Asthma Phenotypes and Endotypes in Uncontrolled Asthma and Eligibility Assessment for Biologics in Severe Asthma Subset: an Indian Perspective

<bold>Background:</bold> Difficult and severe asthma although are a minor proportion of asthma patients they cause significant burden on the health care resources. Guidelines recommend phenotyping, endotyping followed by guideline based assessment for add on therapy in severe asthma. We conducted this study to determine pheno-endotypes of patient with uncontrolled asthma. We also assessed the guideline based eligibility of severe asthma patients for various biologics. <bold>Methods:</bold> Patients diagnosed as uncontrolled asthma were included and were assessed for asthma control. If uncontrolled treatment after optimization they were classified into phenotypes and endotypes based on pre defined characteristics & were assessed for add on biologic therapy. <bold>Results:</bold> 160 patients on moderate or high doses of ICS+LABA and were included in the study. Mean age of study population was 41.09 yrs. The prevalence of difficult asthma, severe asthma and ABPA was 49.04%,12.2 % and 16.47% respectively. Endotyping was done for 160 patients 134 patients (83.75%) had T2 high endotype and 26 patients (16.25%) had T2 low endotype. On assessment for add on therapy 12 patients (37.5%) were eligible for omalizumab, 18 patients (56.25%) were eligible for mepolizumab, benralizumab or dupilumab and 7 patients (21.87%) were eligible for bronchial thermoplasty <bold>Conclusion:</bold>. In our study from a apex centre in urban India, patient identified as severe asthma were 12.2%, thus highlighting the need for a thorough evaluation of all uncontrolled asthma. Amongst severe asthma majority (83.2%) had a T2 high endotype. 20% patients were not eligible for any add on therapy and only 10% could afford it.