AstraZeneca has stopped a phase IIa trial of its AZD9412 drug candidate for asthma after deciding it was unlikely to give conclusive results.
AZD9412 is an inhaled form of interferon beta partnered with UK company Synairgen, which saw its London Stock Exchange-listed shares lose more than a third of their value yesterday when the news was announced. The stock continued to side this morning, losing another 5% by mid-morning.
In a statement, AZ said the decision to stop the INEXAS trial was taken because “an overall very low number of reported severe exacerbations could make primary endpoint conclusions difficult”. The study had been due to report results in February 2017.
AZD9412 was being tested in asthma patients developing symptoms of a cold to see if delivery via a nebuliser could prevent worsening of asthma symptoms that is thought to occur after patients get infected with a respiratory virus.
A defect within lung cells from people with asthma means they do not produce interferon beta themselves, compromising part of the natural host defence against viral infections. The rationale is that delivering with AZD9412 can boost the antiviral defences of the lung during this time and prevent exacerbations from developing.
AZ said it is not giving up on the project just yet as inhaled interferon beta “remains an interesting treatment opportunity for patients with respiratory disease,” but it seems likely that the programme will be delayed by a couple of years even if it chooses to continue.
The company said it will now review the data and study design of INEXAS before taking a decision on a way forward with AZD9412. In particular, it wants to look at secondary endpoints that can be used to predict disease worsening to an acute or subacute asthma attack.
“We hope to learn from the results of this trial which population within severe asthma, or other respiratory diseases, will most benefit from AZD9412 and should be included in future trials,” said Synairgen co-founder Stephen Holgate.
For Synairgen, the setback lends greater importance to its collaboration with Pharmaxis on an oral LOXL2 inhibitor for lung fibrosis that is due to start clinical trials next year, and a second collaboration with AZ looking at the use of AZD9412 in chronic obstructive pulmonary disease (COPD).
AZ licensed the inhaled interferon beta therapy from Synairgen in 2014, paying just over $7m upfront for rights with development and sales milestones raising the potential value of the deal to $232m.