BACKGROUND: Dupilumab is a fully human anti-interleukin-4 receptor α monoclonal 
antibody that blocks both interleukin-4 and interleukin-13 signaling. We 
assessed its efficacy and safety in patients with uncontrolled asthma.
METHODS: We randomly assigned 1902 patients 12 years of age or older with 
uncontrolled asthma in a 2:2:1:1 ratio to receive add-on subcutaneous dupilumab 
at a dose of 200 or 300 mg every 2 weeks or matched-volume placebos for 52 
weeks. The primary end points were the annualized rate of severe asthma 
exacerbations and the absolute change from baseline to week 12 in the forced 
expiratory volume in 1 second (FEV1) before bronchodilator use in the overall 
trial population. Secondary end points included the exacerbation rate and FEV1 
in patients with a blood eosinophil count of 300 or more per cubic millimeter. 
Asthma control and dupilumab safety were also assessed.
RESULTS: The annualized rate of severe asthma exacerbations was 0.46 (95% 
confidence interval [CI], 0.39 to 0.53) among patients assigned to 200 mg of 
dupilumab every 2 weeks and 0.87 (95% CI, 0.72 to 1.05) among those assigned to 
a matched placebo, for a 47.7% lower rate with dupilumab than with placebo 
(P<0.001); similar results were seen with the dupilumab dose of 300 mg every 2 
weeks. At week 12, the FEV1 had increased by 0.32 liters in patients assigned to 
the lower dose of dupilumab (difference vs. matched placebo, 0.14 liters; 
P<0.001); similar results were seen with the higher dose. Among patients with a 
blood eosinophil count of 300 or more per cubic millimeter, the annualized rate 
of severe asthma exacerbations was 0.37 (95% CI, 0.29 to 0.48) among those 
receiving lower-dose dupilumab and 1.08 (95% CI, 0.85 to 1.38) among those 
receiving a matched placebo (65.8% lower rate with dupilumab than with placebo; 
95% CI, 52.0 to 75.6); similar results were observed with the higher dose. Blood 
eosinophilia occurred after the start of the intervention in 52 patients (4.1%) 
who received dupilumab as compared with 4 patients (0.6%) who received placebo.
CONCLUSIONS: In this trial, patients who received dupilumab had significantly 
lower rates of severe asthma exacerbation than those who received placebo, as 
well as better lung function and asthma control. Greater benefits were seen in 
patients with higher baseline levels of eosinophils. Hypereosinophilia was 
observed in some patients. (Funded by Sanofi and Regeneron Pharmaceuticals; 
LIBERTY ASTHMA QUEST ClinicalTrials.gov number, NCT02414854 .).