Reva Medical Regaining Ground in Development of Next-Generation Stent

5/5/09

In the race to develop a fully dissolvable cardiac stent, San Diego’s Reva Medical is clearly second. And to CEO Robert Shultz, that’s a good place to be, especially for a startup that had to restart development of its stent technology.

The cost of establishing a big new market, Shultz says, is better left to the drug and medical device giant Abbott Laboratories, which is on pace to launch its dissolvable stent nine months to a year ahead of Reva. “The important thing is to be in the race, not who is one or two,” Shultz told me when I caught up with him by phone to discuss the company’s plans.

Dissolvable, or bioabsorbale, stents are seen as the next big thing in cardiac care. They represent an advance over metal stents — tiny mesh tubes that are used to prop open previously clogged arteries. Some existing stents are coated with drugs to prevent a build up of scar tissue, a complication that can cause the blood vessel to become re-blocked. But drug-coated stents slow the healing process and carry a higher risk of blood clots that also can block the vessel.

Reva and others are betting that dissolvable stents can avoid these complications, and research in the Lancet in March suggests they may be right. As Abbott reported, the 30-patient study found that Abbott’s corn-derived stent was safe after two years. There were no cases of blood clots forming inside the stents and the stents were fully absorbed. “Abbott made a lot of progress and we want that to occur,” Shultz said. “They helped everybody by demonstrating the stents are safe.”

Shultz believes Reva’s stent has several advantages. When the stent is implanted, a series of stent elements slide open and lock into place, a unique design that helps the stent retain its shape inside the vessel. And because the stent contains iodine — unlike the Abbott stent — it is completely visible using X-ray fluoroscopy, a common form of clinical imaging, he said. Physicians like to see where the stent is placed, Shultz said. “The ability to see it in the cath lab – this is going to be important from a commercial perspective,” he said.

Still, the Reva stent is a work in progress. The stent, which was not drug-coated, did not perform as well as hoped in a small 2007 trial, resulting in repeat procedures for patients. “There were too many revascularizations,” Shultz said, adding the company has learned from the trial and has made changes to avoid continued problems.

The market for new stents is potentially huge. Currently, metal coronary stents are used in patients with arteries that are more than 50 percent blocked – a $5.5 billion a year market worldwide. Shultz thinks the total stent market could grow to $10 billion a year as bioabsorbale stents clear the way for people with vulnerable plaque to be treated. His reasoning: doctors won’t use a permanent metal stent in patients whose arteries are not yet blocked, but they may be willing to try a temporary, bioabsorbable one. “Potentially, it is a large, large market,” he said.

Reva was founded in 1998 to develop a metal stent using the slide and lock technology. But the market shifted to drug-coated stents, causing Reva to scrap its metal stent program. By the end of 2003, it had slashed its workforce to 16 from 50.

Earlier that year, the company set its sights on developing a bioabsorbable device and licensed the polymer technology from Rutgers University. The tyrosine-derived polymer breaks down into water, carbon dioxide and ethanol, according to a published review.

Near the end of 2004, Reva formed a partnership with Boston Scientific, an important player in the stent market. In return for an undisclosed equity investment, Boston Scientific received rights to the technology and an option to acquire REVA.

Terms were renegotiated in 2007 to remove Boston Scientific’s option on the company, a change that made it easier for Reva to attract fresh investment, Shultz said. The company received $42 million that year from a group led by Cerebus Capital of New York and Brookside Capital, an affiliate of Bain Capital based in Boston. It ranked as the second-largest venture financing of a medical device company in 2007, Shultz said.

Reva now has 44 employees, so its staffing is approaching previous levels. And it has money to complete human studies expected to begin next year that could lead to approval of the stent in Europe, Shultz said. Details of the clinical trial haven’t been determined, but it will likely include 300 to 500 patients and take two years. Abbott expects to have its European approval in 2012. So the race is on.

Denise Gellene is a former Los Angeles Times science writer and regular contributor to Xconomy. You can reach her at dgellene@xconomy.com Follow @

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  • http://www.mediligence.com/rpt/rpt-c245.htm Patrick Driscoll

    Bioabsorbable or dissolvable stents offer a compelling alternative to drug-eluting stents, maintaining vessel patency following revascularization and minimizing the risk of late stage thrombosis. Reva’s stents are part of the worldwide coronary stents market analysis described at http://www.mediligence.com/rpt/rpt-c245.htm.