Abbott announced that data presented from its Spirit III US pivotal clinical trial demonstrated continued positive, statistically significant clinical results for the Xience V Everolimus Eluting Coronary Stent System at one year, including continued clinical superiority in major adverse cardiac events (MACE) and continued non-inferior rates of target vessel failure (TVF) with Xience V compared to the Taxus Paclitaxel-Eluting Coronary Stent System.
The results were presented at the Cardiovascular Research Foundation's 19th annual Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium in Washington D.C. These results follow the data presented earlier this year at the annual American College of Cardiology conference, wherein Xience V demonstrated superiority to Taxus in the Spirit III trial on the study's primary endpoint of in-segment late loss at eight months with a statistically significant 50 per cent reduction in late loss compared to Taxus. (In-segment late loss is a measure of vessel renarrowing). The Spirit III clinical trial of 1,002 patients demonstrated the following key results for Xience V at one year:
In an analysis of major adverse cardiac events (MACE), Xience V demonstrated clinical superiority to Taxus with a statistically significant 43 per cent reduction in MACE compared to Taxus at one year. These MACE results are consistent with the clinically superior 44 per cent reduction in MACE observed for Xience V at nine months. MACE is an important 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 (TLR driven by lack of blood supply).
In the major secondary endpoint of Target Vessel Failure (TVF), Xience V continued to demonstrate statistical non-inferiority to Taxus with an observed 23 per cent reduction in Target Vessel Failure for Xience V compared to Taxus (8.3 per cent Xience V, 10.8 per cent Taxus) at one year. Target Vessel Failure is a measure of re-treatment anywhere within the target vessel and includes cardiac death or heart attack.
There was no evidence of a difference in either acute (30 day) or late thrombosis rates between Xience V and Taxus out to one year.
"To date, Xience V is the only drug-eluting stent system that has demonstrated a statistically significant improvement in event-free survival compared to another FDA approved drug-eluting stent in a pivotal randomized clinical trial. In Spirit III, the risk for patients on the important clinical endpoint of MACE - cardiac death, heart attack or retreatment in the diseased artery area - was approximately 43 per cent lower with Xience V than Taxus at 1 year. A reduction in MACE with Xience V compared to Taxus was also present at 1 year in the smaller Spirit II trial, demonstrating that this is a robust, reproducible difference," said Gregg W. Stone, M.D., Columbia University Medical Center and the Cardiovascular Research Foundation, New York, principal investigator of the Spirit III clinical trial.
There was no evidence of a statistical difference between rates of stent thrombosis for Xience V or Taxus out to one year in the SPIRIT III trial. Rates of late stent thrombosis at one year per protocol were 0.3 per cent for Xience V and 0.6 per cent for Taxus. Rates of definite/probable late stent thrombosis at one year under ARC definition were 0.5 per cent for Xience V and 0.6 per cent for Taxus.
A variety of Spirit III subgroup analyses showed additional observational evidence of favorable clinical and angiographic results for Xience V; however, the trial was not designed to analyze statistical differences in any of the sub-groups, including diabetic patients.
"The results from Xience V represent an important advancement for patients with coronary artery disease," said John M. Capek, Ph.D., executive vice president, Medical Devices, Abbott. "As a next generation drug eluting stent, Xience V continues to demonstrate longer-term safety and consistently superior efficacy results across the Spirit trials with the potential to raise the bar for all DES."
The Xience V system utilizes everolimus, which has been shown to reduce tissue proliferation in the coronary vessels following stent implantation, and is based upon the highly deliverable and proven Multi-Link Vision coronary stent platform.
Xience V was launched in Europe and Asia Pacific in 2006. Xience V is currently an investigational device in the United States and Japan. Results from the Spirit III trial are intended to support US Food and Drug Administration (FDA) approval of the Xience V Stent System and Ministry of Health and Welfare approval in Japan. Abbott anticipates receiving Xience V US FDA approval in the first half of 2008.
Abbott supplies a private-label version of Xience V, called the Promus Everolimus-Eluting Coronary Stent System, to Boston Scientific as part of a distribution agreement established between the two companies last year.
Spirit First was a first-in-man study comparing the Xience V Everolimus Eluting Coronary Stent System with the Multi-Link Vision metallic stent system. Spirit First demonstrated positive results with one MACE event at one year and no additional MACE events out to three years. In addition, the number of late stent thromboses in the Xience V arm of the Spirit First trial was zero out to three years of clinical follow-up.
Spirit II is a 300-patient randomized, single-blind, prospective clinical trial evaluating Xience V versus Taxus in Europe and Asia Pacific, in which XIENCE V demonstrated superiority in the primary endpoint of in-stent late loss at 6 months, and clinical superiority on MACE with a 71 per cent reduction compared to Taxus at one year.
Spirit III is a large-scale pivotal clinical trial comparing Xience V to Taxus in the United States and Japan that demonstrated superiority to Taxus in the on the study's primary endpoint of in-segment late loss at eight months with a statistically significant 50 per cent reduction in late loss compared to Taxus.
Abbott's robust post-approval program is projected to enroll over 13,000 Xience V patients across a variety of planned clinical trials. Spirit IV is a 3,690-patient continued access trial that is currently enrolling patients and will evaluate the safety and efficacy of Xience V for the treatment of coronary artery disease in a more complex patient population in the United States. Spirit V is an international clinical trial that will provide additional clinical experience with Xience V in approximately 3,000 patients at approximately 100 clinical sites throughout Europe, Asia, Canada and Latin America. Xience V Spirit Women is the world's first drug eluting stent trial to study only women and will evaluate the characteristics of 2,000 women undergoing stent implantation as well as the performance of Xience V in those patients in Europe, Asia-Pacific, Canada and Latin America. Xience V USA is a post-approval trial planned for the US with 5,000 patients.
Abbott Vascular, a division of Abbott, is one of the world's leading vascular care businesses. Abbott Vascular is uniquely focused on advancing the treatment of vascular disease and improving patient care by combining the latest medical device innovations with world-class pharmaceuticals, investing in research and development, and advancing medicine through training and education. Headquartered in Northern California, Abbott Vascular offers a comprehensive portfolio of vessel closure, endovascular and coronary products that are recognized internationally for their safety and effectiveness in treating patients with vascular disease.