Medtronic Starts U.S. And International Trials Of Endeavor(R) Resolute Drug-Eluting Coronary Stent
Consistent with its commitment to advancing the treatment of cardiovascular disease through innovative product design and rigorous clinical research, Medtronic, Inc. (NYSE: MDT), announced today the start of two new trials of the Endeavor® Resolute drug-eluting stent (DES), the company's innovative complement to the Endeavor drug-eluting stent, which was approved by the U.S. Food and Drug Administration (FDA) in February 2008.
Clinical research teams led by interventional cardiologists Dr. James Carr at East Texas Medical Center in the United States and Prof. Dr. Franz-Josef Neumann at the Heart Center of Bad Krozingen in Germany enrolled the first patients in RESOLUTE US (R-US) and RESOLUTE International (R-Int), respectively. The Endeavor Resolute zotarolimus-eluting coronary stent system is an investigational product in the United States, where it is limited to investigational use only under an IDE (investigational device exemption) granted by the FDA. The device received the Conformité Européène (CE) mark in September 2007 and is commercially available in more than 100 countries around the world.
Exemplifying a focus on patient safety, Medtronic's drug-eluting stents use highly biocompatible polymers. The Endeavor Resolute DES uses the proprietary BioLinx™ polymer, which was designed to meet the same biocompatibility requirements as the phosphorylcholine (PC) polymer used in Medtronic's flagship Endeavor stent. Compared to the PC polymer, the BioLinx polymer is designed to extend the duration of drug exposure in the vessel - an elution profile of potential relevance to patients that physicians consider to be at high risk of needing a repeat procedure. Developed by Medtronic scientists, it is the first polymer created specifically for use on a drug-eluting stent. Extensive preclinical studies have established both polymers' biocompatibility and drug-delivery capabilities.
Stent Portfolio Addresses Spectrum of Clinical Need
Medtronic's broad portfolio of coronary stents provides physicians with a variety of stent choices to address the spectrum of clinical needs. The portfolio includes the Endeavor and Endeavor Resolute drug-eluting stents and the Driver and MicroDriver bare-metal stents. All of Medtronic's coronary stents share the same cobalt alloy platform, which features a unique modular architecture and custom laser fusion patterns that together provide excellent radial strength and conformability to the vessel wall. Both of the company's drug-eluting stents use the potent antiproliferative, noncytotoxic drug zotarolimus.
"Different patients require different treatment strategies, which is why the Endeavor Resolute stent and the RESOLUTE clinical program are so important for the future of interventional cardiology," explained Dr. Martin Leon, associate director of the Cardiac Catheterization Laboratory at Columbia University Medical Center in New York, and one of three coordinating investigators for R-US. "These newly initiated trials have the potential to contribut significantly to the growing body of evidence that characterizes the safety and efficacy of the Endeavor Resolute DES."
Dr. Petr Widimský, professor of medicine and cardiology at the Faculty Hospital of Kralovske Vinohrady in Prague, and one of three principal investigators for R-Int, added, "In many countries outside the United States, the Endeavor Resolute DES already provides an important option for the minimally-invasive treatment of coronary artery disease. The significant scale and scope of these multicenter registries will add to our understanding of how to use this new stent in standard clinical practice for the benefit of our wide range of patients."
Latest Trials Follow New FDA Guidance
R-US and R-Int are among the first clinical trials to follow new FDA guidance on drug-eluting stent research announced in March. They are part of the RESOLUTE clinical program, which includes:
- RESOLUTE - The first clinical trial of the Endeavor Resolute DES, this single-arm study enrolled 139 patients at 12 investigational sites in Australia and New Zealand. Initiated in December 2005, enrollment concluded in October 2006. RESOLUTE met its primary endpoint, in-stent late lumen loss assessed at nine months post-procedure; two-year results will be released in October at Transcatheter Cardiovascular Therapeutics (TCT) 2008 in Washington, D.C.
- RESOLUTE All-Comers - This trial will randomize approximately 2,300 patients, in a one-to-one manner, to the Endeavor Resolute or Abbott Laboratories' Xience® DES at 15-20 international medical centers in countries where both stents are commercially available. Patients seen in routine clinical practice are eligible for enrollment - the meaning of "All-Comers." The primary endpoint for the trial is target lesion failure (TLF) - defined by the FDA as cardiac death, target vessel myocardial infarction (Q-wave or non-Q-wave), or clinically-driven target lesion revascularization (TLR) by percutaneous or surgical methods - at one year post-procedure. RESOLUTE All-Comers (R-AC) began enrolling patients in April 2008; enrollment currently stands at more than 1,200 patients, approximately 50 percent of the total.
- RESOLUTE US - This prospective, multicenter, controlled trial is designed to assess the safety and efficacy of the Endeavor Resolute DES for the treatment of de novo lesions in native coronary arteries with reference vessel diameters of 2.25 mm to 4.2 mm and lesion lengths less than or equal to 27 mm that are amenable to percutaneous treatment with a stent. One of the trial's primary endpoints is TLF at 12 months post-procedure. RESOLUTE US (R-US) will enroll 1,399 patients at up to 125 investigational sites in the United States and use historical data from other Medtronic stent studies as a control; enrollment began in August 2008. All patients will be followed for five years. Data from R-US will be used to seek FDA approval of the Endeavor Resolute stent.
- RESOLUTE International - This prospective, multicenter registry will evaluate the Endeavor Resolute DES in a "real-world" patient population, meaning that (similar to RESOLUTE All-Comers) patients seen in routine clinical practice are eligible for enrollment. RESOLUTE International (R-Int) will enroll up to 2,200 patients at approximately 100 centers worldwide (except the United States and Japan) where the Endeavor Resolute DES is commercially available; enrollment began in August 2008. The primary endpoint is a composite of cardiac death and myocardial infarction (not clearly attributable to a nontarget vessel) at one year post-procedure.
RESOLUTE Tested Stent in "Complex, Challenging" Lesions
The initial feasibility trial of the Endeavor Resolute DES, RESOLUTE enrolled a significant number of patients whom the principal investigator, Prof. Ian Meredith of Monash Medical Centre in Melbourne, Australia, characterized as presenting "with especially complex and challenging characteristics." Average lesion length was 15.5 mm, and 82 percent of the patients were classified as having complex (B2/C) lesions.
Patients treated with the Endeavor Resolute stent in RESOLUTE required no repeat procedures through nine months post-procedure and had experienced no protocol-defined stent thrombosis through 12 months of follow-up. In-stent late lumen loss at nine months, the study's primary endpoint, was met at 0.22 mm ± 0.27 mm. Among the trial's 139 patients, only one required clinically-driven TLR or target vessel revascularization (TVR) through 12 months post-procedure. At the same timepoint, the incidence of major adverse cardiac events (MACE) was 8.7 percent.
"Endeavor Resolute continues to deliver impressive clinical outcomes," Prof. Meredith said before the one-year results from RESOLUTE were released at TCT 2007. "The stent has successfully reduced restenosis in a particularly challenging patient group while maintaining its safety profile."
Medtronic, Inc., headquartered in Minneapolis, is the global leader in medical technology - alleviating pain, restoring health and extending life for millions of people around the world.