Angiotech Pharmaceuticals (Vancouver, British Columbia) has begun enrolling patients in its U.S. pivotal study examining the Vascular Wrap paclitaxel-eluting mesh.

The study is intended to evaluate the safety and efficacy of the Vascular Wrap after surgical implantation with an ePTFE vascular graft in the upper extremity for hemodialysis vascular (AV) access. The combination of Angiotech's Vascular Wrap with its VaxSys ePTFE vascular graft will be branded as the VaxSys Synergy product, the company said.

The Vascular Wrap is a biodegradable mesh implant incorporating Angiotech's paclitaxel technology in a biomaterial with the goal of reducing scar formation caused by abnormal blood flow thereby potentially enhancing graft patency rates in AV-access patients as well as in peripheral bypass procedures.

William Hunter, MD, president/CEO of Angiotech, told Medical Device Daily that the study is designed to look at AV access, one of the most common problems associated with arteriovenous grafts.

Hunter said about half of AV grafts fail within a year because of neointimal hyperplasia — scar tissue — at the graft connection site. It's a significant problem, he added, primarily because it costs about $50,000 to replace the graft if it fails.

So what the wrap does, Hunter said, is deliver the drug paclitaxel into the graft site to prevent scarring.

"We believe that the Vascular Wrap within our VaxSys Synergy product holds promise to help those patients with end-stage renal disease [ESRD], who today face the high probability that their AV graft will fail in the first year of use. We believe that our technology has the potential to save dialysis patients with ESRD from repeated surgeries and help reduce the significant human and financial costs of additional hospitalizations," Hunter said.

The study enrolled its first patient last Thursday in Winston-Salem, North Carolina and will involve about 530 patients at 50 centers in the U.S. The study is expected to last about two years.

"The initiation of this study is an important milestone for Angiotech. We believe the Vascular Wrap could not only significantly improve the treatment of hemodialysis patients, but that the commercial opportunity for the VaxSys Synergy product is significant. We hope this study, combined with the results from the two-year European study, will create the foundation for building a highly differentiated vascular franchise," Hunter said.

In November 2006, Angiotech reported results from its European first-in-man study examining the safety and clinical performance of the Vascular Wrap when used to treat patients suffering from advanced peripheral arterial disease (PAD) in their lower limbs (Medical Device Daily, Nov. 10, 2006). The company said that trial "produced evidence" 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. Based on the strength of this two-year data, Angiotech said it submitted an application for a CE Mark for its Vascular Wrap paclitaxel-eluting mesh/ePTFE vascular graft combination product.

The VaxSys Synergy pivotal trial is a randomized, placebo-controlled, multi-center, two-arm study. The primary objective is to demonstrate that the patency of the Vascular Wrap Paclitaxel-Eluting Mesh and the ePTFE graft is superior to the patency of the ePTFE graft alone within one year following vascular access surgery, the company said.

Patients in the study will also be followed over a four-year period to confirm the long-term safety of the study device, although Angiotech expects to file for FDA approval after it completes the primary one-year follow up period.

According to Angiotech, the lives of patients with ESRD are highly dependent on vascular access to facilitate hemodialysis, a method of filtering out toxins in the blood using a dialysis machine. The incidence of ESRD is roughly 100,000 a year and about 330,000 patients require routine hemodialysis. These patients require vascular access through the placement of arteriovenous grafts or the creation of arteriovenous fistulae. In the U.S., synthetic grafts, such as ePTFE, are used in roughly 42% of hemodialysis access procedures, the company said. Almost half of the arteriovenous grafts fail in the first year of use, which is a substantive cause of morbidity and may necessitate medical and surgical intervention in order to maintain graft patency, Angiotech said.