Long-Term Effectiveness of Anti-IL4R Therapy Following Suboptimal Response to Anti-IL5/5R Therapy in Severe Eosinophilic Asthma

Dupilumab is an anti-IL4R monoclonal antibody (mAb) with proven efficacy in severe eosinophilic asthma (SEA). A suboptimal response to anti-IL5/5R mAbs is seen in some patients with ongoing evidence of T2 inflammation. To understand whether targeting IL-13 pathways with dupilumab in these patients may lead to better clinical outcomes. We performed a retrospective analysis of the extended clinical effectiveness of dupilumab up to 2 years of treatment in patients with SEA who had not responded adequately to anti-IL5/5R biologics. Ability to achieve clinical remission and change in the remission domains of exacerbation rate (AER), maintenance oral corticosteroid dose (mOCS), lung function (FEV1) and asthma control (ACQ6) were recorded. Thirty-seven patients (mean age 41, 70% female) were included in the analysis. The mean (SD) AER fell by almost 90% from 3.16(1.28) at dupilumab initiation to 0.35(0.72) after 1 year. The median (IQR) mOCS dose (n=20) fell from 10(5-25) mg to 0 (0-5) mg at 1 year, with 14/20 (70%) able to stop prednisolone altogether. Clinical remission was achieved in 16/37 (43%). Patients who achieved remission had a higher pre-IL5/5R FeNO level (85ppb [39-198] vs 75ppb [42-96], p=0.03). Significant improvements in clinical outcomes are possible following a switch to dupilumab in patients experiencing a suboptimal response to anti-IL5/5R therapies. A higher FeNO in poor responders to anti-IL5/5R who achieve remission with dupilumab is suggestive of an IL-13 driven sub-phenotype of T2-high asthma in which the eosinophil appears unlikely to play a key role in the disease pathogenesis.