FDA warns on Boston Scientific aortic stent trial

(Adds detail, background, byline)

By Debra Sherman

CHICAGO, Sept 7 (Reuters) - U.S. health regulators charged Boston Scientific Corp (BSX.N) with inadequate record-keeping and reporting following the deaths of five patients implanted with an experimental device to treat a dangerous ballooning of the body's main artery.

The Aug. 30 warning letter from the U.S. Food and Drug Administration is another blow to Boston Scientific, which is operating under a 2006 FDA warning letter related to quality management and other problems, as it struggles with shrinking markets.

The company has until mid-September to address the FDA's concerns and provide documentation on two U.S. trials: an early stage trial that involved 43 patients and a mid-stage trial that did not involve the implantation of the device known as a stent graft.

The stent graft was designed to treat abdominal aortic aneurysms, or AAA, which affects as many as 8 percent of people over the age of 65, accounting for more than 15,000 deaths in the United States each year.

The clinical trials started in 2003 and ended in 2006, after Boston Scientific became aware of fractures in the device and scrapped the program.

"Two of these deaths had not been evaluated to determine if there was a relationship between the deaths and the investigational device or to determine if they would be considered to be an (adverse event)," according to a copy of the letter obtained by Reuters.

There was no evidence that any follow-up information was requested or obtained from the clinical trial sites after the deaths, the FDA letter said. The regulator also cited Boston Scientific for failing to report so-called adverse events, which include death and injuries, in the trial.

It characterized Boston Scientific's previous responses as "inadequate."

Doctors implant the stent graft, a tubular device made of fabric and metal, through incisions in the groin. It is then threaded through a vessel inside a catheter until it reaches the aorta, the main blood-carrying vessel. The device is then placed over the aorta and sewn in place to reinforce the life-threatening bulge.

"We have no evidence indicating any of the deaths were related to the stent graft fractures," Boston Scientific spokesman Paul Donovan said.

Boston Scientific acquired the stent through the purchase of TriVascular Inc. in April 2005.

Some Wall Street analysts expect the company to unload TriVascular Inc. as part of a larger effort to divest non-core businesses in order to pay down debt from its acquisition of Guidant last year.

Boston Scientific shares closed 2 cents lower at $13.21 on the New York Stock Exchange.

((Editing by Leslie Gevirtz; Reuters Messaging: debra.sherman.reuters.com@reuters.net; debra. sherman@reuters.com, 1-312-408-8134)) Keywords: BOSTONSCIENTIFIC WARNING/

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