Cook Medical and Angiotech Pharmaceuticals recently announced 2 year follow up for the Zilver PTX drug eluting (Palcitaxel) stent in the superficial femoral artery. The trial is created to assess the safety and effectiveness in treating PAD. Safety and effectiveness have previously been determined iin the coronary circulation only to be followed subsequently by concerns of acute thromboses which occurred at a higher rate relative to bare metal stents.
Paclitaxel, an anti-neoplastict agent, has shown a significant benefit in reducing in stent re-stenosis, the "achilles heal" of percutaneous stenting. Previous trials have shown questionable benefit of drug eluting stent technology in the infra inguinal circulation.
– Angiotech Pharmaceuticals, Inc. (NASDAQ: ANPI, TSX: ANP) today
announced its corporate partner, Cook Medical, reported data on two-year follow up that showed that 82
percent of patients who were treated with Cook Medical's Zilver® PTX™ drug-eluting peripheral stent (DES)
were free from reintervention at two-year follow up. The Zilver PTX Registry study, involving 792 patients
from across the world, is assessing the safety and efficacy of the Zilver PTX in treating PAD. The most recent
results were reported at the 31st International Symposium: Charing Cross Controversies Challenges Consensus.
“These results are extremely encouraging as it's the first time paclitaxel-coated stents have been used in the
treatment of blockages in arteries outside the heart,” said Zilver PTX global principal investigator, Dr. Michael
Dake, Professor in the Department of Cardiothoracic Surgery at Stanford University Medical School and
Medical Director of the Cath/Angio Laboratories at Stanford University Medical Center. “Patients treated with
the Zilver PTX had a very low complication rate and required fewer reinterventions.”
Data was compiled at 12 and 24 months for 593 patients and 177 patients respectively from the registry study,
which enrolled a broad spectrum of patients, including those with complex lesions (e.g., long lesions, total
occlusions, in-stent restenosis). The corresponding event-free survival (EFS) rates were 87 percent and 78
percent, and freedom from TLR (target lesion revascularization) was 89 percent and 82 percent. Clinical
measures that included ankle-brachial index, Rutherford score, and walking distance and speed scores showed
significant improvement at six and 12 months and were maintained through 24 months.
Detailed evaluation of stent x-rays demonstrated excellent stent integrity through 12 months, confirming
previously published results showing 99 percent completely intact stents with a mean follow up of 2.4 years in
the challenging superior femoral artery and popliteal arteries, including behind the knee locations.
One in five in the 65- to 75-year-old age group in the UK* has peripheral arterial disease (PAD). Yet only a
quarter of these people have any symptoms at all. The 'silent' nature of this condition can result in a number of
patients being diagnosed only when their condition has progressed to the severe stage. In patients with severe
PAD whose condition is not improving with risk-factor modification, exercise programs and pharmacological
therapy, invasive procedures may need to be carried out. These procedures include angioplasty, stenting or
surgery.
“We are impressed with both the efficacy and durability demonstrated by the Zilver PTX in the registry study
and believe we will see similar results in the US randomized trial which is currently ongoing,” said Dr. Bill
Hunter, President and CEO of Angiotech. “Our partner, Cook Medical, has been committed to continually
improving the efficacy and safety of peripheral DES and early results suggest that the self-expanding, Zilver
PTX stent will be an important treatment option for patients with PAD.”
In addition to the registry arm of the study, the 480 patient randomized component is designed to evaluate the
Zilver PTX across 45 trial sites in the United States, Japan and Europe. Of the 480 patients enrolled in the
randomized study, 240 received the Zilver PTX DES. Enrollment in the randomized study was completed in
2008. For more information, please visit www.zilverptxtrial.com.
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