AstraZeneca and Amgen today announced positive results from the NAVIGATOR Phase III trial for the potential new medicine tezepelumab in patients with severe, uncontrolled asthma.

NAVIGATOR met the primary endpoint with tezepelumab added to standard of care (SoC) demonstrating a statistically significant and clinically meaningful reduction in the annualised asthma exacerbation rate (AAER) over 52 weeks in the overall patient population, compared to placebo when added to SoC. SoC was medium- or high-dose inhaled corticosteroids (ICS) plus at least one additional controller medication with or without oral corticosteroids (OCS).

In the subgroup of patients with baseline eosinophil counts less than 300 cells per microlitre the trial also met the primary endpoint, with tezepelumab demonstrating a statistically significant and clinically meaningful reduction in AAER. Similar reductions in AAER were observed in the subgroup of patients with baseline eosinophil counts less than 150 cells per microlitre.

Tezepelumab was very well tolerated in patients with severe asthma. Preliminary analyses show no clinically meaningful differences in safety results between the tezepelumab and placebo groups. Results from the NAVIGATOR trial will be presented at a forthcoming medical meeting.

Severe asthma is a debilitating condition affecting approximately 34 million people worldwide. Many severe asthma patients continue to experience symptoms and frequent exacerbations despite the use of high-dose asthma controller medicines, currently available biologic therapies and OCS.

Professor Andrew Menzies-Gow, Director of the Lung Division, Royal Brompton Hospital, London, UK, and principal investigator of the NAVIGATOR Phase III trial, said: “Due to the complex nature of severe asthma, many patients continue to face debilitating symptoms despite receiving standard of care inhaled medicines and currently approved biologics. Today’s ground-breaking results show that tezepelumab has the potential to transform care for a broad population of severe asthma patients who are underserved today, including those without an eosinophilic phenotype.”

Mene Pangalos, Executive Vice President, BioPharmaceuticals R&D, said: “Tezepelumab works differently from any other asthma biologic medicine and targets multiple inflammatory pathways that contribute to asthma symptoms and exacerbations. Building on the broad efficacy previously seen with tezepelumab, these are exciting data that bring us one step closer to delivering medicine to severe asthma patients, including those with low eosinophil counts.”

Tezepelumab is a potential first-in-class medicine that blocks the action of thymic stromal lymphopoietin (TSLP), an epithelial cytokine that plays a key role across the spectrum of asthma inflammation. NAVIGATOR is the first Phase III trial to show benefit in severe asthma by targeting TSLP.