A Medical Device Daily
Medtronic (Minneapolis) reported the target lesion revascularization (TLR) rate for the company's Endeavor drug-eluting stent in the real-world Danish trial, SORT OUT III, was 4% at the Transcatheter Cardiovascular Therapeutics (TCT) Scientific Symposium last week in Washington.
This result at nine months is consistent with the ENDEAVOR-Five real-world study, which reported an overall TLR of 4.5% at 12 months. The rates of myocardial infarction in the SORT OUT III study were very low for both the Endeavor (1.4%) and Cypher (0.5%) stents. The rate of stent thrombosis in SORT OUT III for Endeavor was 1.2% (ARC definite), consistent with typical rates of stent thrombosis for both drug-eluting and bare-metal stents after nine months of patient follow up.
Surprisingly, however, the SORT-OUT III study at nine months reported a 1% TLR rate for Cypher, considerably less than the 4.5% TLR reported in the similar SORT OUT II study (Galloem et al, JAMA 2008) previously conducted in the same five centers by the same group. In addition, the stent thrombosis rate for the Cypher stent was 0.2%, compared to 1.7% reported in the SORT OUT II study.
Jens Flensted Lassen, the study investigator said, "We were very surprised by these results – specifically those for Cypher and especially compared to the SORT OUT II data." It was also noted during the presentation that late stent thrombosis becomes meaningful as a safety signal only after one year.
"We expect a negative but manageable impact from these studies," said Larry Biegelsen, senior analyst, medical supplies & devices, Wachovia Capital Markets (Charlotte, North Carolina). "We forecast worldwide Endeavor sales of $674 million in FY09 or about 4% of total MDT sales. We think this data will probably shave a few share points off Endeavor's share in the U.S. and Europe."
Lassen commented on the safety outcomes in the study, which reported stent thrombosis for Endeavor of 1.2% at nine months, "This is only half the story, as we saw with ENDEAVOR IV, we expect late catch-up with Cypher."
Lassen's comments acknowledge that while early events were also seen with Endeavor in the ENDEAVOR IV study at 12 months, there were no instances of late stent thrombosis with Endeavor after 369 days, in follow up to two years.
Medtronic soon will complete enrollment in the PROTECT clinical study. The PROTECT study is the largest randomized trial focusing on the safety of drug-eluting stents. This 8,800-patient trial is being conducted at 200 centers worldwide and will compare Medtronic's Endeavor stent and Cypher, made by Cordis (Miami Lakes, Florida), using key safety endpoints and other clinically relevant outcomes. The primary endpoint for the PROTECT study will be overall stent thrombosis at three years.
In other news from TCT:
• Lumen Biomedical (Plymouth, Minnesota) reported that principal investigator Subbarao Myla, MD, presented the results from the EPIC Clinical Trial: Evaluating the Use of the FiberNet Embolic Protection System in Carotid Artery Stenting.
From March 2007 to May 2008, the multi-center, single-arm EPIC clinical trial evaluated the FiberNet Embolic Protection System (EPS) during carotid artery stenting of 237 high surgical risk patients with a critical carotid artery stenosis.
The FiberNet EPS captures particles released during the carotid artery stenting procedure with a filter made of a 3-D matrix of fibers, designed to prevent microscopic debris from traveling to the brain. After the particles have been captured, the FiberNet filter is then retrieved into the retrieval catheter, Lumen Biomedical's FDA-cleared Xtract Aspiration Catheter, and removed from the patient.
The mean age of the patients participating in the clinical trial was 74 years (21% were octogenarians), 64% male and 20% were symptomatic.
Overall, the combined major adverse event rate at 30 days for all death, stroke and myocardial infarction was 3%. There were five strokes for a 30-day stroke rate of 2.1%. There were no unanticipated adverse device effects. The results demonstrate that FiberNet EPS' unique features may contribute to a lower stroke rate during carotid artery stenting in high surgical risk patients, according to the company.
• Stentys (Paris) reported clinical data from the OPEN I clinical study using its bifurcated stent. That data — presented by Stefan Verheye, MD, of Antwerp, Belgium — considered safety results 30 days post-implantation of the Stentys bifurcated stent in a total of 40 patients.
The stent was successfully deployed in 39 of the 40 patients, leading to an overall 98% procedural success rate.
An increase of cardiac enzymes (non-Q wave MI) was observed during only one procedure out of 40, without any clinical consequences for the patient. One other patient had to undergo balloon angioplasty one week after the initial procedure.
Verheye concluded that the Stentys stent is safe, provides side branch access and allows provisional treatment of branch vessels. The stent with its self-expanding properties conforms "very nicely to the complex peri-carinal vessel anatomy."
"The Open I study demonstrates that the Stentys bifurcated stent can be simply and safely implanted in patients with complex bifurcation lesions," said CEO/co-founder Gonzague Issenmann. "The Stentys stent offers a simple consistent stenting strategy, the enhanced provisional technique' that allows cardiologists to keep all options open throughout the procedure for optimal vessel treatment."
• L. Nelson Hopkins, MD, of the University of Buffalo and national co-principal investigator, presented positive results of the Gore EMPiRE Clinical Study, designed to demonstrate the safety and efficacy of the GORE Flow Reversal System for neuroprotection during carotid artery stenting (CAS) in patients at high risk for carotid endarterectomy.
The GORE Flow Reversal System, made by W. L. Gore & Associates (Flagstaff Arizona) provides neuroprotection by reversing the flow of blood at the carotid stenosis, thereby directing embolic particles away from the brain.
The study met the primary endpoint of major adverse events of death, stroke, transient ischemic attack and myocardial infarction (MI). The 30-day stroke, death, and MI rate was 3.7% (4.5% including TIA) and the death / any stroke rate was 2.9%.
Importantly, the study also showed encouraging results in some of the most challenging patient populations with a low death, stroke, and MI rate of 2.6% for octogenarians and 3.8% for symptomatic patients. The results of the pivotal Gore EMPiRE Clinical Study were based on the enrollment of 245 patients at 28 clinical sites.