Exploring the feasibility, current use, and efficacy of biomarker based management for the care of patients with asthma

In this thesis by publication we will explore the application of biomarkers and the treatable trait concept in various aspects of the management of patients with asthma. A literature review has been conducted with a focus on the current treatment paradigm of asthma, and the current evidence behind the use of relevant biomarkers. The first publication in this thesis is a case series examining the effects of targeting the treatable trait of eosinophilia in the often understudied population of patients with severe asthma with COPD overlap. In this case series, a treatable trait approach to these patients is seen to be feasible, and demonstrated a positive effect on outcomes including exacerbation rates, lung function, and symptoms. Secondly, a survey on current clinician opinions on the use of biomarkers in Australia will look at the current state of utilization for this concept. The results of this survey highlight the current state of biomarker use in the real world, and particularly, that they are underutilized. Third, a biomarker based strategy will be implemented in non-pharmacologic aspects of the asthma management continuum – in this case, for the assessment of adherence. Using an objective marker of adherence in the form of serum prednisolone levels, this publication has demonstrated the feasibility of this approach to assessing adherence. Last, a randomised controlled trial implementing a biomarker-based algorithm for the management of severe asthma for patients on chronic oral corticosteroids (OCS) will be presented. This study employing a combination of biomarkers in the form of a biomarker score provides further evidence toward the feasibility of a treatable trait approach in this population. The efficacy of this approach is also identified in a trend towards a longer time to severe exacerbation and reduced odds of a hospital admission, and a significantly reduced proportion of patients requiring an emergency visit for their asthma, without a significant difference in the cumulative amount of oral corticosteroids used. To conclude, a discussion about the feasibility and efficacy of this concept for the management of asthma will be undertaken, and future directions briefly explored.