A first-in-class drug under development for severe asthma passed what its developers hope is the final test: achieving its primary endpoint in a phase III registration trial dubbed NAVIGATOR and now reported in a major journal.
Tezepelumab, a monoclonal antibody targeting thymic stromal lymphopoietin (TSLP), cut the annualized rate of asthma exacerbations by more than half relative to the study’s placebo group (rate ratio 0.44, 95% CI 0.37-0.53, P<0.001), according to Andrew Menzies-Gow, MD, of Royal Brompton Hospital in London, and colleagues, writing in the New England Journal of Medicine (NEJM).
Annualized exacerbation rates averaged 0.93 (95% CI 0.80-1.07) in the 528 patients assigned to tezepelumab versus 2.10 for the 532 receiving placebo (95% CI 1.84-2.39) in the 52-week trial.
The drug was superior to placebo for a host of secondary outcomes as well, including forced expiratory volume in 1 second (FEV1), scores on patient-reported assessments of symptom severity and quality of life, and emergency visits and hospitalizations for asthma exacerbations.
If approved, tezepelumab would be the first drug for asthma, or any other condition, targeting TSLP. As Menzies-Gow and colleagues explained, this molecule is a “cytokine implicated in multiple downstream processes involved in asthma pathophysiology.” High levels of it are associated with increased asthma severity and…