Amgen and AstraZeneca announced that the Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation for tezepelumab in patients with severe asthma without an eosinophilic phenotype.
Tezepelumab is a potential first-in-class medication that works by blocking thymic stromal lymphopoietin (TSLP), an epithelial cytokine that is involved in the initiation and persistence of airway inflammation. Inhibition of TSLP is thought to prevent the release of pro-inflammatory cytokines by immune cells resulting in the prevention of asthma exacerbations and improved asthma control. Biologic therapies currently on the market only target type 2 driven inflammation.
The designation was based on data from the Phase 2b PATHWAY trial that evaluated 3 doses of tezepelumab as add-on therapy in patients with a history of asthma exacerbations and uncontrolled asthma receiving inhaled corticosteroids/long-acting β-agonist with or without oral corticosteroids and additional asthma controllers vs placebo.
Data showed that treatment with tezepelumab led to significant reductions (62% [70mg every 4 weeks], 71% [210mg every 4 weeks], and 66% [280mg every 2 weeks]) in the annual asthma exacerbation rate vs placebo (P <.001 for all) in patients with severe asthma. This effect was seen regardless of baseline blood eosinophil count or other type 2 inflammatory biomarkers. Asthma-related effects, nasopharyngitis, headaches, and bronchitis were the most common adverse events associated with tezepelumab.
Tezepelumab is being investigated in the Phase 3 PATHFINDER clinical program, which includes planned mechanistic and long-term safety trials.