November 29, 2007 -- Gaithersburg, Maryland -- The FDA Circulatory System Devices Advisory Panel, which met today to hear data and opinions from the manufacturer, as well as outside experts, on the safety and efficacy of Abbott's XIENCE V Drug-Eluting Stent, has voted 9-to-1 to recommend approval. The FDA is not required to follow the Panel's recommendation, but usually does.

The single dissenting vote came from Dr. John C. Somberg, a professor of Clinical Pharmacology at Rush University Medical Center, who had previously expressed concern that Abbott's clinical trials had not yet provided sufficient safety assurance for the period beyond 12 months. The issue of late stent thrombosis, or blood clots forming more than 12 months after stent implantation, surfaced last year around the previously-approved drug-eluting stents: the CYPHER, made by Cordis / Johnson & Johnson, and the TAXUS, from Boston Scientific. The safety issue became paramount and was the subject of a much-reported on two-day meeting of this same FDA Panel on December 7-8, 2006, so the Panel members were already quite sensitive to these concerns.

Post-Market Follow-up Required -- No Delay Seen
The Panel recommended approval, based to a great extent on Abbott's promise to do a long-term post-market follow-up to track the safety. Some financial analysts expressed concern that the time needed for Abbott to design this longer term follow-up study might delay approval of the XIENCE. However, Abbott currently has several larger XIENCE studies in process and recently announced the hiring of Dr. Charles Simonton as Chief Medical Officer for the cardiac group at Abbott Vascular. While at the Carolinas Heart Institute in North Carolina, Dr. Simonton headed up the STENT Registry, currently one of the largest data sets of stent patients which has regularly issued long-term follow-up reports since its inception 4 years ago. His expertise and experience, along with clear indications that the FDA was going to require all stent manufacturers to include much larger and longer term post-market studies than the Agency had in the past, would indicate that Abbott already is far along in designing such a study, and this should not represent a significant delay.

"Stent Wars" Expand
For the past 3-4 years, the U.S. drug-eluting stent market has been under the sole purview of the CYPHER and TAXUS stents, both of them first generation devices. Last month Medtronic's Endeavor received unanimous FDA Panel approval -- along with today's vote, there may soon be four stents in the U.S. market, with two of them being newer designs. According to many cardiologists, these new DES are based on a more advanced and better-performing stent platform. Prior to the introduction of drug-eluting stents, Abbott's (formerly Guidant's) Multi-Link and Medtronic's Driver bare metal stents, were thinner, stronger, more deliverable and showed a lower restenosis rate than other bare metal stents. Additionally, both manufacturers claim to have developed more biocompatible coatings.

The safety profile of Medtronic's new stent has been borne out in large studies, with some data going out to five years. Abbott's XIENCE V, while it doesn't have as large a data set, has shown significantly improved results and in a recent study, demonstrated a 43% reduction in MACE (Major Adverse Cardiac Events, such as heart attacks, death, re-intervention) over its chief rival, Boston Scientific's TAXUS.

The size of the drug-eluting stent market worldwide has shrunk considerably over the past year, as safety concerns drove a switch back to bare metal stents and as other studies even questioned the need for some stent procedures. However, most observers of the interventional cardiology scene agree that, if approved, Medtronic and Abbott will be taking major market share from Cordis and Boston Scientific -- although Boston, as part of its acquisition agreement with Guidant, has the right to sell Abbott's XIENCE under its own brand name PROMUS, so it will in effect share in the fruits of its own flagship stent's demise.

Angioplasty.Org Home •  PatientCenter

send comments & suggestions to "info at angioplasty dot org"
read Terms of Use and Privacy statement

Angioplasty.org is an independent educational health site
which receives support from
Toshiba America Medical Systems, Volcano Corporation, Terumo Medical Corporation
Cardium Therapeutics, Inc. and Lenox Hill Heart and Vascular Institute of NY
All content, including text, photos and video
© Copyright Venture Digital LLC 1996-2008