|Cook demonstrated a successful Zilver PTX trial for the treatment of peripheral artery disease.--Courtesy of Cook Medical|
Coming off an FDA recall in April just months after winning U.S. approval, Cook Medical has had a lot to prove to drag its Zilver PTX drug-eluting stent back into the agency's better graces. This week, the company heralded results from a four-year trial that showed, despite its delivery system failures in the past, the paclitaxel-eluting device was more effective at preventing restenosis than a bare metal stent.
The four-year, 479-patient study at sites across the U.S., Europe and Japan investigated Zilver PTX's use as a treatment for peripheral artery disease in the superficial femoral artery, according to the company. The device showed 75% primary patency--effectively opening the artery--over four years compared with about 58% from a provisional bare metal stent. Additionally, 83.2% of Zilver PTX patients did not require revascularization after four years, as opposed to 69.4% with other treatments.
When it won FDA approval in November last year, Zilver PTX was the first drug-eluting stent cleared to treat peripheral artery disease. But just several months later, Cook was defending the device, which in rare cases had been found to separate from the delivery catheter used to place it in the artery.
Bloomington, IN-based Cook hopes to bolster confidence in Zilver PTX after the FDA issued a Class I--the most serious--recall of the device for reported delivery-system failures resulting in two adverse events, one of which involved a patient's death. Although the company did not acknowledge there was enough evidence to confirm that the delivery failure led to the adverse events, it did claim to have identified the flaw with the delivery system at the time.
"The four-year freedom from [target lesion revascularization] data documents the sustained clinical benefit of Zilver PTX," said data presenter Michael Dake, a cardiothoracic surgery professor at Stanford University Medical School, who acted as Cook's paid consultant. "When compared to standard of care therapy, consisting of either acutely successful [percutaneous transluminal angioplasty] or provisional bare stent placement after sub-optimal PTA, the paclitaxel-eluting Zilver stent provides a 45% reduction in the reintervention rate in this study."
"With these new data showing lasting patency at four years," said Cook VP Rob Lyles, "we're confident our Zilver PTX stent offers PAD patients a lasting solution."
- here's the release