Mepolizumab and Benralizumab are anti IL 5/ IL5 R antibodies that are licensed for the treatment of eosinophilic asthma in the UK. Airway hyper-responsiveness and eosinophil recruitment is part of the pathogenesis of asthma and targeting interleukin-5 can inhibit this. Biologics have been used for asthma that does not respond adequately to standard therapy to reduce the oral corticosteroid burden and lessen the associated side effects. These agents are initiated in selected centres in the UK after a severe asthma MDT discussion. For mepolizumab and benralizumab patients need a eosinophil count of at least 300 or 400 cells per microlitre and 4 or 3 exacerbations requiring systemic corticosteroids in the last 12 months  respectively. 

To see whether anti-IL5 inhibitors did significantly reduce oral corticosteroid burden we performed a retrospective cohort study on 80 patients who were given mepolizumab or benralizumab and compared at one year follow up the oral corticosteroid burden and whether it had reduced by at least 50%, exacerbation rates, ACT, exhaled nitric oxide, eosinophil counts and FEV1 versus before initiation of a biologic. We excluded deceased patients and those who had not had their 1 year follow up by December 2022 leading to a final study population of 57 patients. 

Of the 57 patients, 46 were deemed to be responders to the biologic but only 15 managed to reduce their oral corticosteroid burden by 50%. This was significant statistically. As a result of the severe restrictions during the pandemic there were some absent data relating to the follow-up of these patients at 12 months. We present these real life findings.