Angiotech Pharmaceuticals, Inc announced its corporate partner, Cook Medical, reported that 82 per cent 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 per cent and 78 per cent, and freedom from TLR (target lesion revascularization) was 89 per cent and 82 per cent. 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 per cent 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 programmes 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. Enrolment in the randomized study was completed in 2008. For more information, please visit www.zilverptxtrial.com.
Angiotech Pharma is a global specialty pharmaceutical and medical device company with over 1,500 dedicated employees.