Clinical response to biologic therapies in patients with severe asthma: impact of obesity status

Background Biologic agents targeting airway inflammation improve symptoms and reduce corticosteroid use in severe asthma. Obesity is associated with more severe disease and greater corticosteroid dependence. However, data are limited on whether obesity modifies the clinical response to biologics.Objective To compare clinical outcomes of biologics in severe asthma patients with and without comorbid obesity.Methods We conducted a retrospective, single-center observational study of adults with severe asthma receiving biologics. Patients were classified by obesity status (BMI > 30 kg/m2). Baseline characteristics and outcomes at 6 months were compared, including proportion of patients experiencing at least one exacerbation, changes in weight and lung function, and biologic switching/discontinuation.Results Eighty-one patients were included (mean age 58 ± 17 years; mean BMI 28.1 ± 7.7 kg/m2), of whom 28 (34.5%) were obese. Obese patients had higher prevalence of obstructive sleep apnea (25% vs. 3.8%, p < 0.001) and more often received triple inhaled therapy (85.7% vs. 54.7%, p = 0.005). Baseline proportion of patients experiencing at least one exacerbation were similar between obese and non-obese patients (median 3 [IQR 1–3] vs. 2 [1–3], respectively; p = 0.356). At 6 months, the proportion of patients with at least one exacerbation was 28.6% in obese patients (8/28) and 20.8% in non-obese patients (11/53), with no significant difference between groups (OR 1.53, 95% CI 0.53–4.39; p = 0.431). Obese patients experienced modest but significant weight loss (p = 0.045). Biologic switching/discontinuation rates were similar.Conclusions Obesity did not significantly alter the clinical response to biologics in severe asthma, suggesting comparable efficacy across BMI categories.Further studies with deeper phenotyping are needed to optimize treatment strategies for this complex phenotype.