UPDATE 2-US panel backs new claim for Pfizer lung drug

* FDA advisers back new benefit claim for Spiriva

* Panel says safety data adequate

* Pfizer shares fall 8 cents (Adds panel member, company quotes; updates shares)

By Lisa Richwine

SILVER SPRING, Md., Nov 19 (Reuters) - Pfizer Inc (PFE.N) and Boehringer Ingelheim won support on Thursday for a proposed new claim for a blockbuster medicine that treats a deadly lung disease.

A Food and Drug Administration advisory panel, in an 11-1 vote, said Boehringer presented "substantial and convincing evidence" that Spiriva HandiHaler reduced flare-ups of chronic obstructive pulmonary disease (COPD).

The inhaled medicine already is approved for treating COPD but the companies want to specifically promote it for reducing exacerbations, a claim held by GlaxoSmithKline's (GSK.L) rival drug Advair.

Spiriva is considered the gold standard for treating COPD, or "smoker's lung," commonly caused by cigarette smoke and other harmful fumes and characterized by a persistent obstruction of airflow in the lungs which results in breathlessness.

Two Boehringer studies "showed unequivocal evidence of benefit," said panel member Daren Knoell, an associate professor at Ohio State University's College of Pharmacy.

The FDA usually follows panel recommendations. Winning approval for the new claim could help the company boost sales of the drug, which hit 2.07 billion Euros ($3 billion) globally in 2008.

The FDA advisers also said current data were adequate to address concerns about strokes and heart problems, an issue raised in a medical journal report last year. A team of researchers reported in September 2008 that Spiriva raised the risk of heart attack, stroke and death from heart disease. Boehringer strongly disagreed with the finding.

Members of the FDA panel said there were limitations in the journal study and that other evidence provided reassurance about the drug's safety.

Dr. Mark Brantly, the panel chairman and a pulmonary specialist at the University of Florida, said he felt the overall data "is compelling that there is no increased cardiovascular risk."

The panel voted 11-1 that data were sufficient on the stroke issue, and 11-0 with one abstention that cardiovascular risk data were adequate.

Boehringer said it was pleased the panel supported the claim for reducing disease flare-ups.

"Exacerbations in COPD patients may lead to disability, premature death and increased healthcare costs," Dr. Christopher Corsico, a Boehringer vice president, said in a statement.

Shares of Pfizer, the world's largest drugmaker and Boehringer's marketing partner for Spiriva, fell 8 cents to close at $18.11 on the New York Stock Exchange. (Reporting by Lisa Richwine; Editing by Carol Bishopric)