Synairgen dives after AZ halts asthma trial

Shares in UK biotech Synairgen have dived after AstraZeneca halted a phase 2a trial for its asthma drug, AZD9412, because it had failed to generate efficacy data.

Southampton-based Synairgen licensed AZD9412, inhaled interferon beta, to AZ in June 2014, but has received notification of a setback in clinical development  – all thanks to clinical trial participants catching colds but not seeing their asthma worsen as a result.

AZ has decided to stop the INEXAS clinical trial because data was unexpectedly too weak to show efficacy.

Synairgen and AZ hope to treat asthma by using inhaled interferon beta, an antiviral protein, to boost the antiviral defences of the lung and prevent exacerbations from developing.

But colds in the trial population did not cause as many asthma exacerbations as predicted, making primary endpoint conclusions difficult.

In the trial, asthma patients were dosed with placebo or AZD 9412 at the onset of common cold symptoms.

Previous research had shown common colds can cause severe asthma exacerbations and that boosting antiviral defences of the lung with AZD 9412 could prevent them from developing.

However an interim analysis confirmed the positive safety and tolerability profile seen in previous trials.

Noting that the drug remains an “interesting treatment opportunity” in respiratory disease patients, AZ said it will review data and study design before deciding next steps.

Specifically AZ said it will now focus on secondary endpoint data that predict the disease worsening to exacerbation. There are sufficient numbers of patients in the trial to assess this, and full results are expected in the first quarter of 2017.

Synairgen’s chief executive, Richard Marsden, said: “Although the exacerbation rate in the entire population to date has been lower than we expected based on the assumptions behind the trial design, we look forward to reviewing the other clinically important qualitative and quantitative measures of the potential effectiveness of AZD9412, building on the experience of our previous trial outcomes in this section of the asthmatic population.”

Synairgen had been backed by brokers N+1 Singer and finnCap this year – but shares slumped 13.4% to 20.6p on the London Stock Exchange following the announcement.

Respiratory medicine is one of AstraZeneca’s core therapy areas, and the company is hoping it can launch a new generation of medicines to replace its ageing asthma and COPD portfolio. The firm is expected to file with regulators its new anti-eosinophil monoclonal antibody benralizumab, a treatment for severe asthma, before the end of 2016.


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