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* U.S. filing by end 2016 vs first half 2018 seen previously
* Rivals in triple drug space include AstraZeneca, Novartis (Adds more details on competitive market)
By Ben Hirschler
LONDON, June 2 (Reuters) - GlaxoSmithKline moved toconsolidate its lead in a new class of three-in-one inhaled lungdrugs on Thursday with plans to file its product for U.S.approval by the end of 2016, rather than the first half of 2018as previously expected.
Britain's biggest drugmaker is vying with rivals includingAstraZeneca and Novartis to develop so-called"closed triple" therapies, offering a single inhaler forpatients with chronic obstructive pulmonary disease (COPD).
The idea is to use three different mechanisms of action tohelp open the airways of patients with more severe disease,rather than just two used at present.
Pharmaceutical companies see such inhalers as a significantnew opportunity in a market facing competition from cheapgenerics, although there is debate as to how doctors woulddecide when to step up to or step down from triple therapy.
GSK said it had brought forward its plan to file a New DrugApplication (NDA) in the United States following discussionswith the Food and Drug Administration.
The company, which is market leader in respiratory medicine,was already planning to submit the product for approval inEurope by the end of 2016, but winning a U.S. green light isviewed by analysts as a potentially higher hurdle.
GSK's once-daily drug is being developed with Innoviva and it combines fluticasone, umeclidinium andvilanterol in a single inhaler.
The U.S. drug filing will include clinical trials data nowin hand from the closed triple combination therapy developmentprogramme, as well as data from studies with the componentdrugs, given either alone or in combination.
GSK is suffering from declining sales of its ageing lungtreatment Advair, which already faces generic competition inEurope and could see the arrival of cheap copycats in the UnitedStates next year.
Nonetheless, it predicts its respiratory medicine businesswill grow this year, driven by several new drugs. (Reporting by Ben Hirschler; editing by Jason Neely and JaneMerriman)
