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

ABSTRACT

Introduction:Dupilumab is an anti-IL4R monoclonal antibody (mAb) with proven efficacy in severe eosinophilic asthma (SEA). We have previously identified that a suboptimal response to the eosinophil targeting anti-IL5/5R mAbs mepolizumab and benralizumab is seen in 27% and 14% of patients with SEA respectively1,2. The mechanism of this is not well-understood. It is unknown whether such patients respond in a clinically meaningful way following a switch to dupilumab. Methods:We performed a retrospective analysis of the clinical effectiveness of dupilumab (minimum 6 months treatment) in patients with SEA at our tertiary severe asthma centre who had failed to adequately respond to at least one of the anti-IL-5/5R mAbs. Change in the annualised exacerbation rate (AER), maintenance oral corticosteroids (mOCS) requirements, ACQ-6 and mAQLQ was recorded. Results:Thirty-two patients (mean age 41.2, 68.8% female, 71.9% atopic) were included in the analysis. 13/32(40.6%) had co-morbid nasal polyposis and 5/32(15.6%) had eczema. The baseline FeNO was 60ppb(IQR 39.6-87.5) and peak eosinophil count prior to any mAb was 0.6(IQR 0.5-0.9). 23/32(71.8%) were switched from benralizumab, of whom, 12/23(52.2%) had also failed to respond to at least one other anti-IL5 mAb previously. At six months, the daily median mOCS dose in those requiring mOCS at baseline (n=18) fell from 10mg(IQR 5-25mg) to 3mg(IQR 0-5mg), p≤0.001. 4/18(22%) were able to stop mOCS completely. Mean(SD) AER improved from 2.34(1.89) to 0.44(0.95), p≤0.001. There were also significant improvements in ACQ6 and mAQLQ that exceeded twice the MCID for both measures: mean (SD) ACQ6 improved from 3.04(1.26) to 1.82(1.28), p≤0.001;mAQLQ improved from 3.90(SD 1.40) to 5.36(SD 1.05), p≤0.001. Due to the COVID-19 pandemic, FEV1 data was only available for 8 patients. However, there was nonetheless a significant rise in FEV1 (%predicted) from 55.6% (9.78) to 68.5%(16.9), p=0.011. One patient discontinued dupilumab during the follow-up period. Conclusion: A minority of individuals with SEA have a suboptimal response to eosinophil targeted therapy with an anti-IL5/5R mAb. In these patients, we report significant clinical improvements following initiation with dupilumab suggesting an important role for the IL-4/-13 pathway in these patients. Further research is required to understand whether these patients represent a distinct subphenotype of T2-high asthma.