Moving Upstream - Anti-TSLP in Persistent Uncontrolled Asthma

Precision medicine in chronic rhinosinusitis - using endotype and endotype-driven therapeutic options

INTRODUCTION

Chronic rhinosinusitis (CRS) is a heterogeneous disease, and its complex pathophysiological characteristics pose a challenge to its clinical treatment. CRS is distinguished not only by clinical phenotype but also by endotype characteristics, which are divided into type 2 CRS and non-type 2 CRS.

AREAS COVERED

In this review, we summarize and discuss current studies that depict the mechanisms and endotypes of CRS. In particular, inflammatory cells and the microbiome play a role in the pathophysiology of CRS. We also listed some of the biomarkers described in recent studies that may serve as a theoretical foundation for additional investigations. We have summarized the advantages and disadvantages of existing treatments and listed the available biological treatments for CRS in detail.

EXPERT OPINION

Endotype-driven therapeutic options face many challenges because of the complexity of the disease. Glucocorticoids, nasal endoscopic surgery, and biological therapy are the main treatments used in clinical practice, but they have limitations. This review provides advice on the clinical management and treatment options for patients with different endotypes, which will be more conducive to improving the quality of life and reducing the financial burden on patients.

Thymic stromal lymphopoietin and alarmins as possible therapeutical targets for asthma

PURPOSE OF REVIEW

Overview of epithelial cytokines, particularly thymic stromal lymphopoietin (TSLP), released by the airway epithelium and the effects of their inhibition on the outcomes of patients with asthma.

RECENT FINDINGS

The epithelial cytokines are early mediators at the top of the inflammatory cascade and are attractive therapeutic targets to prevent exacerbations and improve lung function in patients with type 2 and nontype 2 asthma.

SUMMARY

Clinical trials demonstrated that tezepelumab, an anti-TSLP monoclonal antibody, is a promising alternative treatment for asthma that is effective also in nontype 2 asthma. The PATHWAY and NAVIGATOR trials have assessed its effects in improving outcomes on broad clinically diverse populations. The identification of biomarkers will help to predict potential responders and help in asthma treatment personalization.

The Current State of Biologic Therapies for Treatment of Refractory Asthma

Asthma is a heterogeneous disease, with the immune processes behind the chronic inflammation underlying this disorder differing between the various identified asthma endotypes. In addition to heterogeneity in underlying disease pathophysiology, asthmatics fall across a broad spectrum of disease severity and can vary greatly in their response to convention asthma therapies. A small percentage of patients with severe persistent asthma will remain uncontrolled despite treatment with high-dose inhaled corticosteroids and a long-acting beta-agonist. Less than two decades ago, there were few options for these treatment-refractory asthmatics beyond chronic systemic steroids, with their myriad of treatment-limiting side effects. However, in recent years, there have been a growing number of Food and Drug Administration (FDA)-approved biologic medications with targets that include immunoglobulin E (IgE), interleukin-5 (IL-5), the IL-5 receptor and the IL-4/IL-13 receptor-alpha subunit. The current FDA-approved biologics for severe persistent asthma are omalizumab, mepolizumab, reslizumab, benralizumab, and dupilumab. These monoclonal antibodies have been shown to improve asthma control, decrease asthma exacerbations and decrease glucocorticoid dependence in certain subsets of patients with asthma. The optimal biologic for treatment of severe asthma varies from patient to patient, depending on the underlying pathophysiology of the patient's disease. For each of these medications, there are certain biomarkers that can help predict whether a patient is likely to respond favorably to the medication. This review will discuss the currently approved biologics for severe persistent asthma, including their indications, efficacy and side effects.

New developments in asthma therapeutics

Asthma is a heterogeneous disease characterized by chronic airway inflammation which has been further elucidated over the last 30 years. This has led to a revolution of pharmacologic targets and the recognition of several biomarkers that have allowed for a more personalized approach to asthma. Up to 20% of asthmatics are considered to be refractory despite adequate maintenance inhaled therapy with frequent exacerbations and poor symptom control Vianello et al. (2019). Newly developed therapies targeting cytokines in the asthma inflammatory pathways have led to reduced exacerbations and improved symptom control and lung function in a subgroup of severe asthmatics. Further upstream targets may provide similar improvement for a broader spectrum of asthmatics.

Anti-IL-4/IL-13 for the treatment of asthma: the story so far

Introduction: Severe asthma is a global health concern with high morbidity and mortality. Understanding of its complex pathophysiology continues to increase, providing specific immune targets for therapeutic intervention.Areas covered: In this review, we focus on the role of IL-4 and IL-13 in severe asthma and on the biologic therapies developed to target them, particularly dupilumab, a monoclonal antibody against the IL-4 receptor α subunit and IL-4/IL-13 receptor complex. A literature search was undertaken for all studies of monoclonal antibodies against IL-4 and IL-13.Expert Opinion: Dupilumab decreases the rate of severe asthma exacerbations and improves symptoms, lung function, and quality of life. Importantly, these effects are also observed during reduction of maintenance oral corticosteroid doses. Those with the highest T2 biomarkers derive the greatest benefit and the presence of atopic dermatitis or chronic rhinosinusitis with or without nasal polyposis may recommend dupilumab as the preferred biologic treatment for a patient.

The emergence of new biologics for severe asthma

Patients with severe asthma experience severe symptoms and frequent exacerbations despite intensive treatment with inhaled and oral glucocorticoids. Biologics for severe asthma aim to reduce asthma-related and glucocorticoid-induced morbidity. Recently, new biologics targeting interleukin (IL)-5, IL-5 receptor and IL-4/IL-13, which are all cytokines involved in so-called type 2 airway inflammation, were approved for severe asthma. They show a reduction in exacerbation rate and an oral glucocorticoid-sparing effect. Studies with upstream biologics targeting alarmin cytokines such as thymic stromal lymphopoietin (TSLP) and IL-33 are underway, and newly designed bispecific antibodies targeting more than one pathway are in early phases of development. Such pathway-targeted add-on treatments will soon become standard of care for all patients with severe asthma.

Innate Immunity of the Lung: From Basic Mechanisms to Translational Medicine

The respiratory tract is faced daily with 10,000 L of inhaled air. While the majority of air contains harmless environmental components, the pulmonary immune system also has to cope with harmful microbial or sterile threats and react rapidly to protect the host at this intimate barrier zone. The airways are endowed with a broad armamentarium of cellular and humoral host defense mechanisms, most of which belong to the innate arm of the immune system. The complex interplay between resident and infiltrating immune cells and secreted innate immune proteins shapes the outcome of host-pathogen, host-allergen, and host-particle interactions within the mucosal airway compartment. Here, we summarize and discuss recent findings on pulmonary innate immunity and highlight key pathways relevant for biomarker and therapeutic targeting strategies for acute and chronic diseases of the respiratory tract.