LeMaitre Vascular (Burlington, Massachusetts) has reported receiving FDA approval for an investigational device exemption supplement to conduct a pivotal trial, named UNITE, of its Aorto-Uni-Illiac Stent Graft.

The graft would be a first for this indication, according to the company.

The study will evaluate the safety and effectiveness of the company's UniFit Abdominal Stent Graft in the treatment of aorto and/or aorto-illiac aneurysms. LeMaitre added the device to its product pipeline when the company acquired Endomed (Phoenix), a maker of endovascular stent grafts for the minimally-invasive treatment of thoracic and abdominal aortic aneurysms, in 2005 (Medical Device Daily, Feb. 11, 2005).

The UniFit Abdominal Stent Graft is a single-bodied aorto-uni-iliac stent graft used to treat an aortic aneurysm, a weakening ballooning out of the aorta. It would be implanted through a minimally-invasive endovascular procedure.

The device's encapsulated design prevents its stents from contacting the bloodstream or the vessel wall, which is designed to allow a wider range of stent graft sizes, including tapered and custom grafts.

The primary endpoint for effectiveness of the study is based on aneurysm exclusion, which will be evaluated for one year following implantation of the device.

LeMaitre previously received conditional FDA approval for its IDE supplement.

"Although we had initiated two study sites based upon conditional approval, many other hospitals, though eager to participate, have been waiting for the FDA to remove conditions … ," said George LeMaitre, the company's president/CEO and chairman in a statement. "We believe surgeons need a single-body aorto-uni-iliac stent graft to help combat aneursymal disease, and we are excited to begin implanting devices in our pivotal study."

Aaron Rees, LeMaitre's director of quality, regulatory and clinical affairs, told Medical Device Daily that the company had initiated sites at Emory University (Atlanta) and UCLA Medical Center (Los Angeles), based on conditional approval from the FDA.

The agency has allowed up to 14 centers, and the company said it plans to enroll 90 patients. LeMaitre said those patients must be followed for at least one year prior to the company's final submission to the FDA.

Aaron Grossman, a company spokesman, told MDD that LeMaitre had not disclosed publicly its timeline for submission due to the fact that "enrollment can be very difficult and challenging to predict."

The UNITE study is designed to compare the safety and efficacy of the UniFit Abdominal Stent Graft against open surgical abdominal aorta repair.

LeMaitre said that currently there are no aorto-uni-iliac endovascular stent grafts indicated for the primary treatment of aorto, aorto-illiac and/or iliac aneurysms in the United States. However, the stent is sold in the European Union and a small number of other international jurisdictions.

The FDA's IDE green light only applies to the investigational use of the UniFit Abdominal Stent Graft devices that have been sterilized with ethylene oxide gas; however, the company ultimately hopes to get approval from the FDA —using the same data from this trial — for sterilization using hydrogen peroxide.

"Ethylene oxide sterilization is sort of a tried and true sterilization method that's been accepted for a long period of time," Rees said. "Hydrogen peroxide is a newer sterilization method, and the advantage of the hydrogen peroxide is that it speeds up the process of sterilizing and verifying that the product is sterile and getting it on the shelf so that it can be shipped."

Grossman said that the hydrogen peroxide sterilization method would "deepen out competitive advantage" if the company can get the FDA "comfortable" with that method.

In April 2006, LeMaitre filed a registration statement with the SEC for an initial public offering of its common stock valued at up to $69 million (MDD, April 28, 2006)

LeMaitre manufactures both disposable and implanted devices. The company was founded in 1983 by vascular surgeon George LeMaitre, MD, who, with the help of an engineer, developed a valvulotome, a device used to prepare veins for arterial bypass.