Long-term data presented from the SPIRIT III pivotal US clinical trial demonstrated that the observed clinical advantages of Abbott's market-leading Xience V Everolimus Eluting Coronary Stent System continued to increase as compared to the Taxus Express2 Paclitaxel-Eluting Coronary Stent System (TAXUS).
At three years, Xience V demonstrated a 43 per cent reduction in the risk of major adverse cardiac events (MACE) compared to TAXUS (9.1 per cent for Xience V vs. 15.7 per cent for TAXUS, p-value=0.003). MACE is an important composite clinical measure of safety and efficacy outcomes for patients, defined as cardiac death, heart attack (myocardial infarction or MI), or ischemia-driven target lesion revascularization (ID-TLR driven by lack of blood supply). The three-year results from the SPIRIT III trial was presented by Gregg W Stone, professor of medicine at Columbia University Medical Center, during the 2009 Transcatheter Cardiovascular Therapeutics (TCT) conference in San Francisco.
"The SPIRIT III results clearly demonstrate that at three years, patients continue to benefit from having been treated with the Xience V stent rather than the TAXUS stent, with fewer repeat cardiac procedures and fewer heart attacks in patients who received Xience V," said Dr Stone, who is also immediate past chairman of the Cardiovascular Research Foundation, New York; and principal investigator of the SPIRIT III trial.
Xience V demonstrated an impressive low rate of very late stent thrombosis (one to three years) with no additional events between two and three years. Per protocol, Xience V demonstrated a 0.2 per cent very late stent thrombosis rate compared to 1.0 per cent for TAXUS (p-value=0.10) at three years. Per Academic Research Consortium (ARC) definition of definite/probable stent thrombosis, the rate of very late stent thrombosis at three years was 0.3 per cent for Xience V and 1.0 percent for TAXUS (p-value=0.34). The ARC definitions of stent thrombosis were developed to eliminate variability in the definitions across various drug eluting stent trials.
"The SPIRIT III data clearly show that Xience V performs in a consistent manner, with clinical benefits continuing to improve over time compared to TAXUS," said Robert Hance, senior vice president, vascular, Abbott. "We are pleased to begin this year's TCT conference with a strong showing of data for Abbott's market-leading Xience V, and look forward to presenting the highly anticipated SPIRIT IV one-year results later this week, which should provide physicians with additional valuable insights."
One-year results from the company's SPIRIT IV trial will be presented on Wednesday, Sept. 23, during the first late-breaking clinical trials session of the TCT conference. The SPIRIT IV trial is one of the largest randomized clinical trials between two drug eluting stents, with 3,690 patients enrolled, including more than 1,000 patients with diabetes. The study results will provide valuable information about the efficacy and safety of Xience V compared to TAXUS. The SPIRIT III trial was not designed to analyze statistical differences in any of the patient subgroups, as the sample sizes were too small to draw firm conclusions.
Xience V is used to treat coronary artery disease by propping open a narrowed or blocked artery and releasing the drug, everolimus, in a controlled manner to prevent the artery from becoming blocked again following a stent procedure.