Abbott announced the start of the Xience V USA post-approval study, with six hospital centres already recruiting and enrolling patients just one week after the US Food and Drug Administration approved the Xience V Everolimus Eluting Coronary Stent System.
The Xience V USA study will evaluate the safety and effectiveness of the Xience V drug eluting stent in a real-world clinical setting out to five years. Jack Jones, M.D., interventional cardiologist and medical director of the Stormont-Vail Catheterization Lab in Topeka, Kansas, was one of the first physicians to enrol a patient into the study.
"Xience V is an important innovation that gives patients in the United States access to a next-generation drug eluting stent that has been shown in clinical trials to improve patient outcomes," said Dr. Jones. "During the stent procedure, we found it easy to deliver Xience V to the diseased portion of the vessel. With its combination of clinical efficacy and deliverability, I believe that Xience V will become a key advancement in the treatment of coronary artery disease."
The Xience V USA study is designed to evaluate at least 5,000 coronary artery disease patients treated with the Xience V drug eluting stent at approximately 250 centres across the United States. The primary endpoint of Xience V USA is a measure of stent thrombosis (formation of blood clots) every year out to five years, as defined by the Dublin/Academic Research Consortium (ARC). The ARC definition of late stent thrombosis was developed to eliminate variability in the definitions across various drug eluting stent trials.
The co-primary endpoint of the study is the composite rate of cardiac death and any heart attack (Q-wave or non-Q-wave myocardial infarction) in patients at one year. Secondary endpoints of the study include patient compliance with prescribed anti-platelet medication, measures of re-treatment by stenting or surgery, and device and procedural success.
"Post-approval studies allow physicians to follow the safety and efficacy of new treatments in a more complex patient population than is typically studied in pre-approval clinical trials. Xience V USA will provide significant insight about the performance of Abbott's new drug eluting stent in a variety of patients," said Charles Simonton, M.D., FACC, FSCAI, divisional vice president, Medical Affairs and chief medical officer, Abbott Vascular. "Our ability to work with our physician partners to begin this post-approval study within days of FDA approval is further evidence of Abbott's commitment to help the interventional cardiology community gain additional insights about the clinical benefits of Xience V."
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. Xience V is built upon Abbott's market-leading bare metal stent, the MULTI-LINK VISION Coronary Stent System. The VISION platform is designed to facilitate ease of delivery, making it easier for physicians to maneuver the stent and treat the diseased portion of the artery.
Long-term results with Xience V in the SPIRIT III pivotal US clinical trial demonstrated a 45 per cent reduction in the risk of major adverse cardiac events (MACE) compared to the TAXUS paclitaxel-eluting coronary stent system at two years. Xience V demonstrated a 32 percent reduction in target vessel failure (TVF, cardiac events related to the stented vessel) compared to TAXUS at two years. Xience V also demonstrated a low rate of stent thrombosis between one and two years, defined as very late stent thrombosis, per Academic Research Consortium (ARC) definition of definite/probable stent thrombosis (0.3 per cent for Xience V and 1.0 per cent for TAXUS). Xience V met its primary endpoint in the SPIRIT III clinical trial with a statistically significant 50 percent reduction in in-segment late loss (vessel renarrowing) at eight months compared to TAXUS.
The Xience V stent is available on both over-the-wire (OTW) and rapid exchange (RX) delivery systems. Rapid exchange is the most widely used type of delivery system because it provides physicians additional flexibility to work as single operators during stent procedures.
Xience V was approved by the US Food and Drug Administration on July 2, 2008, and was launched in Europe and other international markets in October 2006. Xience V is an investigational device in Japan and is currently under review by the Ministry of Health, Labour and Welfare and the Pharmaceuticals and Medical Devices Agency.
Abbott also supplies a private-label version of Xience V to Boston Scientific called the PROMUS Everolimus-Eluting Coronary Stent System. PROMUS is designed and manufactured by Abbott and supplied to Boston Scientific as part of a distribution agreement between the two companies.
Everolimus, developed by Novartis Pharma AG, is a proliferation signal inhibitor, or mTOR inhibitor, licensed to Abbott by Novartis for use on its drug eluting stents. Everolimus has been shown to inhibit in-stent neointimal growth in the coronary vessels following stent implantation, due to its antiproliferative properties.