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* GSK drug ahead of similar ones from Teva and AstraZeneca
* Under-the-skin injection set for filing this year
* NEJM editorial questions cost-effectiveness of new drugs
* Analysts see fragmented market for biotech lung treatments (Adds more detail on Teva drug, analyst comment on fragmentedmarket)
By Ben Hirschler
LONDON, Sept 8 (Reuters) - A new group of biotech lung drugsthat have produced promising results in clinical tests are nowup against the issue of how cost-effective that are.
The first is likely to be launched next year byGlaxoSmithKline. Rival firms including TevaPharmaceutical Industries and AstraZeneca areracing to develop similar injectable drugs for patients withsevere asthma, who do not respond adequately to traditionalinhalers.
It is all in pursuit of a new market that analysts believemay be worth around $7.5 billion in annual sales.
But some analysts have estimated the new class of drugsmight cost $10,000 to $15,000 per patient a year.
GSK, the leader in asthma treatments since launching itsVentolin inhaler in 1969, consolidated its position in the newfield by presenting late-stage Phase III data on itsexperimental drug mepolizumab at the European RespiratorySociety congress in Munich on Monday.
The company plans to submit an under-the-skin mepolizumabinjection for regulatory approval before the end of 2014, whileTeva, which also unveiled positive Phase III data in Munich,aims to file its drug reslizumab in the first half of 2015.
AstraZeneca's benralizumab is further behind, although itis seen as a potentially potent competitor.
Other drugs are also in development from several rivalcompanies, suggesting the market for the new treatments maybecome fragmented, according to analysts at Credit Suisse.
GSK had already said in March that mepolizumab reducedserious asthma attacks, known as exacerbations, by around 50percent compared to placebo and cut the need for potentiallydamaging oral steroids, without giving full details.
An editorial in the New England Journal of Medicine (NEJM),where the results were also published, said the data werepromising and the drug's side effects looked acceptable, but itwas unclear how widely it should be used.
Mepolizumab is an anti-interleukin-5 antibody drug thatdepletes a type of white blood cells known as eosinophilsinvolved in lung disorders and is expected to help around halfthe estimated 2 million patients in developed markets withsevere, difficult-to-treat asthma.
Parameswaran Nair, an asthma expert at Canada's McMasterUniversity, said in the NEJM editorial that the data did notsuggest all patients with eosinophil-related severe asthma wouldneed such a treatment, which he expected to be "expensive".
He noted that patients on placebo in one of two studies also had a "remarkable" 50 percent drop in exacerbations, simplyby adhering properly to prescribed conventional therapies, whichwas likely to be more cost-effective.
"This finding would suggest that most patients in thisclinical trial might have had improvement in symptoms withoutmepolizumab simply by the institution of good clinicalpractice," he wrote.
PRICING UNDER WRAPS
GSK, which faces slowing sales of its conventional inhaledlung treatment Advair, said it was premature to talk about pricebut added it planned cost-effectiveness studies to show thevalue of its new product.
"There are currently no options, so we will be the firstinto the marketplace," said Steve Yancy, GSK's developmentleader for mepolizumab.
Xolair, from Novartis and Roche, is theonly biotech asthma drug sold at present, but it works in adifferent way to the new batch of products and is only indicatedfor allergic asthma.
The new class of medicines are also being investigated forthe treatment of chronic obstructive pulmonary disease (COPD),which is linked to smoking.
AstraZeneca earlier reported that benralizumab did notreduce COPD exacerbations in a mid-stage trial, although it diddemonstrate clinically significant improvements in lungfunction. (Editing by Jeremy Gaunt)
