Liberty Asthma Venture
In this study, the effect of dupilumab on glucocorticoid use among 210 patients with severe asthma was examined. Patients were randomized to add-on dupilumab 300 mg every 2 weeks for 24 weeks. Glucocorticoids were tapered downward from weeks 4 to 20. The primary endpoints were percent reduction in glucocorticoid dose at week 24, and the percentage of patients who experienced a reduction of at least 50% in glucocorticoid dose.
These patients were a mean of 51 years old, with a mean of two severe asthma exacerbations in the past year. Their mean daily oral glucocorticoid dose at randomization was about 11 mg per day. Their mean prebronchodilator FEV1 was about 1.6 liters – about 52% of predicted value.
Oral glucocorticoid use decreased by a mean of 70.1% in the active group, compared with 41.9% in the placebo group, a statistically significant difference, Klaus F. Rabe, MD, of Christian Albrechts University, Kiel, Germany, and his coauthors wrote in the New England Journal of Medicine. The median change was even better: A 100% reduction in the active group and 50% reduction in the placebo group.
By week 24, 80% of those taking dupilumab had decreased their glucocorticoid intake by at least 50%, compared with 50% of the placebo group reaching this goal. The glucocorticoid dose was less than 5 mg/day in 69% of the dupilumab group, compared with 33% of the placebo group.
Like Quest, Venture showed a treatment advantage among patients with high baseline eosinophil count. “The magnitude of the effect was largest in patients with a higher eosinophil count at baseline,” the investigators wrote. “… The odds ratios [a 50% glucocorticoid reduction] for dupilumab versus placebo were 6.59 among patients with 300 or more cells per cubic millimeter at baseline and 2.91 among those with less than 300 cells per cubic millimeter at baseline.”
In a fully adjusted model at week 24, 48% of the patients in the dupilumab group were able to stop oral glucocorticoids entirely, compared with 25% of the placebo group.
Dupilumab was also associated with a significant 59% reduction in severe annual asthma exacerbations. FEV1 among the active group was 0.22 L better than that in the placebo group at week 24.
Again, patients with a higher baseline blood eosinophil count experienced greater treatment benefit; among these, the rate of severe asthma exacerbations was 71% lower than the rate in the placebo group, and FEV1 was 0.32 L higher.
The most frequent adverse events were viral infections (9% of the patients in the dupilumab group vs. 18% of those in the placebo group), bronchitis (7% vs. 6%), sinusitis (7% vs. 4%), influenza (3% vs. 6%), and eosinophilia (14% vs. 1%). Injection-site reactions occurred in 9% of those taking dupilumab and 4% of those taking placebo.
Antidrug antibodies developed in five patients in each group, without clinical effect.
Both trials were funded by Sanofi and Regeneron. Dr. Castro has received grant support from Sanofi. Dr. Rabe has received consulting and lecture fees from AstraZeneca, Boehringer Ingelheim, Novartis, Sanofi, and Teva Pharmaceutical Industries.
SOURCES: Castro M et al. N Engl J Med. 2018;378:2486-96; KF Rabe et al. N Engl J Med. 2018;378:2475-85.