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

Impact of pre-biologic impairment on meeting domain-specific biologic responder definitions in patients with severe asthma

BACKGROUND

There is little agreement on clinically useful criteria for identifying real-world responders to biologic treatments for asthma.

OBJECTIVE

To investigate the impact of pre-biologic impairment on meeting domain-specific biologic responder definitions in adults with severe asthma.

METHODS

This was a longitudinal, cohort study across 22 countries participating in the International Severe Asthma Registry (https://isaregistries.org/) between May 2017 and January 2023. Change in 4 asthma domains (exacerbation rate, asthma control, long-term oral corticosteroid [LTOCS] dose, and lung function) was assessed from biologic initiation to 1 year post-treatment (minimum 24 weeks). Pre- to post-biologic changes for responders and nonresponders were described along a categorical gradient for each domain derived from pre-biologic distributions (exacerbation rate: 0 to 6+/y; asthma control: well controlled to uncontrolled; LTOCS: 0 to >30 mg/d; percent-predicted forced expiratory volume in 1 second [ppFEV1]: <50% to ≥80%).

RESULTS

Percentage of biologic responders (ie, those with a category improvement pre- to post-biologic) varied by domain and increased with greater pre-biologic impairment, increasing from 70.2% to 90.0% for exacerbation rate, 46.3% to 52.3% for asthma control, 31.1% to 58.5% for LTOCS daily dose, and 35.8% to 50.6% for ppFEV1. The proportion of patients having improvement post-biologic tended to be greater for anti-IL-5/5R compared with for anti-IgE for exacerbation, asthma control, and ppFEV1 domains, irrespective of pre-biologic impairment.

CONCLUSION

Our results provide realistic outcome-specific post-biologic expectations for both physicians and patients, will be foundational to inform future work on a multidimensional approach to define and assess biologic responders and response, and may enhance appropriate patient selection for biologic therapies.

TRIAL REGISTRATION

The ISAR database has ethical approval from the Anonymous Data Ethics Protocols and Transparency (ADEPT) committee (ADEPT0218) and is registered with the European Union Electronic Register of Post-Authorization studies (ENCEPP/DSPP/23720). The study was designed, implemented, and reported in compliance with the European Network Centres for Pharmacoepidemiology and Pharmacovigilance (ENCEPP) Code of Conduct (EUPAS38288) and with all applicable local and international laws and regulation, and registered with ENCEPP (https://www.encepp.eu/encepp/viewResource.htm?id=38289). Governance was provided by ADEPT (registration number: ADEPT1220).

Difficult-To-Treat and Severe Asthma: Can Real-World Studies On Effectiveness of Biological Treatments Change the Lives of Patients?

Many different phenotypes that characterize severe asthma are supported by intricate pathomechanisms called endotypes. The latter are driven by molecular interactions, mediated by intercellular networks. With regard to the biological treatments of either allergic or non-allergic eosinophilic type 2 asthma, real-world studies have confirmed the positive effects of currently available antibodies directed against immunoglobulins E (IgE), interleukin-5 (IL-5) and its receptor, as well as the receptors of interleukins-4 (IL-4) and 13 (IL-13). The best way to treat severe asthma should be chosen based on the peculiar phenotypic and endotypic traits of each patient. This will lead to relevant improvements in both clinical and functional outcomes. In particular, biological therapies can change the lives of asthma patients with a strong impact on quality of life. Unfortunately, patients with severe non-type-2 asthma, who continue to have pertinent unmet needs, are not receiving satisfactory advances within the context of biological treatments. It is also hopeful that in the next future new therapeutic strategies will be specifically implemented for these people, perhaps offering them the opportunity to improve their current, mostly inadequate asthma management.

Treatable traits models of care

Treatable traits is a personalized approach to the management of respiratory disease. The approach involves a multidimensional assessment to understand the traits present in individual patients. Traits are phenotypic and endotypic characteristics that can be identified, are clinically relevant and can be successfully treated by therapy to improve clinical outcomes. Identification of traits is followed by individualized and targeted treatment to those traits. First proposed for the management of asthma and chronic obstructive pulmonary disease (COPD) the approach is recommended in many other areas of respiratory and now immunology medicine. Models of care for treatable traits have been proposed in different diseases and health care setting. In asthma and COPD traits are identified in three domains including pulmonary, extrapulmonary and behavioural/lifestyle/risk-factors. In bronchiectasis and interstitial lung disease, a fourth domain of aetiological traits has been proposed. As the core of treatable traits is personalized and individualized medicine; there are several key aspects to treatable traits models of care that should be considered in the delivery of care. These include person centredness, consideration of patients' values, needs and preferences, health literacy and engagement. We review the models of care that have been proposed and provide guidance on the engagement of patients in this approach to care.

Developments in the Management of Severe Asthma in Children and Adolescents: Focus on Dupilumab and Tezepelumab

Severe asthma in children and adolescents exerts a substantial health, financial, and societal burden. Severe asthma is a heterogeneous condition with multiple clinical phenotypes and underlying inflammatory patterns that might be different in individual patients. Various add-on treatments have been developed to treat severe asthma, including monoclonal antibodies (biologics) targeting inflammatory mediators. Biologics that are currently approved to treat children (≥ 6 years of age) or adolescents (≥ 12 years of age) with severe asthma include: anti-immunoglobulin E (omalizumab), anti-interleukin (IL)-5 (mepolizumab), anti-IL5 receptor (benralizumab), anti-IL4/IL13 receptor (dupilumab), and antithymic stromal lymphopoietin (TSLP) (tezepelumab). However, access to these targeted treatments varies across countries and relies on few and crude indicators. There is a need for better treatment stratification to guide which children might benefit from these treatments. In this narrative review we will assess the most recent developments in the treatment of severe pediatric asthma, as well as potential biomarkers to assess treatment efficacy for this patient population.

Definitions of non-response and response to biological therapy for severe asthma: a systematic review

Background

Biologics have proven efficacy for patients with severe asthma but there is lack of consensus on defining response. We systematically reviewed and appraised methodologically developed, defined and evaluated definitions of non-response and response to biologics for severe asthma.

Methods

We searched four bibliographic databases from inception to 15 March 2021. Two reviewers screened references, extracted data, and assessed methodological quality of development, measurement properties of outcome measures and definitions of response based on COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN). A modified GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach and narrative synthesis were undertaken.

Results

13 studies reported three composite outcome measures, three asthma symptoms measures, one asthma control measure and one quality of life measure. Only four measures were developed with patient input; none were composite measures. Studies utilised 17 definitions of response: 10 out of 17 (58.8%) were based on minimal clinically important difference (MCID) or minimal important difference (MID) and 16 out of 17 (94.1%) had high-quality evidence. Results were limited by poor methodology for the development process and incomplete reporting of psychometric properties. Most measures rated "very low" to "low" for quality of measurement properties and none met all quality standards.

Conclusions

This is the first review to synthesise evidence about definitions of response to biologics for severe asthma. While high-quality definitions are available, most are MCIDs or MIDs, which may be insufficient to justify continuation of biologics in terms of cost-effectiveness. There remains an unmet need for universally accepted, patient-centred, composite definitions to aid clinical decision making and comparability of responses to biologics.

Clinical Trial Design Innovations for Precision Medicine in Asthma

Severe asthma is a spectrum disorder with numerous subsets, many of which are defined by clinical history and a general predisposition for T2 inflammation. Most of the approved therapies for severe asthma have required clinical trial designs with population enrichment for exacerbation frequency and/or elevation of blood eosinophils. Moving beyond this framework will require trial designs that increase efficiency for studying nondominant subsets and continue to improve upon biomarker signatures. In addition to reviewing the current literature on biomarker-informed trials for severe asthma, this chapter will also review the advantages of master protocols and adaptive design methods for establishing the efficacy of new interventions in prospectively defined subsets of patients. The incorporation of methods that allow for data collection outside of traditional study visits at academic centers, called remote decentralized trial design, is a growing trend that may increase diversity in study participation and allow for enhanced resiliency during the COVID-19 pandemic. Finally, reaching the goals of precision medicine in asthma will require increased emphasis on effectiveness studies. Recent advances in real-world data utilization from electronic health records are also discussed with a view toward pragmatic trial designs that could also incorporate the evaluation of biomarker signatures.

The Role of Macrophage Autophagy in Asthma: A Novel Therapeutic Strategy

Asthma is a chronic respiratory disease frequently associated with airway inflammation and remodeling. The development of asthma involves various inflammatory phenotypes that impact therapeutic effects, and macrophages are master innate immune cells in the airway that exert diverse functions including phagocytosis, antigen presentation, and pathogen clearance, playing an important role in the pathogeneses of asthma. Recent studies have indicated that autophagy of macrophages affects polarization of phenotype and regulation of inflammation, which implies that regulating autophagy of macrophages may be a potential strategy for the treatment of asthma. Thus, this review summarizes the signaling pathways and effects of macrophage autophagy in asthma, which will provide a tactic for the development of novel targets for the treatment of this disease.

Defining response to therapy with biologics in severe asthma: from global evaluation to super response and remission

INTRODUCTION

In recent years, monoclonal antibodies targeting Type-2 inflammatory pathways have been developed for severe asthma treatment. However, even when patients are carefully selected, the response to treatment varies.

AREAS COVERED

Different studies have evaluated response to therapy with biologics such as exacerbation reduction, symptom improvement, pulmonary function increase, improvement in QoL, or decrease of oral corticosteroids, showing that all patients do not respond to all disease aspects and leading to an extensive debate regarding the definition of response.

EXPERT OPINION

Assessing response to therapy is of great importance, but since there is no uniform definition of treatment response, the recognition of patients who really benefit from these therapies remains an unmet need. In the same context, identifying non-responding patients in which biologic therapy should be switched or substituted by alternative treatment options is of paramount importance. In this review, we present the road trip of the definition of therapeutic response to biologics in severe asthmatics by presenting the current relevant medical literature. We also present the suggested predictors of response, with an emphasis on the so-called super-responders. Finally, we discuss the recent insights regarding asthma remission as a feasible treatment goal and provide a simple algorithm for the evaluation of response.

"Life-changing": the experience of super-responders to biologics in severe asthma

BACKGROUND

There is limited information on the patient's perspective of how biologic treatments impact their lives. We conducted a qualitative study to explore the patient's experience of being considered a super-responder from a quality of life perspective.

METHODS

Patients with severe asthma identified as super-responders were invited to semi-structured interviews conducted online. Participants could bring a family member/friend to the interview. The interviews explored experiences of biologic treatment, were transcribed and underwent thematic analysis.

RESULTS

Twenty-five participants took part in this study. Themes emerged on the impact of biologic treatment for participants and for their friends/family: (i) Words used to describe their often life-changing experiences and (ii) the positive changes noted. Biologic treatment stopped the disruption of family life and social life caused by exacerbations. Improvements in mental health were also noted. Marked individual variations in the way it affected their lives were noted. Most participants noticed improvements 2-3 months after starting their biologic, but some noticed improvement within a few days and others after 6 months.

CONCLUSIONS

Super-responders reported profound but heterogeneous improvements following biologic treatment beyond asthma symptoms and exacerbations including important benefits to social and family life. Improvements may be underestimated as social and family benefits are not reliably measured in current studies with implications for health economic evaluations. Not all patients are super-responders, and excellent responses may be lost in group mean data in trials. Individual time course and response patterns need further elucidation to identify who will respond best to biologics.