Interventional News reports on three company-sponsored trials that are evaluating the use of drug-coated stents (Cook) and stenting vs. angioplasty (Cordis) in the treatment of peripheral arterial disease.
The first patient has been treated in the Cook ZILVER PTX trial in the above knee SFA, evaluating a drug-coated stent from Cook Incorporated for peripheral arterial disease, at Stanford University Medical Center. The trial is the first US trial ever to test whether drug eluting stents, which have shown clinical success in treating coronary artery disease, can have similar benefits in treating arteries outside the heart. The elderly female patient was treated by a team of doctors led by Dr Michael D Dake, Professor and Chairman of the Department of Radiology at the University of Virginia Health System and national principal investigator, and Daniel Sze, Associate Professor of Radiology at Stanford University Medical Center and principal investigator for the trial at Stanford.
The trial is designed to determine the safety and effectiveness of the Zilver PTX paclitaxel-eluting stent to clear blockages above the knee in the femoropopliteal artery. To prevent the renarrowing of the artery, the Zilver PTX is coated with paclitaxel, a drug approved for clinical use as an anti-cancer agent and used successfully with coronary stents to reduce the risk of renarrowing of the artery. The Zilver PTX trial is being conducted initially in ten US medical facilities and will enrol 60 patients, with an expanded trial likely pending further FDA review.
The study compares the safety and effectiveness of the drug-eluting stent to standard peripheral arterial disease interventions. Cook hopes to complete enrolment in the pilot study by the end of 2005 and complete enrolment in the pivotal study by the end of 2006. The trial data will be used to apply for FDA approval of the device for US sale.
The Zilver PTX stent is an investigational device not approved for sale in the US.
Dake said drug-eluting stents are the primary therapy for obstruction in the coronary circulation and it is hoped similar technology, used in the legs, will help those who suffer from peripheral arterial disease.
"The patient treated with the Zilver PTX stent underwent surgical aortoilliac revascularisation previously, but still experienced pain after walking one-and-a-half miles. We will eagerly anticipate her outcome as we follow the trial," Dake added.
Cook has also revealed that it will enrol 760 patients at up to 50 investigational sites in Europe, Asia, Australia and Canada, in an international clinical trial that will determine the safety and effectiveness of the Zilver PTX paclitaxel-eluting stent to clear blockages above the knee in the femoropopliteal artery. Cook holds a co-exclusive license from Angiotech Pharmaceuticals for the use of paclitaxel in the peripheral vascular and gastrointestinal fields of use.
Separately, Cordis Corporation (a Johnson & Johnson company) has launched the SUPER SL Study, which will compare their SMART Nitinol Stent System with Bard Luminexx Vascular Stent for treatment of superficial femoral artery stenosis and occlusions of peripheral arterial disease (PAD).
Investigators across 13 centres in Germany are undertaking the randomised, two-arm trial which will target longer lesions (up to 22cm), which are classed as 'C' and 'D' lesions by the TransAtlantic Inter-Society Consensus (TASC) and are traditionally referred for bypass graft surgery.
After one-to-one randomisation and treatment, patients will be followed up at six and 12 months to evaluate primary patency defined as presence of flow through the index lesion. Secondary end points in the trial include technical success during deployment of the stent, procedural success and x-ray assessment for the detection of stent fractures at six and 12 months.
The first patient in the study underwent treatment during a live case at EuroPCR, by co-principal investigator Dr Dierk Scheinert. He said that SUPER SL could change treatment of patients with longer lesions.
"It has the potential to deliver the evidence required to support the routine use of minimally invasive percutaneous transluminal intervention in patients who would otherwise have needed to undergo surgery," Scheinert said.
Meanwhile, Cordis is also sponsoring the SUPER Study, a new prospective randomised trial in the UK comparing stenting with balloon angioplasty in patients with superficial femoral artery occlusions caused by PAD. The study is a multicentre trial that will compare patency rate at one year after percutaneous transluminal angioplasty or stent placement with the Cordis Endovascular Smart nitinol self expandable.
The trial is a two-arm study that will compare stenting versus ballooning in approximately 150 patients with symptomatic peripheral vascular disease with superficial femoral artery occlusions across 12 UK centres. Patients will be followed for 12 months post procedure and the primary endpoint is primary patency at one year demonstrated by ultrasound.
Secondary objectives include the evaluation of clinical status and quality of life of the patient at discharge, three, six, nine and 12 months after the procedure, and evaluation of the cost effectiveness of both stenting and angioplasty.
An estimated 102,000 people are diagnosed with PAD each year in the UK and risk factors include age, smoking, hypertension, hyperlipidaemia, diabetes, and family history. PAD may be asymptomatic, but commonly presents with intermittent claudication or pain at rest. In 3-6% of cases complications arising through PAD lead to ulceration, gangrene and amputation of the affected limb. Current treatment options include disease management through lifestyle changes and medication, minimally invasive percutaneous transluminal angioplasty or major surgery such as bypass grafts. Percutaneous transluminal angioplasty has lower morbidity, quicker recovery and reduced hospital stay compared with major surgery, however reocclusion may occur within six to 24 months of treatment.
"Stenting has never gained widespread acceptance in the superficial femoral artery due to the high rate of early reocclusion in previous series. New stent designs appear to give better midterm patency rates and we are interested to find out whether or not there is appreciable benefit compared with balloon angioplasty alone, in those patients who have total occlusions of the superficial femoral artery," explained Dr Nick Chalmers, consultant vascular radiologist, Manchester Royal Infirmary, and co-principal investigator SUPER Study.
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