Exploring Definitions and Predictors of Severe Asthma Clinical Remission after Biologic Treatment in Adults.

Rationale: There is no consensus on criteria to include in an asthma remission definition in real life. Factors associated with achieving remission after biologic initiation remain poorly understood. Objectives: To quantify the proportion of adults with severe asthma achieving multidomain-defined remission after biologic initiation and identify prebiologic characteristics associated with achieving remission that may be used to predict it. Methods: This was a longitudinal cohort study using data from 23 countries from the International Severe Asthma Registry. Four asthma outcome domains were assessed in the 1 year before and after biologic initiation. A priori-defined remission cutoffs were: 0 exacerbations/yr, no long-term oral corticosteroid (LTOCS), partly/well-controlled asthma, and percent predicted FEV1 ⩾ 80%. Remission was defined using two (exacerbations + LTOCS), three (+control or +lung function), and four of these domains. The association between prebiologic characteristics and postbiologic remission was assessed by multivariable analysis. Measurements and Main Results: A total of 50.2%, 33.5%, 25.8%, and 20.3% of patients met criteria for two-, three- (+control), three- (+lung function), and four-domain remission, respectively. The odds of achieving four-domain remission decreased by 15% for every additional 10 years of asthma duration (odds ratio, 0.85; 95% confidence interval, 0.73-1.00). The odds of remission increased in those with fewer exacerbations per year, lower LTOCS daily dose, better control, and better lung function before biologic initiation. Conclusions: One in five patients achieved four-domain remission within 1 year of biologic initiation. Patients with less severe impairment and shorter asthma duration at initiation had a greater chance of achieving remission after biologic treatment, indicating that biologic treatment should not be delayed if remission is the goal.

Exploring Definitions and Predictors of Response to Biologics for Severe Asthma.

BACKGROUND: Biologic effectiveness is often assessed as response, a term that eludes consistent definition. Identifying those most likely to respond in real-life has proven challenging. OBJECTIVE: To explore definitions of biologic responders in adults with severe asthma and investigate patient characteristics associated with biologic response. METHODS: This was a longitudinal cohort study using data from 21 countries, which shared data with the International Severe Asthma Registry. Changes in four asthma outcome domains were assessed in the 1-year period before and after biologic initiation in patients with a predefined level of prebiologic impairment. Responder cutoffs were 50% or greater reduction in exacerbation rate, 50% or greater reduction in long-term oral corticosteroid daily dose, improvement in one or more category in asthma control, and 100 mL or greater improvement in FEV1. Responders were defined using single and multiple domains. The association between prebiologic characteristics and postbiologic initiation response was examined by multivariable analysis. RESULTS: A total of 2,210 patients were included. Responder rate ranged from 80.7% (n = 566 of 701) for exacerbation response to 10.6% (n = 9 of 85) for a four-domain response. Many responders still exhibited significant impairment after biologic initiation: 46.7% (n = 206 of 441) of asthma control responders with uncontrolled asthma before the biologic still had incompletely controlled disease postbiologic initiation. Predictors of response were outcome-dependent. Lung function responders were more likely to have higher prebiologic FeNO (odds ratio = 1.20 for every 25-parts per billion increase), and shorter asthma duration (odds ratio = 0.81 for every 10-year increase in duration). Higher blood eosinophil count and the presence of type 2-related comorbidities were positively associated with higher odds of meeting long-term oral corticosteroid, control, and lung function responder criteria. CONCLUSIONS: Our findings underscore the multimodal nature of response, showing that many responders experience residual symptoms after biologic initiation and that predictors of response vary according to the outcome assessed.