P86 Does adherence to ICS/LABA therapy change following initiation of Benralizumab in the treatment of severe asthma and does this affect outcome?

Introduction and objectives Benralizumab is used in severe eosinophilic asthma (SEA), in addition to other optimised therapies, to improve disease control and reduce exacerbation frequency. It is unknown if SEA patients alter their usage of inhaled therapies, including inhaled corticosteroids (ICS) and short acting B-agonists (SABA), following initiation of Benralizumab. We have previously reported an increased risk of exacerbations in Mepolizumab patients who are poorly adherent to maintenance ICS, but it is unknown if a reduction in ICS adherence alters clinical outcomes whilst on Benralizumab. Methods We assessed SEA patients who had completed at least 24 weeks of Benralizumab therapy, and measured if inhaler use changed before and after its initiation. We also investigated whether a reduction in ICS use affected outcomes. Adherence, expressed as the Medicines Possession Ratio (MPR), was calculated from primary care prescription records. The MPR is a ratio of the number of doses issued on prescription/number that would be expected to be used. Good adherence was defined as a usage ratio >0.8, poor adherence was an MPR Results The adherence of 83 patients receiving Benralizumab was assessed. 59% were female, age 51.8±13.9 years, 47% had adult onset disease, 75% were atopic and 60% were receiving maintenance oral corticosteroids (OCS). Whilst on Benralizumab, the overall ICS-containing annualised MPR reduced from 0.92±0.42 to 0.81±0.36 (p=0.063). A reduction was seen in the absolute numbers of both ICS inhalers (11.0±5.1 vs 8.8±3.9; p=0.002) and SABA inhalers (14.3±13.3 vs 9.9±10.1; p=0.001) collected, equivalent to an average reduction from 7.8 doses of salbutamol/day before Benralizumab to 5.4 doses/day after. Post-initiation of Benralizumab, 20 patients (24.1%) had poor adherence to ICS. There was no difference in baseline MPR between those with subsequent poor and good ICS adherence (0.91±0.53 vs 0.96±0.38; p=0.71), and no significant differences at 24 weeks in changes in FeNO level, lung function, ACQ scores, OCS dose or exacerbation frequency. See table 1. Conclusions Usage of ICS and SABA decreased on Benralizumab therapy, and previous adherence was not a predictor of on-treatment adherence. This diminished ICS use was not associated with a significant difference in the number of exacerbations or other outcome measures.