AstraZeneca Stops Asthma Drug Study

Low exacerbation rate clouds primary endpoint

Synairgen, a United Kingdom-based respiratory-drug discovery and development company, has received disappointing news from AstraZeneca regarding the inhaled interferon (IFN)-beta product AZD9412, which Synairgen licensed to AstraZeneca in June 2014. AZD9412 acts as an antiviral protein.

The update states: “AstraZeneca has decided to stop the Phase IIa trial for AZD9412 based on an interim analysis, where an overall very low number of reported severe exacerbations could make primary endpoint conclusions difficult.

“The interim analysis confirmed the positive safety and tolerability profile seen in previous trials, and inhaled IFN-beta remains an interesting treatment opportunity for patients with respiratory disease. AstraZeneca will now review the data and study design before deciding on the best way forward for the program.”

AstraZeneca plans to evaluate data from the INEXAS trial with a focus on the study’s secondary endpoints, which are most predictive of asthma worsening to exacerbation. Synairgen has been informed that there will be sufficient numbers of patients in the trial to assess this endpoint. Complete study results are expected in the first quarter of 2017.

In the INEXAS study, asthma patients were treated with AZD9412 or placebo at the onset of common cold symptoms. Previous research has shown that common colds can cause severe asthma exacerbations and that boosting the lung’s antiviral defenses with AZD9412 during this time could prevent exacerbations.

The target number of patients recruited into a clinical trial is based on assumptions about the number of events and the anticipated benefit of the drug. In the INEXAS study, there were fewer exacerbations (events) than anticipated, possibly because of patient selection and environmental/regional factors. Therefore, the primary outcome was difficult to determine within the study’s current design.

Source: Synairgen; October 12, 2016.