Dupilumab reduces exacerbations independent of changes in biomarkers in moderate-to-severe asthma

BACKGROUND Changes from baseline in fractional exhaled nitric oxide (FeNO) and blood eosinophil count (Eos) may be related to efficacy outcomes in dupilumab-treated patients with moderate-to-severe asthma. OBJECTIVE This post-hoc analysis investigated biomarker changes in placebo- and dupilumab-treated patients with uncontrolled moderate-to-severe asthma enrolled in QUEST (NCT02414854). METHODS Spline analyses of annualized severe exacerbation rate (AER) and change from baseline in pre-bronchodilator (BD) forced expiratory volume in 1 second (FEV1) at Week 52 were performed as a function of fold-change in FeNO at Week 52, and maximum fold-change in Eos over Week 0-12 (also change from baseline in pre-bronchodilator FEV1 at Week 12). RESULTS The combined placebo and dupilumab groups comprised 638 and 1264 patients, respectively. FeNO levels declined rapidly by Week 2 then gradually to Week 52 in patients treated with dupilumab vs placebo; Eos counts, after initially increasing with dupilumab, declined slightly from baseline in both treatment groups. AER during QUEST showed no significant association with change in biomarkers in either treatment group. Change from baseline in pre-bronchodilator FEV1 at Week 52 was inversely associated with fold-change in FeNO in both groups, with significant difference between the dupilumab and placebo curves (P = .014) and was positively associated with fold-change in Eos in both groups (P = .022). CONCLUSION Relative changes in FeNO and Eos were not associated with AER, regardless of treatment arm. However, changes in both biomarkers showed predictive value for lung function improvement; for FeNO this was specific to the dupilumab treatment arm.