ACC: Xience Stent Better than Taxus on Visualized Lumen Loss but Not on Outcomes

March 24, 2007

NEW ORLEANS -- An investigational drug-eluting stent called Xience, coated with everolimus, led to significantly less late lumen loss restenosis after nine months than did the Taxus (paclitaxel-eluting) stent, said researchers here today.

NEW ORLEANS, March 24 -- An investigational drug-eluting stent called Xience, coated with everolimus, led to significantly less late lumen loss after nine months than did the Taxus (paclitaxel-eluting) stent, said researchers here today.

The primary endpoint of the SPIRIT III trial, reported at a late-breaking clinical trial session at the American College of Cardiology meeting, was an angiographic endpoint called in-segment late lumen loss.

By that measure Xience results overpowered Taxus with a 0.14 mm late loss compared with 0.28 mm for Taxus (P

Dr. King commented that "it is difficult to adjudicate ischemia-driven target lesion revascularization when you are using angiography and the 'ocular restenotic effect' -- what you see is what you fix -- takes hold."

The problem, he said, was that the definition of angiographic restenosis-50% stenosis--which he helped develop more than 20 years ago.

He said that the 50% stenosis cutoff was developed in experiments in dogs where the presence of 50% stenosis led to a measurable difference in the flow-rate in a dog's vessels.

Now, however, he realized that a 50% stenosis "had no clinical implication in many patients who remain asymptomatic," which has led him to question the definition he helped to develop. "What does a dog have to do with an 80-year-old human?"

The study enrolled 1,002 patients at 65 U.S. centers. Inclusion criteria included reference vessel diameter of 2.5 mm or more and a lesion length of 28 mm or less with a maximum of two lesions each in a different epicardial vessel.

Six hundred and sixty-nine patients were randomized to Xience and 333 to Taxus. Dr. Stone presented nine-month clinical findings on 657 Xience patients and 321 Taxus patients as well as eight-month angiographic follow-up on 564 patients and eight-month intravascular ultrasound follow-up on 240 patients.

At a press conference, Dr. Stone said the SPIRIT III findings, "meet all FDA regulatory hurdles." Abbott, which has developed the Xience stent, is expected to submit the SPIRIT III data to the FDA by mid-year.

Abbott funded the SPIRIT III trial.