The effectiveness of anti-IL5 biologics is comparable in previous-smokers and never-smokers with severe asthma

Abstract

Background: Anti-IL5/anti-IL5-receptor treatment for severe asthma has demonstrated to be effective in randomized controlled trials. However, such trials do not include patients with a significant smoking history, and little is known about the effectiveness in previous smokers.

Objective: To assess whether previous smoking modifies the effectiveness of anti-IL5/anti-IL5 receptor treatment.

Methods: Patients in the Danish Severe Asthma Register treated with mepolizumab, reslizumab or benralizumab for at least 12 months were included. Percent change in the number of exacerbations and forced expiratory volume in the 1st second of predicted value (FEV1%) and change in mean Asthma Control Questionnaire (ACQ) score from baseline to 12 months were analyzed as continuous variables, adjusting for smoking status, age and sex.

Results: At start of treatment, 132 (44%) were previous smokers with a mean (standard deviation) packyears of 19 (15.6) years and 171 (56%) were never-smokers. After one year of treatment, the number of exacerbations was reduced by 68% (95% confidence interval (CI):55-80) in never-smokers and 54% (43-64) in previous smokers, p=0.10. ACQ score improved with -1.06 (-1.40, -0.72) in previous smokers and -1.03 (-1.37, -0.68) in never-smokers, p=0.91, and FEV1% increased by 13% (7-19) in previous smokers and 11% (4-18) in never-smokers, p=0.63.

Conclusion: In a nationwide cohort of patients with severe asthma, the effectiveness of anti-IL5/anti-Il5 receptor treatment was comparable in previous smokers and never-smokers, suggesting that a significant smoking history does not preclude a clinical effect of biological therapy.