UPDATE 2-New Medtronic stent safe, effective in US trial

Mon Apr 4, 2011 1:14pm EDT

* Target lesion failure rate 3.7 pct vs historical 6.5 pct

* Target lesion revascularization rate 2 percent

* Rate of stent thrombosis .01 percent (Adds background, researcher comment, further data, share price)

By Bill Berkrot and Debra Sherman

NEW ORLEANS, April 4 (Reuters) - Medtronic Inc's (MDT.N) Resolute drug-coated stent met the main safety goals in a large study of U.S. patients, providing the final data the company expects to need to seek U.S. approval of its next generation heart device.

The Resolute stent, designed to release its drug to prevent artery reclogging over a much longer period of time than older models, is already sold in Europe.

In the 1,402-patient study, the rate of target lesion failure -- a composite measure of cardiac death, heart attacks related to the treated blood vessel and need for repeat procedures -- was 3.7 percent after one year. That compares with a historical benchmark from Medtronic's older Endeavor stent of 6.5 percent.

The rate of target lesion revascularization, or need for repeat procedures, was only 2 percent, researchers found.

"These are really low numbers at a year. These results are very strong," Dr. Martin Leon, the study's primary investigator, said, calling the data "as good as we could have hoped for."

There was also an extremely low rate of stent thrombosis, or blood clots forming in the treated vessel. Just two patients suffered stent thrombosis, a rate of .01 percent.

That finding will likely help put to rest some anxiety from an earlier study. While still low in that study, the thrombosis rate was higher than what was seen with Abbott Laboratories' (ABT.N) market-leading Xience stent.

"I think this study pretty effectively should give people a comfort zone that the safety issue is not really a concern," said Leon of the data presented at the American College of Cardiology scientific meeting in New Orleans.

Stents are tiny mesh tubes used to prop open arteries that have been cleared of blockages. They are coated with drugs to help prevent reclogging of the treated vessel.

The U.S. Food and Drug Administration had asked Medtronic for a study specific to U.S. patients to supplement data from an earlier international pivotal trial that showed Resolute to be non-inferior to Abbott's Xience stent.

"You would hope that these data will be the final piece of information that will fill any gaps that the FDA might imagine. It's hard to imagine what more they could want," said Leon, director of the Center for Interventional Vascular Therapy at New York-Presbyterian Hospital/Columbia University Medical Center.

Medtronic, which holds about 12 percent of the U.S. market for drug eluting stents, said it anticipates an FDA approval decision for Resolute in the first half of 2012.

Resolute uses a new polymer believed to be more biocompatible with natural body tissues, thereby making it less prone to polymer-induced thrombosis than those used previously, Medtronic explained.

It is designed to release its drug over 180 days -- far longer than other stents on the market -- which researchers believe will help prevent artery clogging scar tissue from developing later.

"The thought was if you could get more drug out for a little bit longer maybe you could treat difficult patients like diabetics better," Leon explained.

Diabetics represented 34.4 percent of patients in the U.S. Resolute trial, which also tested several sizes of the stents.

Among diabetics the target lesion failure rate was 4.3 percent and the target lesion revascularization rate was 3 percent.

"The results in the diabetic subset were very, very good," Leon said.

Compared to Medtronic's older Endeavor, Leon said Resolute represents "a big leap forward in terms of effectiveness."

He said the next generation stents "appear to be safe, very deliverable, user friendly and very effective."

Medtronic shares were up 6 cents, or 0.2 percent, at $39.56 in afternoon trading on the New York Stock Exchange. (For more on the American College of Cardiology meeting, see [ID:nN03204254] ) (Reporting by Bill Berkrot and Debra Sherman, editing by Dave Zimmerman and Matthew Lewis)