Biologic Responders and Super-responders in the International Severe Asthma Registry

Rationale: The efficacy of biologics in severe asthma is well established. However, in real-life some patients respond better than others. This study examined
response and super-response following biologic initiation in patients with severe asthma. Methods: This was a registry-based cohort study based on the
International Severe Asthma Registry (ISAR) including participants from 20 countries which shared data with ISAR between 2017 - 2021. At follow-up the
following criteria defined response in each outcome: improved asthma control, FEV1 improvement ≥100mLs, reduction in annualised exacerbations ≥50%, and
reduced long-term oral corticosteroid (LTOCS) dose. Corresponding super-response cut-offs were: new well-controlled asthma, FEV1 improvement ≥500mLs, no
annualised exacerbations, and LTOCS cessation (or weaning to adrenal insufficiency dosing of (no exacerbations at baseline, well controlled asthma at baseline and/or not on LTOCS at baseline) in each outcome were excluded. Results: A total of 8,451
patients were included, of whom 2,116 initiated and 6,335 did not initiate biologics (anti-IgE, anti-IL5/R, anti-IL4/13) with mean follow up 617 days for those
initiating biologics and 319 days for those who did not. Biologic initiators were younger, more often never-smokers and with earlier asthma onset and worse
baseline asthma status than non-initiators, but there was no difference in asthma biomarkers. Among biologic initiators, symptom control response and superresponse occurred in 49% and 30% of patients, respectively; lung function response and super-response in 54% and 19%; exacerbation response and superresponse in 59% and 27%; and LTOCS response and super-response in 49% and 40% (Table 1). For each outcome, there were more responders and superresponders among patients who initiated biologics than those who did not (pmost patients responded to biologic initiation, but super-response in each outcome was less likely