Speculation on possible benefits
The results from the European first-in-man study of the Vascular Wrap paclitaxel-eluting (Angiotech Pharmaceuticals) device have revealed that the Vascular Wrap reduced the overall incidence of leg amputation and prolonged limb retention time for patients in the treatment arm relative to the control group.
The Vascular Wrap paclitaxel-eluting mesh/ePTFE graft combination product technology is designed for use in haemodialysis access and peripheral arterial bypass surgery. It is a combination product consisting of both the ePTFE graft and the Vascular Wrap paclitaxel-eluting mesh. The Vascular Wrap component is a biodegradable mesh implant incorporating Angiotech’s paclitaxel technology in a novel biomaterial with the goal of mitigating scar formation caused by abnormal blood flow, thereby potentially enhancing graft patency rates in AV-access patients as well as in peripheral bypass procedures.
This single-blind study enrolled a total of 109 patients at nine clinical centres in Europe as well as the Dutch Antilles and randomised patients with peripheral vascular disease in a 2:1 fashion. The treatment arm enrolled patients with a synthetic bypass graft plus the Vascular Wrap paclitaxel-eluting mesh and the control arm enrolled patients with a synthetic bypass graft alone. The objectives of this two-year study were to assess the safety and clinical performance of the Vascular Wrap in combination with an ePTFE vascular graft following surgery to treat patients suffering from advanced peripheral arterial disease in their lower limbs.
The trial results showed that the Vascular Wrap is well tolerated and adverse events leading to death occurred in a lower percentage of treated subjects (11%, 8/71), than in controls (18%, 7/38). No adverse events were considered by the investigators to be related to the use of the Vascular Wrap. Overall, the action taken to resolve adverse events was similar for the two groups, and the outcomes were similar.
When comparing the treatment arm relative to the control, the Vascular Wrap maintained the mean diameter of the distal anastomosis during the 24 month trial compared to a decrease in mean diameter in the control arm. This reached statistical significance (p=0.0333). The Vascular Wrap trial also produced evidence of improved patient outcomes, with the overall incidence of amputation and prolonged limb retention time. The control group had an almost higher probability of amputations compared to the treatment arm 18.4%, 7/38 vs. 15.5%, 11/71 subjects). For the patients that underwent an amputation during the study period, the mean interval to amputation for patients treated with the Vascular Wrap was 156 days, more than double the mean interval to amputation for the control, which was 76 days. While the sample size was small, diabetic subjects appeared to experience benefits from the Vascular Wrap.
Dr William Hunter, President and CEO of Angiotech, commented: “It appears from this trial that being treated with our Vascular Wrap provides patients with an option to better manage their disease, and a much greater chance of retaining their leg for a longer period of time following synthetic bypass grafting.”
The company has submitted an application for CE mark approval for its Vascular Wrap paclitaxel-eluting mesh/ePTFE vascular graft combination product on the strength of the results from its European first-in-man study.
Angiotech believes the acquisition of the vascular graft product line from Edwards Lifesciences in 2005, as well as the acquisition American Medical Instruments, leaves the company well positioned to capitalise on and economically benefit from this potentially category-defining product. “The market potential for our Vascular Wrap product could be significant. With the results from the two-year European study and our upcoming trials in AV Access in the UK and US, we believe that we have the potential to build a significant vascular franchise,” he added.