Overall Response to Anti-IL-5/Anti-IL5-Rα Treatment in Severe Asthma Does Not Depend on Initial Bronchodilator Responsiveness.

ABSTRACT

BACKGROUND: Positive bronchodilator responsiveness (BDR) (change in forced expiratory volume in 1 second [ΔFEV1] ≥ +200 mL and ≥ +12%) after inhalation of a short-acting beta-2 agonist has been an inclusion criterion in licensing trials of anti-interleukin 5/anti-interleukin 5 receptor alpha (anti-IL-5/anti-IL-5Rα) biologics in severe asthma. However, in clinical practice, patients with severe uncontrolled asthma frequently show a negative BDR. OBJECTIVE: To investigate whether the response to anti-IL5/anti-IL5Rα therapies differs between patients with positive and negative BDR at baseline. METHODS: Retrospective multicenter analysis of treatment outcomes in patients with severe asthma receiving anti-IL-5/anti-IL-5Rα stratified for baseline BDR. RESULTS: Of 133 patients included, 37 had a positive and 96 had a negative BDR at baseline. Following anti-IL-5/anti-IL-5Rα treatment, FEV1 improved significantly in both groups compared with baseline (P < .0001), with no significant difference between patients with positive and negative BDR (ΔFEV1 +493 mL vs +306 mL; P = .06). Forced vital capacity (FVC) increased (ΔFVC +85 mL vs +650 mL; P < .01) and residual volume (RV) decreased (ΔRV +113 mL vs -307 mL; P < .01) significantly in patients with negative BDR. Median annualized exacerbations (0 vs 0; P = .7), reduction of exacerbation rate (Δexacerbations 0 vs -2; P = .07), continuous oral corticosteroids (OCS) use (Δpatients on OCS -35% vs -39%; P = .99) and improvement of Asthma Control Test (ACT) score (ΔACT 6 vs 5; P = .7) were similar in both groups. Multivariate logistic regression analysis showed no significant correlations of positive versus negative BDR with response parameters. CONCLUSIONS: Both groups improved following treatment with similar responses concerning reduction of OCS therapy, exacerbations, and improvement of symptom control. Pulmonary function also improved in both groups during anti-IL-5/anti-IL-5Rα treatment, with differences in response patterns noted.