Medtronic Presents ENDEAVOR IV Safety and Efficacy Data

September 21, 2009—At the Transcatheter Cardiovascular Therapeutics (TCT) 2009 scientific symposium in San Francisco, Medtronic, Inc. (Minneapolis, MN) announced the latest findings from the ENDEAVOR IV clinical trial, a large study comparing Medtronic's Endeavor zotarolimus-eluting stent and the Taxus paclitaxel-eluting stent (Boston Scientific Corporation, Natick, MA). At 3 years, the patient follow-up data demonstrate statistically and clinically significant differences in measures of safety between Endeavor and Taxus. The new data also show no difference in efficacy between the two devices at 3 years. Martin B. Leon, MD, and David Kandzari, MD, are the principal investigators for ENDEAVOR IV. The data were presented during The Drug-Eluting Stent Summit Part 1 at the TCT conference.

According to the company, ENDEAVOR IV enrolled 1,548 patients, equally randomized to receive an Endeavor or Taxus drug-eluting stent (DES). The primary endpoint in the study was noninferiority at 9 months on the measure of target vessel failure (TVF), a composite of cardiac death, myocardial infarction (MI), and target vessel revascularization.

According to Dr. Leon, for several years there has been a trend toward outstanding safety with the Endeavor stent throughout the clinical program and in pooled analyses. These latest randomized data are the first to show statistically significant differences on hard clinical endpoints that clearly favor one DES over another at 3 years. Specifically, they show comparable efficacy between the Endeavor and Taxus stents in long-term follow-up, with significant safety advantages for Endeavor patients with regard to a reduction in large MIs that are directly attributable to the significantly higher rate of very late stent thrombosis observed with the Taxus stent.

The company stated that concerns about the consequences of the higher observed rate of very late (> 1 year) stent clotting in DES versus bare-metal stents have loomed since 2006 but have been allayed by large, population-based registry data that have not shown an increase in death or MI. Endeavor IV represents a long-term, large, head-to-head DES comparison to demonstrate a statistically significant increase in very late stent clotting and a corresponding significant increase in cardiac death and MI. The Endeavor IV data definitively show that at 3 years of follow-up, patients treated with an Endeavor stent have a statistically and clinically significant 48% (P = .004) lower risk of heart attack or cardiac death than patients treated with a Taxus stent, and a 91% (P = .004) reduction in the risk of very late stent thrombosis.