Cook Medical Moves to Take Lead in Esophageal-Stent Market

Cook Medical hopes to retake leadership of the gastroenterology stent market from Boston Scientific with its new line of Evolution stents.

The Evolution Esophageal self-expanding stent entered the European market in February and earned a 510(k) from the FDA in June. About 700 of the devices have been used so far worldwide. The privately held Indiana company says it expects to begin rolling out the Evolution Colonic and Evolution Duodenal stents in Europe by the end of summer and in the United States by the end of 2008.

The Evolution line gives Cook “access to a $200 million market that we’re not really present in at the moment,” Barry Slowey, vice president of global sales and marketing for Cook’s endoscopy division told The Gray Sheet in an interview.

“What we’re trying to take advantage of is that Boston Scientific isn’t very focused on gastroenterology [right now] – they’re very focused on cardiology – so we haven’t seen a lot of innovation or a lot of spending in the [gastrointestinal (GI)] space,” Slowey said. “So we’re trying to take advantage of that opportunity to be very creative and innovative in the GI market, and one of the biggest opportunities we see at the moment is in GI stenting.”

Esophageal stents are implanted to improve the quality of life of patients with an esophageal tumor that makes it difficult for them to swallow. About 16,000 new cases of esophageal cancer are found annually in the United States – with the number of cases growing about 8%-10% each year – and about 11,000 esophageal stents are placed in those patients annually, according to Cook. The alternative for most patients is to eat through a feeding tube.

Cook Decides To Challenge Boston Scientific

Cook pioneered esophageal stents in the mid-1980s, but Boston Scientific has led the esophageal stent market since it acquired the former market leader Schneider from Pfizer in 1998.

Boston Scientific currently markets the self-expanding Ultraflex esophageal stent, introduced in 1994, and Polyflex self-expanding esophageal stent, acquired when the firm bought Rusch in 2005.

“I think that what happened with Boston is that once they purchased [Schneider], they became dominant and they didn’t focus on this area from an innovation perspective, and that gives us the opportunity to come in with some very innovative technology,” Slowey said.

While Boston Scientific took command of the GI stenting market, Cook’s endoscopy division was busy focusing on the biliary intervention market and its Zilver biliary stent and was paying less attention to GI stents.

About five years ago, Cook realized it would need a better range of GI intervention products in order to become competitive with Boston Scientific. “We needed to come to market with breakthrough technology in GI stenting that would position us differently than our competition,” Slowey said.

Cook Answers Doctors’ Call For More Control

Cook assembled an advisory panel of experts and conducted extensive market research to understand how esophageal stent designs could be improved.

“The general feedback we got was that there hasn’t been a huge amount of innovation in this market,” Slowey recalled. “People were saying that the stents have performed reasonably well, but there were a number of problems they felt hadn’t been overcome and a number of things they’d like to see improved.”

Among the biggest complaints gastroenterologists had about the existing esophageal stent systems was that patients treated with the stents often needed a second intervention after the first stent became impacted with food or the tumor grew into the lumen of the stent.

Evolution is the first esophageal stent with an internal and external silicone coating – similar to the material in Cook’s enteral feeding tubes – designed to resist tumor ingrowth into the stent and allow the patient to swallow normally. Unlike the polyurethane coatings on many esophageal stents, Evolution’s silicone coating does not disintegrate in the acidic environment of the esophagus.

Also, about 10% or 15% of esophageal stents migrate into the stomach shortly after being implanted, according to Cook. To reduce this risk, Evolution has uncoated flanges on both ends, resulting in a “dumbbell or dogbone shape,” whereas most esophageal stents have a flange only on the distal end. The flanges are uncoated to allow the mucosa lining of the esophagus to grow around the sent struts and secure the stent in place, Cook says.

Physicians do not have direct visualization of the stented area while implanting the esophageal stent, and instead must rely on fluoroscopy to estimate the size and location of the stricture needing to be covered by the stent. A stent positioned too high may fail to fully cover the esophageal stricture, and one positioned too low is at high risk for migration into the stomach.

Boston Scientific’s Ultraflex is deployed by releasing a suture wrapped around the stent. Once the stent begins to expand, the physician cannot adjust its position, Slowey explained.

Cook’s market research showed that “the physicians want very controlled release of the stents, rather then starting off and then not having a way to control the rate at which the stent deploys.”

To give the physician more control over the stent placement, Evolution’s deployment system has a pistol-grip mechanism. Each time the physician pulls the trigger, only an 8 mm segment of the stent opens up. The stents are 8 cm to 15 cm in length.

Evolution is also the only esophageal stent system that allows the physician to reverse the deployment. The physician can retract the stent 8 mm at a time and even retract the whole stent and start the procedure over.

Cook is pricing Evolution at or slightly below the Ultraflex – around $2,000 per stent – to establish “cost-value leadership,” Slowey said. “What we wanted was a rapid uptake of this new technology, and we didn’t want price to be a hurdle.”

The Evolution Colonic and Evolution Duodenal stents feature a deployment system similar to the esophageal system’s, but are more flexible and are uncoated. They will also have a Flexor introducer sheath similar to the sheath on Cook’s abdominal aortic aneurysm stent grafts, Slowey said.

SOURCE: The Gray Sheet