Asthma endotypes: the right direction towards personalized medicine for asthma

Therapeutic antibodies: A new era in the treatment of respiratory diseases?

Respiratory diseases affect millions of people worldwide, and account for significant levels of disability and mortality. The treatment of lung cancer and asthma with therapeutic antibodies (Abs) is a breakthrough that opens up new paradigms for the management of respiratory diseases. Antibodies are becoming increasingly important in respiratory medicine; dozens of Abs have received marketing approval, and many more are currently in clinical development. Most of these Abs target asthma, lung cancer and respiratory infections, while very few target chronic obstructive pulmonary disease - one of the most common non-communicable causes of death - and idiopathic pulmonary fibrosis. Here, we review Abs approved for or in clinical development for the treatment of respiratory diseases. We notably highlight their molecular mechanisms, strengths, and likely future trends.

Functional phenotypes determined by fluctuation-based clustering of lung function measurements in healthy and asthmatic cohort participants

RATIONALE

Asthma is characterised by inflammation and reversible airway obstruction. However, these features are not always closely related. Fluctuations of daily lung function contain information on asthma phenotypes, exacerbation risk and response to long-acting β-agonists.

OBJECTIVES

In search of subgroups of asthmatic participants with specific lung functional features, we developed and validated a novel clustering approach to asthma phenotyping, which exploits the information contained within the fluctuating behaviour of twice-daily lung function measurements.

METHODS

Forced expiratory volume during the first second (FEV₁) and peak expiratory flow (PEF) were prospectively measured over 4 weeks in 696 healthy and asthmatic school children (Protection Against Allergy - Study in Rural Environments (PASTURE)/EFRAIM cohort), and over 1 year in 138 asthmatic adults with mild-to-moderate or severe asthma (Pan-European Longitudinal Assessment of Clinical Course and BIOmarkers in Severe Chronic AIRway Disease (BIOAIR) cohort). Using enrichment analysis, we explored whether the method identifies clinically meaningful, distinct clusters of participants with different lung functional fluctuation patterns.

MEASUREMENTS AND MAIN RESULTS

In the PASTURE/EFRAIM dataset, we found four distinct clusters. Two clusters were enriched in children with well-known clinical characteristics of asthma. In cluster 3, children from a farming environment predominated, whereas cluster 4 mainly consisted of healthy controls. About 79% of cluster 3 carried the asthma-risk allele rs7216389 of the 17q21 locus. In the BIOAIR dataset, we found two distinct clusters clearly discriminating between individuals with mild-to-moderate and severe asthma.

CONCLUSIONS

Our method identified dynamic functional asthma and healthy phenotypes, partly independent of atopy and inflammation but related to genetic markers on the 17q21 locus. The method can be used for disease phenotyping and possibly endotyping. It may identify participants with specific functional abnormalities, potentially needing a different therapeutic approach.

Double-stranded RNA evokes exacerbation in a mouse model of corticosteroid refractory asthma

RNA viruses are a major cause of respiratory infections and are known to exacerbate asthma and other respiratory diseases. Our aim was to test the ability of poly(I:C) (polyinosinic:polycytidylic acid), a viral surrogate, to elicit exacerbation in a model of severe asthma driven by HDM (house dust mite) in FCA (Freund's complete adjuvant). Poly(I:C) was administered intranasally around the HDM challenge in FCA-HDM-sensitized animals. Changes in AHR (airway hyperresponsiveness), BALF (bronchoalveolar lavage fluid) inflammatory infiltrate, HDM-specific immunoglobulins and cytokine/chemokine release were evaluated at different points after the challenge. The effect of oral dexamethasone was also assessed. Exacerbation was achieved when poly(I:C) was administered 24 h before the HDM challenge and was characterized by enhanced AHR and an increase in the numbers of neutrophils, macrophages and lymphocytes in the BALF. Th1, Th2 and Th17 cytokines were also elevated at different time points after the challenge. Peribronchial and alveolar inflammation in lung tissue were also augmented. AHR and inflammatory infiltration showed reduced sensitivity to dexamethasone treatment. We have set up a model that mimics key aspects of viral exacerbation in a corticosteroid-refractory asthmatic phenotype which could be used to evaluate new therapies for this condition.

Words matter: distinguishing "personalized medicine" and "biologically personalized therapeutics"

"Personalized medicine" has become a generic term referring to techniques that evaluate either the host or the disease to enhance the likelihood of beneficial patient outcomes from treatment interventions. There is, however, much more to personalization of care than just identifying the biotherapeutic strategy with the highest likelihood of benefit. In its new meaning, "personalized medicine" could overshadow the individually tailored, whole-person care that is at the bedrock of what people need and want when they are ill. Since names and definitional terms set the scope of the discourse, they have the power to define what personalized medicine includes or does not include, thus influencing the scope of the professional purview regarding the delivery of personalized care. Taxonomic accuracy is important in understanding the differences between therapeutic interventions that are distinguishable in their aims, indications, scope, benefits, and risks. In order to restore the due emphasis to the patient and his or her needs, we assert that it is necessary, albeit belated, to deconflate the contemporary term "personalized medicine" by taxonomizing this therapeutic strategy more accurately as "biologically personalized therapeutics" (BPT). The scope of truly personalized medicine and its relationship to biologically personalized therapeutics is described, emphasizing that the best of care must give due recognition and emphasis to both BPT and truly personalized medicine.

Unmet needs in respiratory diseases : "You can't know where you are going until you know where you have been"--Anonymous

The care of patients with respiratory diseases has improved vastly in the past 50 years. In spite of that, there are still massive challenges that have not been resolved. Although the incidence of tuberculosis has decreased in the developed world, it is still a significant public health problem in the rest of the world. There are still over 2 million deaths annually from tuberculosis, with most of these occurring in the developing world. Even with the development of new pharmaceuticals to treat tuberculosis, there is no indication that the disease will be eradicated. Respiratory syncytial virus, severe acute respiratory syndrome, and pertussis are other respiratory infectious diseases with special problems of their own, from vaccine development to vaccine coverage. Asthma, one of the most common chronic diseases in children, still accounts for significant mortality and morbidity, as well as high health care costs worldwide. Even in developed countries such as the USA, there are over 4,000 deaths per year. Severe asthma presents a special problem, but the question is whether there can be one treatment pathway for all patients with severe asthma. Severe asthma is a heterogeneous disease with many phenotypes and endotypes. The gene for cystic fibrosis was discovered over 24 years ago. The promise of gene therapy as a cure for the disease has fizzled out, and while new antimicrobials and other pharmaceuticals promise improved longevity and better quality of life, the average life span of a patient with cystic fibrosis is still at about 35 years. What are the prospects for gene therapy in the twenty-first century? Autoimmune diseases of the lung pose a different set of challenges, including the development of biomarkers to diagnose and monitor the disease and biological modulators to treat the disease.