AstraZeneca Plc and Amgen Inc on 26th February jointly announced the phase 3 clinical trial results of the biologic tezepelumab in severe and uncontrolled asthma patients. It demonstrated a clinically meaningful reduction in the annualized asthma exacerbation rate. The experimental drug reduced asthma attacks in patients with severe and uncontrolled forms of the respiratory condition in a large study.
The drug, tezepelumab showed a reduction in the annualised asthma exacerbation rate in severe and uncontrolled asthma patients. Tezepelumab blocks the action of thymic stromal lymphopoietin, an epithelial cytokine that plays a key role across the spectrum of asthma inflammation.
Tezepelumab reduces the rate of asthma attacks by 56 per cent among patients when compared to placebo in a year-long late-stage study, which had roughly 1,000 patients who were already receiving standard care, according to the drugmakers.
These are ground-breaking results for the many patients with severe asthma who continue to face debilitating symptoms despite receiving standard of care inhaled medicines and currently approved biologics, and tezepelumab has the potential to transform treatment for a broad population of patients with severe asthma regardless of their type of inflammation, including those with and without an eosinophilic phenotype, according to the principal investigator of the Navigator phase 3 trial of tezepelumab.
The drug cut the risk of exacerbations by 70 per cent in patients with more than or equal to 300 eosinophils per microlitre of blood, which is the baseline, by 41 per cent in those with less than 300 cells, and 39 per cent with less than 150 cells. Eosinophils are associated with swelling and narrowing of airways that could make asthma attacks worse. The respiratory condition can be triggered and turn severe by many factors, including eosinophil count and allergies.
Tezepelumab works by blocking a type of immune protein called TSLP, found in the linings of the lungs. TSLP belongs to the cytokine group responsible for sounding an alarm to the body's immune system and can also trigger inflammation.
In a press release, Amgen Inc said the NAVIGATOR study results make tezepelumab the first biologic to significantly lower the rate of annualized asthma exacerbation over standard of care regardless of baseline eosinophils, specialized white blood cells that cause inflammation. The lower eosinophil counts are of particular interest for analysts, who have noted that other severe asthma medicines, including Dupixent, are not approved for those patients, and tezepelumab is the only biologic that significantly reduces annualized asthma exacerbation rate in a wide range of severe, uncontrolled asthma patients.