CDU Washington Writer

WASHINGTON – Stents were the talk of the town at last month’s Transcatheter Cardiovascular Therapeutics (TCT) conference, and a relatively young company was looking to generate a bit of a buzz with its unique twist on the devices.

Almost from the opening hours of TCT, the annual interventional vascular therapy conference that drew about 12,000 attendees to the Washington Convention Center this year, technology from Xtent (Menlo Park, California) was turning heads. Its customizable drug-eluting stents, whose size can be manipulated in 4 mm segments during implantation, were featured in a live-case session on the first morning of the conference, and later that day the platform was featured in a discussion of future technologies expected to soon impact the sector.

“This is, in essence, our coming out,” Greg Casciaro, Xtent’s president and CEO, told Cardiovascular Device Update. “Once our stents are deployed, at whatever length a physician deems appropriate to cover a lesion, you cannot discern it from another off-the-shelf stent. So it looks just like everything else, and yet it has the ability to be customized in length and diameter, and can be delivered in places where anything else could get to today, and then some.”

The stents’ clinical debut was featured prominently courtesy of a diagnostic broadcast aired during TCT’s initial breakfast session. The procedure, conducted four months after implantation, showed images of “a very beautiful follow-up,” said Eberhard Grube, MD, of Heart Center Siegburg (Siegburg, Germany), the principal investigator in Xtent’s initial human study that began over the summer. “This is a very nice angiographic result.”

The images were made by intravascular ultrasound and optical coherence tomography. The trial, called CUSTOM I, enrolled 30 patients and tested 36 mm stents. Four-month angiographic reviews of their performance in the first 10 patients have been conducted to date, and all appeared as successful as that presented by Grube. The remaining 20 patients will have their follow-up evaluation at eight months, and all 30 patients in the study will receive one-year follow-up.

The stents, which bear the same name as the company, are covered with a drug called biolimus-A9 through a resorbable polylactic acid coating. The drug and accompanying coating employed in the Xtent system are non-exclusively licensed from Biosensors (Newport Beach, California), and Casciaro is confident in their efficacy, especially in light of the early successes demonstrated in CUSTOM I.

But he and others are equally excited about the platform’s distinguishing customizable feature, which potentially eliminates the need for a closet full of varying stent sizes. These days, the average stent length is 20 mm.

In situ customization also simplifies catheterization lab administration. “We believe that it will no longer be necessary to maintain the several dozen different stent size/length combinations in inventory that most cath labs now must,” said Casciaro. “[That] offers the potential for significantly improved hospital efficiencies.”

The Xtent system also includes a marker component, which could help practitioners avoid the use of excessive dye for imaging lesions to discern an appropriate stent length, and also avoid overlapping stents.

“Instead, they simply go beyond the disease, where the vessel is normal, and then start paving out the amount of stent they want coming back at them,” Casciaro said of placing an Xtent stent into a patient. “So they cover an entire disease area without having to worry about what the length of that lesion is ahead of time.”

That ability to tailor, said Brian Walsh, the company’s vice president of sales and marketing, “eliminates guesswork and geographic miss, improving accuracy in stent treatment.” He noted that imprecision is a recognized problem, causing longitudinal geographic misses about 45% of the time, according to a 1,500-patient study called STLLR.

Walsh also pointed to another added benefit provided by the Xtent system: multi-lesion stenting with a single catheter, which clearly could simplify multi-lesion procedures, which account for nearly 70% of current drug-eluting stent usage.

“What we bring is a uniqueness, this characteristic of customization, to an environment that will probably generate actual revenues just for two companies of $6 billion over the next year,” Casciaro said. “If we were coming out with a ‘me too’ product, we couldn’t [compete]. We don’t have the infrastructure or the deep pockets they do, but we’re a very well-funded, early stage medical device/drug provider. And what gets us in the game is our platform.”

Such flexibility prompted others at the TCT meeting to endorse the Xtent’s promise. Martin Leon, MD, of New York Presbyterian Hospital/Columbia University Medical Center (New York) and head of the TCT-sponsoring Cardiovascular Research Foundation (also New York), noted that the system “has some cost and practicality benefits.”

Later, Peter Fitzgerald, MD, PhD, of Stanford University (Palo Alto, California), said in a forward-looking discussion that Xtent represents one of several platforms would “contribute to the lineage of drug-eluting stent technology.”

Final CUSTOM I data are due early next year, and Casciaro said the company is soon to begin a follow-up trial called CUSTOM II. It will test stents up to 60 mm in length for multiple lesions in multiple vessels in 70 patients overseas. In the short term, the 100-patient database from the CUSTOM studies could provide the basis for approval in Europe, and fulfill requirements to open an investigational device exemption in the U.S. After that, a larger trial to likely include more than a thousand patients would be needed prior to FDA clearance.

Casciaro said the 60-employee company, which has raised $45 million to date through three rounds of venture capital investments, would need to raise additional funds to finance any commercialization efforts and large-scale trials. The three-year-old firm has four U.S. patents protecting its platform, as well as more than 30 pending applications for further intellectual property protection.

The company originated in The Foundry, a widely recognized medical device incubator, and is funded by such well-known med-tech investors as Advanced Technology Ventures, Latterell Venture Partners, Morgenthaler Ventures and Split Rock Partners.

Going forward, Casciaro said he envisions a couple of future scenarios for Xtent: the company could raise that added funding and more and provide direct competition to the two currently marketed drug-eluting stents, or the platform could provide an entr e for another company to get into this enticing market.

“But frankly, we are not shopping ourselves,” he said. “We have to allow the clinical outcomes to speak for us. Once that takes place, and it already is with CUSTOM I, then we’re off to the races.”