Cook Medical has completed enrolment in the first international clinical trial of the Zilver PTX, a drug-eluting stent designed to treat arterial blockages outside coronary arteries.
The 420 patients enrolled in Cook's randomised trial of the Zilver PTX include peripheral arterial disease (PAD) patients treated in Germany, the United States and Japan.
In many cases, PAD patients who have been treated with balloon angioplasty and stenting experience restenosis, or re-narrowing of the arteries, over time and must undergo more invasive treatment such as bypass surgery to restore blood flow to key arteries.
The Zilver PTX trial is designed to determine whether the combination of Cook's Zilver stent and a paclitaxel coating will keep peripheral arteries, specifically the superficial femoral artery (SFA), open over time.
The self-expanding nitinol stent, uses a proprietary, polymer-free technology to coat the device with paclitaxel, an antiproliferative drug that has been used successfully to reduce the risk of renarrowing of arteries following angioplasty in coronary disease patients.
Cook's ability to adhere the drug to the stent body without using a polymer may be a major clinical advantage, since it eliminates the risk some patients may face due to allergic reactions and other potentially poor outcomes that may be associated with the polymer coatings used on the current generation of drug-eluting coronary stents.
Cook licenses the rights to use paclitaxel on peripheral stents and other non-coronary medical devices from Angiotech Pharmaceuticals of Vancouver, British Columbia, Canada.
Cook has enrolled an additional 780 patients in the European Union, Canada, and Korea in a clinical registry to evaluate the safety of the Zilver PTX device.
Those data have been used for a submission in Europe for CE Mark approval to market the device there, with additional regulatory submissions pending in additional markets.
In addition, the stent already has regulatory approval for commercial use in New Zealand, Hong Kong and Singapore, where it has been used to treat patients suffering with peripheral arterial disease.
Preliminary findings presented by Michael Dake MD, professor of radiology, internal medicine and surgery and chairman of the department of radiology at the University of Virginia Health System, at the Society for Vascular Surgery (SVS) meeting in June revealed clinical improvement in patients treated with the Zilver PTX, 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, Dake reported to his medical colleagues at the SVS event.
