Medical Device Daily Executive Editor

The door to the second-generation of drug-eluting stent (DES) technology swung open a bit more last week with the FDA circulatory systems device panel of the FDA giving its recommendation to approve the Xience stent from Abbott Laboratories (Abbot Park, Illinois).

The panel’s thumbs up follows a similar early October vote for the Endeavor DES from Medtronic (Minneapolis) (Medical Device Daily, Oct. 10, 2007), these panel recommendations clearly boosting the chances of having two new DES devices approved in the U.S. in 2008 – though, as usual, no approval is locked up until the agency makes a final determination.

Despite what one analyst referred to as some “cranky” questions from the advisory group, the Xience provided few issues concerning efficacy as compared to first-generation DES devices, and it received a 9-1 panel vote to recommend.

However, given the current atmosphere of uncertainty and ongoing debate concerning the safety of DES devices, the panel also advised the agency to provide final approval of the Xience only with agreements from the company to perform rigorous long-term follow-up surveillances studies.

Clyde Yancy, MD, chair of the panel, referred to the company’s data indicating efficacy of the Xience, but he also termed the large majority vote by the panel as a “cautious endorsement” of the stent and that the bigger question will be the device’s safety over the long term – a question still hovering over the entire sector, both first-generation and those DES devices to come.

While recent cardiovascular conference reports have generally dismissed the view that DES devices are less safe than bare-metal stents, Yancy and other panelists frequently referred to safety issues. And Yancy indicated that the panel, despite the 9-1 vote, was generally divided on feeling that Abbott had presented enough long-term safety data.

Abbott, along with Medtronic, of course will hope for quick final approval so that they can roll out these new products in 2008, with both products expected to elbow aside the first-generation DES devices, the Cypher from Cordis (Miami Lakes, Florida), and the Taxus from Boston Scientific (Natick, Massachusetts).

Boston Scientific, though likely to see steep declines in Taxus sales, may be hurt the least since it will share the profits from Xience; Guidant had been developing this stent and when Boston Scientific acquired that company, it had to divest the stent to Abbott, but it retained the right to sell the same device as the Promus under a private-label arrangement.

Boston Scientific thus issued a statement welcoming the panel vote, saying that FDA approval would make it the first company to have two DES products in the U.S.

Hank Kucheman, senior VP and president of Boston Scientific’s cardiovascular business, in a statement, said, “Once approved in the United States, the Promus stent system – together with our proven and market-leading TAXUS stent technology – will enable Boston Scientific to offer physicians and their patients a choice of two distinct drugs, each on a highly deliverable stent platform.”

The panel approvals put Endeavor and Xience at the starting gate, and the race is now on to see which wins first approval, largest uptake and ultimate market laurels.

Overall, Medtronic’s Xience appears to be the favorite, having gotten the early panel okay, and at least one analyst – Michael Weinsten of JPMorgan — predicted earlier this year at the company’s annual conference that Endeavor will immediately capture 20% of the DES market “out of the gate.”

Abbott provided data for more than 400 patients in the category of long-term usage of the Xience, with those patients implanted for at least two years. But that was not considered long enough, or representing enough patients, by some panelists.

Panel member John Somber, MD, professor of pharmacology at Rush University Medical Center (Chicago), said “one-to-two-year data” was not adequate. And Somberg cast the lone dissenting vote against Xience approval.

Medtronic had provided about three times as much data for the Endeavor concerning patients followed for more than two years. Thus, the final, seemingly overwhelming vote by the panel to recommend Xience appeared primarily efficacy-based.

Wachovia Capital Markets device analyst Larry Biegelsen, in a note, said he foresees FDA approval of Xience as early as the second quarter of ’08, though “the FDA could decide to wait until the data becomes available in mid-2008, given the intense scrutiny of the safety of DES.”

He said that his analysis puts Xience as the market leader for DES with a 55% share in the U.S.

Bear Stearns analyst Rick Wise echoed the concerns that the FDA may wait until 2Q08 to see full two-year data on the Xience and so he predicted FDA approval and market launch in the third quarter of ’08.

In his note, he said, “We felt the overall tone of the FDA during their afternoon presentation was positive for Xience. The FDA supported [Abbott’s] pooling of SPIRIT II & III [trial] data to increase the sample size in order to better analyze rare events like late stent thrombosis despite some pushback from the panel. Also, the FDA’s statistical analysis showed that across the SPIRIT family of clinical trials Xience generally showed non-inferiority vs. Taxus even in a worst case analysis.”