Patients Treated With XIENCE Drug Eluting Stent Experience Better Outcomes
A study demonstrated that use of Abbott's XIENCE V Everolimus Eluting Coronary Stent System in patients with coronary artery disease resulted in a significant 50 percent reduction in vessel renarrowing (in-segment late loss) at eight months, non-inferior rates of target vessel failure (TVF) at nine months, and an observed 42 percent reduction in major adverse cardiac events (MACE) at one year compared to the TAXUS Paclitaxel-Eluting Coronary Stent System. The SPIRIT III study is a 1,002-patient, prospective, multi-center, randomized clinical trial designed to evaluate the safety and efficacy of the XIENCE V stent system compared to the TAXUS stent system.
"SPIRIT III is the first large-scale clinical trial to show that patients have a lower risk of experiencing a heart attack, cardiac death or re-treatment when treated with a new stent, XIENCE V, compared to the most widely used drug eluting stent TAXUS," said Gregg W. Stone, M.D., of the Columbia University Medical Center; chairman, Cardiovascular Research Foundation, New York; and principal investigator of the SPIRIT III clinical trial. "With a significant reduction in angiographic in-segment late loss, non-inferiority in target vessel failure and a clinical advantage in the composite rate of MACE compared to TAXUS, XIENCE V represents an important advance in improving the lives of patients with coronary artery disease."
The SPIRIT III clinical trial demonstrated the following key results for XIENCE V:
-- Statistical superiority to TAXUS on the study's primary endpoint of in-segment late loss at eight months. XIENCE V demonstrated a statistically significant 50 percent reduction in late loss compared to TAXUS (mean, 0.14 mm for XIENCE V vs. 0.28 mm for TAXUS).
-- Statistical non-inferiority to TAXUS in the major secondary (co-primary) endpoint of target vessel failure (TVF) at nine months. XIENCE V demonstrated an observed 20 percent reduction in TVF compared to TAXUS (7.2 percent for XIENCE V vs. 9.0 percent for TAXUS). TVF is a composite clinical measure of safety and efficacy outcomes defined as cardiac death, heart attack (myocardial infarction or MI) or target vessel revascularization (TVR).
-- An observed 43 percent reduction in the pre-specified secondary endpoint of major adverse cardiac events (MACE) at nine months (4.6 percent for XIENCE V vs. 8.1 percent for TAXUS) and an observed 42 percent reduction in MACE at one year (6.0 percent for XIENCE V vs. 10.3 percent for TAXUS) compared to TAXUS. MACE is an important composite clinical measure of safety and efficacy outcomes for patients, defined as cardiac death, heart attack (MI), or ischemia-driven target lesion revascularization (TLR driven by lack of blood supply).
"The low rate of MACE seen with XIENCE V in the SPIRIT III trial can be directly attributed to fewer patients experiencing heart attacks or re-treatment, and is consistent with data from previous trials," said Charles Simonton, M.D., FACC, FSCAI, divisional vice president, Medical Affairs and chief medical officer, Abbott Vascular. "Superior efficacy combined with increased flexibility and deliverability reinforce that XIENCE V is a significant advancement in stent technology that will be a welcome addition to the field of interventional cardiology."
Additional Results from SPIRIT III
There were no significant differences between XIENCE V and TAXUS in the rates of stent thrombosis either early (less than or equal to 30 days) or late (> 30 days), whether analyzed per protocol or by the Academic Research Consortium (ARC) definition. Rates of definite/probable late stent thrombosis at one year under the ARC definition were 0.5 percent for XIENCE V and 0.6 percent for TAXUS. The ARC definition of late stent thrombosis was developed to eliminate variability in the definitions across various drug eluting stent trials.
In addition, the reduction in in-segment late loss at eight months with XIENCE V compared to TAXUS was consistent across a variety of subgroups in the SPIRIT III trial; however, the SPIRIT III trial was underpowered to measure statistical differences in any of the subgroups.
The SPIRIT III nine-month results were previously reported in March 2007 at the American College of Cardiology's 56th Annual Scientific Session, and the one-year results were previously reported in October 2007 at the Transcatheter Cardiovascular Therapeutics scientific symposium. The SPIRIT III two-year results will be presented in mid-May at EuroPCR 2008 in Barcelona, Spain.
About the SPIRIT III Trial
SPIRIT III is a prospective, multi-center, randomized, single-blind, controlled clinical trial comparing XIENCE V to TAXUS in 1,002 patients (669 XIENCE V patients, 333 TAXUS patients) with either one or two de novo native coronary artery lesions. The trial was conducted across 65 academic and community-based centers in the United States between June 22, 2005 and March 15, 2006. The primary endpoint was in-segment late loss at eight months and the major secondary (co-primary) endpoint was TVF at nine months. An additional pre-specified secondary endpoint included MACE at nine months and one year.
About XIENCE V
The XIENCE V stent 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 other international markets in late 2006. XIENCE V is an investigational device in the United States and Japan, and is currently under review for approval by the U.S. Food and Drug Administration.
Abbott also supplies a private-label version of XIENCE V to Boston Scientific called the PROMUS Everolimus-Eluting Coronary Stent System. PROMUS is designed, studied and manufactured by Abbott and supplied as part of a distribution agreement between the two companies.
Everolimus is licensed to Abbott by Novartis for use on its drug eluting stents.