UPDATE 1-US panel sees benefit from stronger Advair

(Recasts, adds details and company comment, share price)

By Susan Heavey

WASHINGTON, May 1 (Reuters) - A U.S. advisory panel said GlaxoSmithKline Plc's (GSK.L)(GSK.N) high-dose asthma drug Advair offered a "substantial advantage" for patients with chronic obstructive pulmonary disease, or COPD, despite concerns about infection.

At a meeting on Tuesday to discuss wider use of the drug, the Food and Drug Administration advisers specifically said studies found Advair 500/50 reduced flare-ups of the lung disease but did not help patients live longer.

Advair, which comes in three strengths, is already approved to treat asthma. Only the middle strength -- Advair 250/50 -- is cleared for U.S. patients with COPD, but Glaxo is seeking approval to include its high-dose 500/50 version.

The inhaled drug combines two of Glaxo's other drugs -- Flovent, or fluticasone propionate, and Serevent, or salmeterol

-- to help decrease lung inflammation and relax muscles along -- to help decrease lung inflammation and relax muscles along the airway.

The FDA will make the final decision about whether to support wider use of the 500/50 dose.

While Tuesday's panel said data showed patients experienced fewer bouts of worsening symptoms, they expressed concern about an increased risk of respiratory infections and pneumonia with Advair 500/50 and urged further study.

"The trade off is an increasing risk of pneumonia," said panel member Dr. Marc Moss, another University of Colorado professor.

Panelists said the data was not strong enough to prove the inhaled drug boosted survival.

"I can't see myself saying to a patient, 'Take this drug its going to make you live longer'," said panelist Dr. Lee Newman, a professor at the University of Colorado in Denver.

Some members added it was not clear how doctors would decide between the higher dose and the 250/50 version because Glaxo compared the 500/50 version to a placebo.

Company officials said they were pleased the panelists supported the drug's effect on flare-ups.

Glaxo Vice President Katharine Knobil, who oversees development of respiratory medicines, told Reuters the drugmaker would work with the FDA to decide on final language for the drug's label as well what, if any, studies would need to be done.

A decision is expected by August, Knobil added.

Shares of Europe's biggest drugmaker were down 24 cents, or less than one percent, to $57.54 in late afternoon trade on the New York Stock Exchange.

((Reporting by Susan Heavey, editing by Tim Dobbyn; Reuters Messaging: susan.heavey.reuters.com@reuters.net, Phone: 202-354-5848)) Keywords: GLAXOSMITHKLINE ADVAIR/

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