June 12, 2008 – The registry arm of a clinical study to assess the safety and effectiveness of Cook Medical’s Zilver PTX Drug-Eluting Peripheral Stent (DES) in treating peripheral arterial disease (PAD) has yielded positive interim results, trial investigators reported at the 2008 SVS Vascular Annual Meeting last week.
The findings, presented by Michael Dake, M.D., professor of Radiology, Internal Medicine and Surgery and chairman of the Department of Radiology at the University of Virginia Health System, reveal clinical improvement, excellent stent durability (i.e., fracture resistance), high rates of event-free survival (EFS) and freedom from target lesion revascularization (TLR). This preliminary information suggests no safety concerns, and promising effectiveness results.
“Cook's registry study and randomized trial are the first to use a paclitaxel-coated stent in the treatment of arterial blockages outside the heart,” said Dr. Dake, the trial’s global principal investigator. “They are designed to evaluate the safety and effectiveness of DES technology versus percutaneous transluminal angioplasty, and our initial findings in the registry arm give us every reason to believe that Zilver PTX may have the integrity, safety and durability needed to successfully address many of the well-known limitations of angioplasty alone for management of PAD.”
Interim data were compiled at six and 12 months for 435 patients and 200 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 EFS rates were 94 percent and 84 percent, and freedom from TLR was 96 percent and 88 percent. Clinical measures that included ankle-brachial index, Rutherford score, and walking distance and speed scores showed significant improvement at six months and was maintained through 12 months.
Evaluation of stent x-rays is ongoing, and currently suggests stent fractures in only about one percent of cases at six months and less than two percent of cases at 12 months. Follow-up in the registry arm of the study will continue through two years.
“We are quite pleased with this first round of data from the registry portion of the study, and are optimistic we’ll encounter similar results throughout the duration of the Zilver PTX trial,” said Rob Lyles, global leader of Cook Medical's Peripheral Intervention products division. “At Cook, we are continually driving to improve the quality of our products and, in turn, improve the quality of patient outcomes. We are particularly excited about the potential benefits our self-expanding Zilver PTX stent provide can patients suffering from PAD.”
The clinical study is designed to evaluate the Zilver PTX in more than 1,000 patients across 89 trial sites in the United States, Asia, Latin America, Canada and Europe. In addition to the 790 DES patients enrolled in the registry arm of the study, approximately 240 of the 480 patients to be enrolled in the randomized arm of the study will receive the DES. Follow-up is ongoing for the registry, while enrollment in the randomized study is expected to be complete within the coming months.
For more information, visit www.cookmedical.com and www.zilverptxtrial.com