A year after an FDA panel unanimously recommended its approval, Cook Medical’s Zilver PTX has finally become the first drug-eluting stent to gain US approval for peripheral arterial disease.
The paclitaxel-coated device, designed to be implanted in the superficial femoral and proximal popliteal arteries, will reach the US in a stepwise launch, and is likely to sell well. According to EvaluateMedTech, no other drug-eluting stents are even in late-stage development for use in the peripheral arteries; if Zilver PTX shows the same advantages over bare-metal stents and balloon angioplasty that were seen with coronary drug-eluting stents it will change the way peripheral arterial disease is treated in the US.
First of its kind
Disease in the proximal femoropopliteal artery – the part above the knee – is considered difficult to treat; this part of the artery is pulsatile and flexible to such a degree that early stents had a high fracture rate, making trials difficult to interpret as the stents did not last long enough to assess the effects of the drug.
Zilver PTX is composed of the shape-memory alloy Nitinol, and does not employ a polymer to link the drug to the metal struts. Stent polymers have been linked with thrombosis, which can strike many months after the stent has been implanted.
At the moment, in the US the options for treating the proximal femoropopliteal artery include balloon angioplasty with or without bare-metal stents, drug therapy, or surgical bypass. Medtronic and C. R. Bard are developing drug-coated balloons for peripheral arterial disease, but no other drug-eluting stents are likely to reach the US for many years.
In Europe, Zilver PTX has been available since September 2009. Cook is a private company and does not release sales figures, but Zilver PTX has met with success in clinical trials and uptake ought to have been good.
US sales will be slightly truncated by the FDA’s contraindications: the device may not be used in people who cannot receive anticoagulants owing to bleeding disorders, or women who are pregnant, breastfeeding, or plan to become pregnant within five years. However, since peripheral arterial disease mainly strikes elderly patients, this should not limit Zilver PTX’s potential patient population too much.
In granting the premarket approval (PMA), the FDA stipulated that Cook Medical conduct a five-year postmarketing study involving 900 patients to monitor the safety and efficacy of the device further.
In the US, 8 to 12 million people have peripheral arterial disease, according to the American College of Cardiology. The US peripheral vascular device market is worth around $3bn, reaching more than $5bn by 2016, though this includes products such as stent-grafts for abdominal aortic aneurysms.
In a move that looks likely to improve the distribution of Zilver PTX, Cook has also signed a contract with the healthcare supply chain company Novation for its peripheral intervention and peripheral diagnostic devices. The products will be distributed to more than 65,000 hospitals and institutions served by Novation.
Zilver PTX comes in several sizes, and the 80mm length in 6mm and 7mm diameters will be launched first; two 80mm stents may be overlapped to treat lesions up to 140mm long. In early 2013, Cook will launch 40mm and 60mm lengths, which are included in the current approval. The company also expects to receive a separate regulatory approval for an 120mm long version in both diameters next year.
This full suite of stents in the most commonly used lengths and diameters could see Cook going for gold next year.
To contact the writer of this story email Elizabeth Cairns in London at firstname.lastname@example.org