Abbott Vascular’s Xience V stent has been shown to be superior to other drug-eluting devices in two trials reported at the Transcatheter Cardiovascular Therapeutics 2009 annual meeting in San Francisco, California, USA.
The first trial, SPIRIT IV, presented during the late-breaking clinical trials session on Wednesday 23 September, demonstrated that Abbott’s market-leading Xience V everolimus-eluting coronary stent system achieved superiority in the key safety and efficacy measures of target lesion failure (TLF) and target lesion revascularisation (TLR) compared to the Taxus Express2 (Boston Scientific) paclitaxel-eluting coronary stent system (Taxus) at one year. With 3,690 patients, the SPIRIT IV trial is one of the largest randomised clinical trials between two drug-eluting stents.
In the trial’s primary endpoint, Xience V demonstrated a statistically significant 38% reduction in TLF compared to Taxus (4.2% for Xience V vs. 6.8% for Taxus, p=0.001). TLF is defined as a composite measure of important efficacy and safety outcomes for patients and is defined as cardiac death, target vessel myocardial infarction, and ischaemia-driven TLR (ID-TLR). The standard was established to harmonise the definition of major adverse cardiac events across various drug-eluting stent trials. Xience V also demonstrated a statistically significant 46% reduction in TLR compared to Taxus (2.5% for Xience V vs. 4.6% for Taxus, p=0.001). TLR is one of the major secondary endpoints of the SPIRIT IV trial. The groundbreaking results were presented by Gregg W Stone, professor of medicine at Columbia University Medical Center.
In addition to demonstrating superiority in the primary endpoint of TLF and major secondary endpoint of TLR, Xience V demonstrated an impressive low rate of stent thrombosis (0.17% for Xience V vs. 0.85% for Taxus, p=0.004) at one year.
“SPIRIT IV represents one of the largest randomised trials of two drug-eluting stents completed to date. Importantly, this study was performed without routine angiographic follow-up, which may result in a tendency to treat lesions which may not be causing symptoms, and potentially impact results,” said Stone, “The SPIRIT IV results show that Xience V significantly reduces a patient’s risk of experiencing a heart attack, the need for a repeat procedure or stent thrombosis.”
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.
Boston Scientific recently announced that on 1 October 2009 it would begin its previously planned, phased discontinuation of the Taxus Express Stent used in the SPIRIT IV trial. The Taxus Express stent has been replaced by the thinner-strut Taxus Liberte stent worldwide.
Key results from the SPIRIT IV trial
In the SPIRIT IV trial of 3,690 patients, Xience V demonstrated the following key results at one year:
- A 38% reduction in TLF compared to Taxus (4.2% for Xience V vs. 6.8% for Taxus, p=0.001).
- A 39% reduction in major adverse cardiac events (MACE) compared to Taxus (4.2% for Xience V vs. 6.9% for Taxus, p=0.0009). MACE is a composite clinical measure of safety and efficacy outcomes for patients, defined as cardiac death, heart attack (myocardial infarction or MI), or ID-TLR driven by lack of blood supply.
- A 46% reduction in TLR compared to Taxus (2.5% for Xience V vs. 4.6% for Taxus, p=0.001).
- A 31% reduction in cardiac death or target vessel myocardial infarction (MI) compared to Taxus (2.2% for Xience V vs. 3.2% for Taxus, p=0.09).
- A 38% reduction in heart attacks (MI) attributed to the target vessel compared to Taxus (1.8% for Xience V vs. 2.9% for Taxus, p=0.04).
- Comparable rates in cardiac death compared to Taxus (0.4% for Xience V vs. 0.4% for Taxus, p=1.00).
- An observed 80% reduction in stent thrombosis per protocol definition compared to Taxus (0.17% for Xience V vs. 0.85% for Taxus, p=0.004).
- An observed 74% reduction in stent thrombosis per ARC definition of definite/probable stent thrombosis compared to Taxus (0.29% for Xience V and 1.10% for Taxus, p=0.004).
The second trial presented at the late-breaking trial session, the COMPARE trial, demonstrated that Xience V further demonstrated significantly better outcomes in key safety and efficacy measures compared to Taxus. At one year, Xience V demonstrated a significantly lower incidence of major adverse cardiac events (MACE) compared to Taxus (6.2% Xience V vs. 9.1% Taxus, p=0.023) in the trial’s primary endpoint, which is a composite of all death, non-fatal myocardial infarction and target vessel revascularisation (TVR). Additionally, Xience V demonstrated a significantly lower rate of stent thrombosis compared to Taxus (0.7% Xience V vs. 2.6% Taxus, p=0.002), a significantly lower rate of TVR (2.4% Xience V vs. 6.0% Taxus, p=0.0001), and a significantly lower rate of TLR (1.7% Xience V vs. 4.8% Taxus, p=0.0002). The results were presented by Peter Smits, Maasstad Ziekenhuis, Rotterdam, the Netherlands.