Abbott Xience stent outperforms rival

Abbott Laboratories' drug-coated Xience V stent prevented heart attacks and repeat surgeries more than an older artery-opening device from Boston Scientific, a study found.

After a year, 4.2 percent of patients who got Xience had complications, compared with 6.8 of those who got Boston Scientific's Taxus Express, according to an Abbott-funded study presented today at a medical meeting.

The results may help Xience, cleared for U.S. sale last year, steal market share from Taxus, available since 2004. Xience, and a version of the device called Promus sold by Boston Scientific, are currently used in 54 percent of U.S. procedures to implant the drug-coated stents, said Michael Weinstein, a JPMorgan Chase & Co. analyst, in a Sept. 21 note to clients.

"Xience and Promus have half the global market already; the vote is in," said Rick Wise, an analyst with Leerink Swann in New York, in a phone interview before the data was released. Positive results will help Xience gain even more share, he said.

Boston Scientific will stop selling Taxus Express worldwide next week, said Keith Dawkins, the company's associate chief medical officer, in a phone interview today. The company, based in Natick, Massachusetts, will instead promote a newer model, Taxus Liberte, approved for U.S. sale in October 2008, he said.

"We obviously would have preferred a comparison with Liberte," Dawkins said.

Abbott fell 37 cents to $46.36 at 2:07 p.m. in New York Stock Exchange composite training. Boston Scientific fell 5 cents to $10.94.

Chemical Polymer

Stents are tiny metal mesh tubes that keep arteries open after doctors clear clogged vessels in a procedure called a balloon angioplasty. Newer devices are coated with a chemical polymer and drugs to prevent the growth of tissue re-blocking the artery, the main complication of older bare-metal models.

Today's study was presented at the Transcatheter Cardiovascular Therapeutics meeting in San Francisco.

The trial followed 3,690 patients with coronary artery disease for one year after they had one or more stents inserted in the arteries leading to their heart.

Among patients with the Xience stent, 2.5 percent needed an additional procedure to clear the stented artery, compared with 4.6 percent of people outfitted with the Taxus stent. Among Xience patients, 1.8 percent had heart attacks, compared with 2.9 percent of the Taxus patients.

The risk of deaths from a heart attack was the same with each device, occurring in 0.4 percent of patients, the study found.

Doctors prefer using the newer stents because they're easier to thread into patients' arteries and today's results will help them feel more confident in their preference, said Sunil Rao, a cardiologist at Duke University Medical Center in Durham, North Carolina. Rao said he doesn't accept fees from either device maker.

'Flexible, Easier'

"We had a hard time placing the older stents and they weren't very flexible," Rao said in a telephone interview yesterday. "It's nice that they're coming out with data that say that not only are the newer ones easier to use but they're better than the older generation too."

The Xience stent is coated with a polymer that contains the cancer drug everolimus, while older stents, including the Taxus Express, contain a different cancer drug, paclitaxel. Both drugs are used to prevent new blood clots from forming around the stent.

The two stents differ in ways beyond the drugs they each contain, said Gregg Stone, a Columbia University cardiologist who led the study released today, called Spirit IV.

The Xience stent is more flexible with thinner, more malleable struts, Stone said in a Sept. 21 telephone interview. The polymers that coat the Xience stent and hold the drug are thinner and seem to cause less inflammation than those used in the Taxus stent, he said.

'Safety and Efficacy'

"When the Xience V stent was developed, the specific design goals were to look at each of those three components and to optimize the safety and efficacy of each one," Stone said. "That seems to have been accomplished."

Xience accounted for most of the $800 million Abbott brought in from coronary stent sales in the first half of 2009, said Abbott spokesman Jonathon Hamilton. The company is based in Abbott Park, Illinois.

Abbott obtained Xience when it purchased Guidant Corp.'s stent business for $4.1 billion in April 2006.

Taxus stents made up $1.32 billion of Boston Scientific's 2008 sales, according to a company filing with the U.S. Securities and Exchange Commission.