Abbott touts safety of Xience stent in diabetics, eyes Boston Scientific market share

Abbott highlights stent results in diabetics

WASHINGTON — Abbott Laboratories says results of a large study place its artery-opening Xience stent on equal footing with competitor Boston Scientific in diabetics, a difficult-to-treat group of patients.

The company announced Wednesday there was no difference in safety complications after one year between diabetic patients with a Xience drug-coated stent, versus Boston Scientific’s Taxus Express stent.

The combined rate of heart attack, death and other adverse events was 6.4 percent for Xience and 6.9 percent for Taxus, the company said. The difference was not statistically significant.

Previous results had suggested fewer heart-related problems with Taxus, helping Boston Scientific protect its share of the market for the tiny, mesh-wire tubes.

For its part, Boston Scientific said Abbott compared Xience to Taxus Express, a stent which has been largely replaced by the newer Taxus Liberte model, which launched last year.

“This is not comparing apples to apples, it’s comparing apples to oranges,” said Dr. Keith Dawkins, senior vice president with Boston Scientific.

The Natick, Mass.-based company said Wednesday it will begin phasing out Taxus Express next week.

Another study presented Wednesday showed superior results for Xience even when compared to the newer Taxus Liberte stent. The 1,800-patient study recorded a 6.2 percent rate of complications for Xience, compared with 9.1 percent for Taxus. The study was conducted at a single hospital in the Netherlands and was not considered as comprehensive as the Abbott study, which involved multiple sites in different countries.

Stents are used to prop open arteries after they have been surgically cleared of fatty plaque. They became one of the top-selling medical devices ever after companies began adding drug coatings in 2003 to prevent scar tissue from growing over the mesh.

But sales have declined from a high point of $3.1 billion in 2005 over safety concerns that they may cause more blood clots than older, bare-metal stents. More recent studies have suggested the risks of drug-coated stents are on par with regular stents.

Xience has already shown significantly fewer problems in non-diabetics, and those results continued with 38 percent fewer adverse events for Xience compared with Taxus.

Dr. Gregg Stone said the neutral results in diabetics combined with superior results for regular patients make Xience a safer option.

“I think most people who look at this data are going to see that the Xience V stent is safer in general,” said Stone, a Columbia University cardiologist who serves as a paid adviser to both Abbott and Boston Scientific.

Stone noted that the study included more than 3,600 patients, making it the largest head-to-head comparison of drug-coated stents ever conducted.

Abbott Executive Vice President John Capek said the large number of diabetics in the study — over 1,000 — give the results added weight for predicting safety in that group.

“What’s been a challenge in all the drug-eluting trials to date has been the number of diabetic patients hasn’t been large enough to come to a conclusion regarding the performance of one technology versus another,” said Capek.

North Chicago-based Abbott released the results at the annual Transcatheter Cardiovascular Therapeutics conference in San Francisco, a meeting for interventional cardiologists.

About 25 percent of patients who receive a stent have diabetes, which puts them at increased risk for stent complications.

“Patients with diabetes tend to have smaller vessels with longer lesions and they form more scar tissue inside the stent,” said Stone.

JP Morgan analyst Michael Weinstein wrote ahead of the meeting that positive results in diabetics for Abbott could “lead to a downturn in Taxus share and renewed momentum for Xience and Promus.”

Promus is a version of Xience which Boston Scientific licenses from Abbott, which collects 40 percent of the revenue on sales of the product.

When Promus is included, Boston Scientific controls about 46 percent of the U.S. market for drug-coated stents, according to figures from Wells Fargo analyst Larry Biegelsen.

Abbott’s Xience has quickly snatched up 51 percent of the market since its launch last summer.

Other competitors in the stent space are Johnson & Johnson and Medtronic.

Shares of Abbott Laboratories fell 60 cents to close at $46.13. Boston Scientific shares fell 17 cents to close at $10.82.