The share price of respiratory disease drug developer Synairgen more than doubled in early trading on Monday after positive developments for its inhaled interferon beta programme.Laboratory experiments confirmed the antiviral potency of IFN-beta against 2009 H1N1, better known as ‘swine flu’.The proportion of lung cells infected by the virus was reduced by 94% over three lab tests when Synairgen’s inhaled IFN-beta treatment was used. This suggests that IFN-beta may have the potential to prevent H1N1-induced respiratory exacerbations of asthma and chronic obstructive pulmonary disease, the company said. ‘This shows how broad an antiviral therapy interferon beta could be,’ claimed Professor Stephen Holgate, co-founder of Synairgen and a non-executive director of the comapany. ‘The key point is that interferon beta acts by protecting the host cells rather than targeting any one incoming specific virus, which is the strategy of other therapies in development,’ Professor Holgate added. More than a quarter of swine flu patients in the USA have been asthmatics and ‘these exacerbation-prone patients need the kind of protection that interferon beta might provide,’ Professor Holgate maintained.