GlaxoSmithKline hurt by new lung drug data Nonetheless, Glaxo added the totality of the data gave it confidence about the drug's prospects. Therefore, Relovair - a once-daily inhaled medicine - will be filed in Europe and the US in the middle of this year for treating chronic obstructive pulmonary disease (COPD), which covers a variety of conditions affecting the lungs. If all goes well, estimates suggest that sales of Reolvair - which is being developed with US company Therovance - could surpass $1.8bn (£1.2bn) by 2016. Advair, a twice-daily drug, currently generates annual sales of £5bn. While Advair is set to lose patent protection in key markets, it is not yet certain it will face generic competition immediately as respiratory drugs are difficult to copy. It is hoped that the convenience of Relovair's once-daily dosing should appeal to patients and that this will help it carve out a niche alongside Advair. Some in the City were sceptical about Relovair's prospects, however. Mark Clark, an analyst at Deutsche, said the data was "poor" and the failure to beat Advair in clinical outcomes would reduce Relovair's potential and Glaxo's pricing power for the product. Analysts at Barclays Capital also said the results were disappointing, but still expected Relovair to get approved for treating COPD. Darrell Baker, Glaxo's head of respiratory medicine development, said Relovair had reached an important milestone in its development. "Having undertaken an initial assessment of these data we believe they support our plan to seek global approvals... for the treatment of patients with COPD and asthma," he added.