosteroid (OCS) usage, forced expiratory volume in 1 second (FEV₁ ) and fractional exhaled nitric oxide (FeNO) were examined. Studies were assessed for risk of bias using the Critical Appraisal Skills Programme (CASP) checklist tool. The certainty of evidence was assessed using GRADE.

RESULTS

A total of 21 studies examining biologicals in real-world settings were identified, they mostly focused on benralizumab and mepolizumab. The introduction of biologicals reduced the annualised exacerbation rate significantly by -3.79 (95% CI -4.53, -3.04), -3.17 (95% CI -3.74, -2.59) and -6.72 (95% CI -8.47, -4.97) with benralizumab, mepolizumab and reslizumab respectively. Likewise, improvements were observed in FEV₁ (0.17 L 95% CI 0.11, 0.24) and FeNO (-14.23 ppb 95% CI -19.71, -8.75) following treatment with mepolizumab. After treatment with benralizumab there was an increase in FEV₁ (0.21 L 95% CI 0.08, 0.34).

CONCLUSIONS

These data demonstrate that anti-IL5 biologicals may improve the clinical outcomes of patients with severe asthma in a clinic environment with similar effect sizes to RCTs. The data were mainly retrospective and unadjusted, so estimated effect sizes may not be reliable. More data is needed to acquire accurate effect estimates in different subpopulations of patients.

Effective Management of Severe Asthma with Biologic Medications in Adult Patients: A Literature Review and International Expert Opinion

Severe asthma often remains uncontrolled despite effective treatments and evidence-based guidelines. A group of global experts in asthma and biologic medications from 9 countries considered the most relevant clinical variables to manage severe asthma in adult patients and guide treatment choice. The resulting recommendations address the investigation of biomarker levels (blood eosinophil count along with fractional concentration of exhaled nitric oxide [FeNO]), clinical features (oral corticosteroid [OCS] dependence, specific comorbid disease entities associated with severe type 2 asthma), and safety considerations. Current evidence suggests that biomarkers, including both blood or sputum eosinophil counts as well as FeNO, add prognostic and predictive value and should be measured in all patients with severe asthma. OCS use is an important factor in biologic selection, especially given the documented ability of some biologics to reduce OCS dependence. Comorbid diseases and relevant safety considerations to each biologic should also be considered. More data are needed to determine whether biomarker profiles identify patients suited to one biologic versus another as limited data support differential predictors of response. Further prospective head-to-head trials and post hoc analyses of clinical trial data are warranted. The authors believe that these recommendations have value as they offer expert opinion to assist health care providers in making difficult decisions regarding the quality of care in severe, type 2 asthma with biologic medications. They remain conditional and are based on limited data owing to a lack of head-to-head comparisons.

Clinical and Lung Function Outcomes After Anti-IgE or Anti-IL5 Therapy in Severe Asthma

Background

Although there have been indirect comparisons of the relative efficacy of mepolizumab (anti-IL-5) and benralizumab (anti-IL-5Rα) in severe asthma patients, long-term direct head-to-head comparisons are lacking. Here, we (i) examined the effect of mepolizumab, benralizumab, and omalizumab on symptom control and lung function parameters over time; and (ii) compared the efficacy of mepolizumab and benralizumab on symptom control and lung function outcomes.

Methods

This was a retrospective study of patients with severe asthma taking anti-IgE (omalizumab; n = 24), anti-IL5 (mepolizumab, n = 23), or anti-IL-Rα (benralizumab; n = 12) therapy. Data were extracted on (i) Asthma Control Questionnaire (ACQ-5) scores; (ii) forced expiratory volume over 1 second (FEV₁); and (iii) peak expiratory flow rate (PEFR) at 4–6 months and 1 year and documented reductions in exacerbations. Clinical and lung function outcomes were compared between patients taking mepolizumab and benralizumab and over time.

Results

There were significant decreases in ACQ-5 scores (3.3 ± 0.93 to 1.7 ± 0.98 for mepolizumab, 3.5 ± 0.72 to 1.6 ±0.89 for benralizumab, and 3.5 ± 0.95 to 1.7 ± 1.1 for omalizumab; t-test, all p < 0.0001) but not increases in FEV₁ and PEFR for all three agents after 4–6 months of therapy, which persisted but did not decrease further at one year. There were trends toward a greater percentage increase in FEV₁ and PEFR from baseline and a decrease in the number of exacerbations in patients taking benralizumab than those taking mepolizumab.

Conclusion

Although limited by a small sample size, this real-world, head-to-head comparison of mepolizumab and benralizumab is consistent with comparative data on asthma biologicals and indirect comparisons showing no major difference in efficacy. The study also generates new testable hypotheses about the efficacy of asthma biologicals in different patient populations.

Effects of Therapeutic Antibodies on Gene and Protein Signatures in Asthma Patients: A Comparative Systematic Review

Several biologic therapies that target inflammatory modulators are now used for treating patients with uncontrolled, severe asthma. Knowledge about how this type of treatment modifies the molecular milieu is rapidly increasing. Thus, this systematic review aimed to compile the reported effects of therapeutic antibodies on the transcriptome or proteome of asthma patients. Studies of asthmatic patients under biological treatment describing transcriptomic or proteomic changes upon treatment were included. Preclinical or single gene/protein studies were not considered. PubMed and Scopus search was performed in August and September 2021. Following PRISMA guidelines and GRADE recommendations, we selected 12 studies on gene or protein expression changes in patients treated with the antibodies currently approved by EMA and the FDA. All studies were at low risk of bias as per the RoB2 tool. Different gene clusters have been identified to change upon omalizumab treatment, found a reduction in eosinophil-associated gene signatures after benralizumab treatment, and protein profiles were different in patients treated with mepolizumab and in those treated with benralizumab. The main potential biomarkers proposed by the selected studies are shown. These results may contribute to discovering biomarkers of response and selecting the best therapy for each patient.

The nitroxide/antioxidant 3-carbamoyl proxyl attenuates disease severity in murine models of severe asthma

Asthma is characterized by airway inflammation, hyper-responsiveness, symptoms of dyspnea, wheezing and coughing. In most patients, asthma is well controlled using inhaled corticosteroids and bronchodilators. A minority of patients with asthma develop severe disease, which is frequently only partially responsive or even resistant to treatment with corticosteroids. Severe refractory asthma is associated with structural changes in the airways, termed "airway remodeling", and/or with neutrophilic rather than eosinophilic airway inflammation. While oxidative stress plays an important role in the pathophysiology of asthma, cyclic nitroxide stable radicals, which are unique and efficient catalytic antioxidants, effectively protect against oxidative injury. We have demonstrated that the nitroxide 3-carbamoyl proxyl (3-CP) attenuates airway inflammation and hyperresponsiveness in allergic asthma as well as bleomycin-induced fibrosis both using murine models, most probably through modulation of oxidative stress. The present study evaluates the effect of 3-CP on airway inflammation and remodeling using two murine models of severe asthma where mice are sensitized and challenged either by ovalbumin (OVA) or by house dust mite (HDM). 3-CP was orally administered during the entire period of the experiment or during the challenge period alone where its effect was compared to that of dexamethasone. The induced increase by OVA and by HDM of BALf cell counts, airway hyperresponsiveness, fibrosis, transforming growth factor-beta (TGF-β) levels in BALf and protein nitration levels of the lung tissue was significantly reduced by 3-CP. The effect of 3-CP, using two different murine models of severe asthma, is associated at least partially with attenuation of oxidative stress and with TGF-β expression in the lungs. The results of this study suggest a potential use of 3-CP as a novel therapeutic agent in different forms of severe asthma.

Environmental allergens house dust mite-induced asthma is associated with ferroptosis in the lungs

Previous studies have indicated that allergens such as house dust mites (HDM) in the environment can induce allergic asthma. Ferroptosis is a newly discovered form of regulatory cell death characterized by aberrant lipid peroxidation and the accumulation of reactive oxygen species (ROS) in cells. However, whether ferroptosis participates in the pathological process of asthma remains to be elucidated. The present study used a HDM-induced mouse asthma model to determine the effect of HDM exposure on allergic asthma and its underlying mechanisms. Female BALB/c mice were intranasally exposed to HDM to induce allergic asthma. Airway hyperresponsiveness (AHR), lung inflammation, mucus secretion, IgE levels, cytokine levels and inflammatory cell counts in bronchoalveolar lavage fluid (BALF) were investigated. In addition, the morphological changes of mitochondria, ROS levels, glutathione (GSH) levels and changes in ferroptosis pathway proteins were also determined in murine lungs. As a result, HDM exposure significantly increased AHR, inflammatory cell infiltration and mucus secretion around the airways. Furthermore, elevated IgE levels in the BALF, lung eosinophilia and a concomitant increase in IL-13 and IL-5 levels in BALF were observed. HDM inhalation increased ROS and decreased GSH levels in the lungs. HDM inhalation induced dysmorphic small mitochondria with decreased crista, as well as condensed, ruptured outer membranes. Western blotting demonstrated that the activities of glutathione peroxidase 4 and catalytic subunit solute carrier family 7 member 11 were significantly decreased, and that protein expression levels of acyl-CoA synthetase long-chain family member 4 and 15 lipoxygenase 1 were upregulated compared with mice in the normal control group. Overall, these results indicated that the AHR, airway inflammation, lipid peroxidation and ROS levels increased in HDM-induced asthma, and that HDM inhalation induced ferroptosis in the lungs, which helped to form an improved understanding of the pathogenesis of allergic asthma.

Biological therapies targeting the type 2 inflammatory pathway in severe asthma (Review)

Asthma is a variable chronic respiratory disease characterized by airway inflammation and hyperresponsiveness, bronchoconstriction, and mucus hypersecretion. While most patients with asthma achieve good control of the disease, 5-10% experience severe symptoms and recurrent exacerbation despite the maximal offered therapy with inhaled corticosteroids and long acting bronchodilators. In previous years, novel biological therapies have become available, and various asthma phenotypes that are characterized by specific biomarkers have been identified. Currently approved biological agents target inflammatory molecules of the type 2 inflammatory pathway, and are effective at decreasing the frequency of asthma attacks, controlling symptoms and decreasing use of systemic steroids. The present study reviewed the effectiveness and safety profile of the currently approved biological drugs and provided an overview of the assessment of patients with severe asthma who are potentially suitable for biological therapy, in order to help clinicians to select the most appropriate biological agent.

Molecular Targets for Biological Therapies of Severe Asthma: Focus on Benralizumab and Tezepelumab

Asthma is a heterogeneous respiratory disease characterized by usually reversible bronchial obstruction, which is clinically expressed by different phenotypes driven by complex pathobiological mechanisms (endotypes). In recent years several molecular effectors and signaling pathways have emerged as suitable targets for biological therapies of severe asthma, refractory to standard treatments. Indeed, various therapeutic mono-clonal antibodies currently allow one to intercept at different levels the chain of pathogenic events leading to type 2 (T2) airway inflammation. Pro-allergic immunoglobulin E (IgE) is the first molecule against which an anti-asthma monoclonal antibody (omalizumab) was developed; today other targets are successfully being exploited by biological treatments for severe asthma. In particular, pro-eosinophilic interleukin 5 (IL-5) can be targeted by mepolizumab or reslizumab, whereas benralizumab is a selective blocker of IL-5 receptor, and IL-4 and IL-13 can be targeted by dupilumab. Besides these drugs, which are already available in medical practice, other biologics are under clinical development such as those targeting innate cytokines, including the alarmin thymic stromal lymphopoietin (TSLP), which plays a key role in the pathogenesis of type 2 asthma. Therefore, ongoing and future biological therapies are significantly changing severe asthma management on a global level. These new therapeutic options make it possible to implement phenotype/endotype-specific treatments, which are delineating personalized approaches precisely addressing the individual traits of asthma pathobiology. The aim of the study is to review the immunopathology and treatment efficacy for severe asthma and focused on new biological agents with benralizumab (anti-IL-5) and tezepelumab (anti-TSLP).

Long noncoding RNA LINC-PINT retards the abnormal growth of airway smooth muscle cells via regulating the microRNA-26a-5p/PTEN axis in asthma

BACKGROUND

Asthma is a chronic respiratory disease worldwide. This study aimed to explore the functions of the long noncoding RNA LINC-PINT (LINC-PINT) in asthma and to determine its underlying molecular mechanisms.

METHODS

Rat asthma model was established with ovalbumin sensitization and challenge. The serum level of IgE, airway hyperresponsiveness (AHR), airway inflammation, and pathological changes of lung were evaluated. Airway smooth muscle cells (ASMCs) were stimulated with platelet-derived growth factor-BB (PDGF-BB) to mimic the asthma-like condition at cellular level. QRT-PCR was performed to detect the expression of LINC-PINT, microRNA-26a-5p (miR-26a-5p), and PTEN. MTT and transwell assays were performed to measure the viability and migration of ASMCs. The protein expression of airway remodelling marker MMP-1 and MMP-9 was measured by western blot. The interactions among LINC-PINT, miR-26a-5p, and PTEN were determined by dual-luciferase reporter assay.

RESULTS

The expression of LINC-PINT and PTEN was decreased, while miR-26a-5p expression was increased in PDGF-BB-stimulated ASMCs. In vivo, overexpression of LINC-PINT decreased the serum level of IgE, AHR, airway inflammation, and pathological changes of lung in asthma rat model. In vitro, up-regulation of LINC-PINT decreased the viability, migration, and MMP-1 and MMP-9 protein expression in PDGF-BB-stimulated ASMCs. Dual-luciferase reporter assay determined that LINC-PINT targeted miR-26a-5p, and miR-26a-5p targeted PTEN in ASMCs. Feedback approaches confirmed that miR-26a-5p up-regulation or PTEN down-regulation reversed the suppressive effect of LINC-PINT overexpression on the abnormal growth of ASMCs.

CONCLUSIONS

LINC-PINT overexpression retarded the abnormal growth of ASMCs by regulating the miR-26a-5p/PTEN axis, offering a potential therapeutic target for asthma.

Current long-acting muscarinic antagonists for the treatment of asthma

INTRODUCTION

The role of long-acting muscarinic antagonists (LAMAs) is well established in uncontrolled asthma, but not in milder stages.

AREAS COVERED

This review examines the main randomized controlled trials (RCTs) that have investigated LAMAs administered as monotherapy or in combination to asthmatic patients, according to the different phenotypes. It offers an overview of the role of LAMAs or their fixed dose combinations (FDCs) in the treatment across all the different stages of asthma.

EXPERT OPINION

Tiotropium is now widely recognized as treatment for moderate to severe uncontrolled asthma (step 4-5) in adults and children. The most recent new evidence is: a) in adults, three different LAMA/long-acting β₂-agonist (LABA)/inhaled corticosteroid (ICS) FDCs have been recently approved, extending the treatment options for these patients; b) therapy with LAMAs does not depend on patient's Th2 status and justifies the indication regardless of patient's phenotyping; c) in the milder stages, the high variability of response to LAMAs and the lack of a good phenotyping of patients represents the main obstacle in prescribing LAMAs. A better characterization of parasympathetic tone activity could improve LAMAs prescription.

T2-High Endotype and Response to Biological Treatments in Patients with Bronchiectasis

Although bronchiectasis pathophysiology has been historically understood around the presence of airway neutrophilic inflammation, recent experiences are consistent with the identification of a type 2 inflammation (T2) high endotype in bronchiectasis. In order to evaluate prevalence and clinical characteristics of bronchiectasis patients with a T2-high endotype and explore their response to biologicals, two studies were carried out. In a cross-sectional study, bronchiectasis adults without asthma underwent clinical, radiological, and microbiological assessment, along with blood eosinophils and oral fractional exhaled nitric oxide (FeNO) evaluation, during stable state. Prevalence and characteristics of patients with a T2- high endotype (defined by the presence of either eosinophils blood count ≥300 cells·µL⁻¹ or oral FeNO ≥ 25 dpp) were reported. A case series of severe asthmatic patients with concomitant bronchiectasis treated with either mepolizumab or benralizumab was evaluated, and patients’ clinical data pre- and post-treatment were analyzed up to 2 years of follow up. Among bronchiectasis patients without asthma enrolled in the cross-sectional study, a T2-high endotype was present in 31% of them. These patients exhibited a more severe disease, high dyspnea severity, low respiratory function, and high impact on quality of life. Among the five patients with severe eosinophilic asthma and concomitant bronchiectasis included in the series, treatment with either mepolizumab or benralizumab significantly reduced the exacerbation rate with an effect that persists for up to 2 years of follow up. If validated across different settings, our data suggest the need to design randomized controlled trials on biological treatments targeting the T2-high endotype in bronchiectasis patients.

Can GPCRs Be Targeted to Control Inflammation in Asthma?

Historically, the drugs used to manage obstructive lung diseases (OLDs), asthma, and chronic obstructive pulmonary disease (COPD) either (1) directly regulate airway contraction by blocking or relaxing airway smooth muscle (ASM) contraction or (2) indirectly regulate ASM contraction by inhibiting the principal cause of ASM contraction/bronchoconstriction and airway inflammation. To date, these tasks have been respectively assigned to two diverse drug types: agonists/antagonists of G protein-coupled receptors (GPCRs) and inhaled or systemic steroids. These two types of drugs "stay in their lane" with respect to their actions and consequently require the addition of the other drug to effectively manage both inflammation and bronchoconstriction in OLDs. Indeed, it has been speculated that safety issues historically associated with beta-agonist use (beta-agonists activate the beta-2-adrenoceptor (β₂AR) on airway smooth muscle (ASM) to provide bronchoprotection/bronchorelaxation) are a function of pro-inflammatory actions of β₂AR agonism. Recently, however, previously unappreciated roles of various GPCRs on ASM contractility and on airway inflammation have been elucidated, raising the possibility that novel GPCR ligands targeting these GPCRs can be developed as anti-inflammatory therapeutics. Moreover, we now know that many GPCRs can be "tuned" and not just turned "off" or "on" to specifically activate the beneficial therapeutic signaling a receptor can transduce while avoiding detrimental signaling. Thus, the fledging field of biased agonism pharmacology has the potential to turn the β₂AR into an anti-inflammatory facilitator in asthma, possibly reducing or eliminating the need for steroids.

Biomarkers for Severe Asthma: Lessons From Longitudinal Cohort Studies

Severe asthma (SA) is a heterogeneous disease characterized by uncontrolled symptoms, frequent exacerbations, and lung function decline. The discovery of phenotypes and endotypes of SA significantly improves our understanding of its pathophysiology and allows the advent of biologics blocking multiple molecular targets. The advances have mainly been made in type 2-high asthma associated with elevated type 2 inflammatory biomarkers such as immunoglobulin E (IgE), interleukins (IL)-4, IL-5, and IL-13. Previous clinical trials have demonstrated that type 2 biomarkers, including blood/sputum eosinophils and the fraction of exhaled nitric oxide (FeNO), were correlated to severe airway inflammation, persistent symptoms, frequent exacerbations, and the clinical efficacy of these biomarkers in predicting treatment outcomes of type 2-targeting biologics. However, it is well known that type 2 inflammation is partially attributable to the pathogenesis of SA. Although some recent studies have suggested that type 2-low and mixed phenotypes of asthma are important contributors to the heterogeneity of SA, many questions about these non-type 2 asthma phenotypes remain to be solved. Consequently, many efforts to investigate and find novel biomarkers for SA have also made in their methods. Many cross-sectional experimental studies in large-scale cohorts and randomized clinical trials have proved their value in understanding SA. More recently, real-world cohort studies have been in the limelight for SA research, which is unbiased and expected to give us an answer to the unmet needs of the heterogeneity of SA.

Asthma in the Precision Medicine Era: Biologics and Probiotics

Asthma is a major global health issue. Over 300 million people worldwide suffer from this chronic inflammatory airway disease. Typical clinical symptoms of asthma are characterized by a recurrent wheezy cough, chest tightness, and shortness of breath. The main goals of asthma management are to alleviate asthma symptoms, reduce the risk of asthma exacerbations, and minimize long-term medicinal adverse effects. However, currently available type 2 T helper cells (Th2)-directed treatments are often ineffective due to the heterogeneity of the asthma subgroups, which manifests clinically with variable and poor treatment responses. Personalized precision therapy of asthma according to individualized clinical characteristics (phenotype) and laboratory biomarkers (endotype) is the future prospect. This mini review discusses the molecular mechanisms underlying asthma pathogenesis, including the hot sought-after topic of microbiota, add-on therapies and the potential application of probiotics in the management of asthma.