Conor Medsystems, Inc, a developer of innovative controlled vascular drug delivery technologies, has completed enrolment of 1,700 patients in its US pivotal randomized clinical trial, COSTAR II (Cobalt chromium Stent with Antiproliferative for Restenosis). If the results of this clinical trial are favourable, the company anticipates submitting an application for marketing approval with the US Food and Drug Administration for its CoStar stent in early 2007 and potentially receiving regulatory approval in late 2007 or early 2008.

The COSTAR II trial is a randomized, single-blind, non-inferiority trial that compares the safety and efficacy of Conor's CoStar cobalt chromium paclitaxel-eluting stent with Boston Scientific's TAXUS Express paclitaxel-eluting coronary stent system in the treatment of de novo lesions in patients with single or multi-vessel coronary artery disease. This trial is being conducted in 61 US sites and 11 international sites. Patients were asymmetrically randomized between the CoStar stent and the control stent with clinical follow-up at 30 days and eight months. In addition, a 350-patient subset will undergo follow-up angiography at nine months. Conor's CoStar stent is loaded with 10 mcg of paclitaxel per 17 mm stent and incorporates a bioresorbable polymer, said the company release.

"I am very pleased that such a large study of cardiovascular disease in a 'real-world' population completed enrolment so quickly, which I believe reflects the quality of the clinical sites as well as the widespread interest in Conor's CoStar stent," said Mitchell Krucoff, M.D., FACC of Duke University Medical Center, Durham, North Carolina and a principal investigator for the COSTAR II study. "I believe the design of Conor's CoStar stent may offer several potential advantages as compared to conventional drug-eluting stents, including no surface coating, a low profile for ease of delivery and the use of a polymer that is absorbed by the body, leaving a bare metal stent. I look forward to analyzing the comparative data."

"I am delighted that we have completed enrolment in the COSTAR II trial, moving us another step closer to the US market," said Azin Parhizgar, Ph.D., Chief Operating Officer of Conor. "We believe that the proprietary design of our CoStar stent provides for optimized drug delivery and may provide advantages in treating coronary artery disease. We expect that results from this trial will be available in the first half of 2007."

The primary endpoint for the COSTAR II study is major adverse cardiac events at eight months, defined as a composite of target vessel revascularization, myocardial infarction and cardiac-related death. Other endpoints include target lesion revascularization, binary restenosis and in-segment and in-stent late loss as measured by angiography. In addition to Dr. Krucoff, Dean J. Kereiakes, M.D., FACC, Medical Director of The Heart Center of Greater Cincinnati and The Lindner Clinical Trials Center in Cincinnati, Ohio and William Wijns, M.D., Ph.D., of the Cardiovascular Center, Onze Lieve Vrouw Hospital, Aalst, Belgium are principal investigators for the COSTAR II study.

In contrast to conventional surface-coated drug-eluting stents, Conor's CoStar cobalt chromium paclitaxel-eluting stent has been specifically designed for vascular drug delivery. The CoStar stent incorporates hundreds of small holes, each acting as a reservoir into which drug-polymer compositions can be loaded. Through this reservoir design, Conor believes that it can greatly enhance control over the rate and direction of drug release and enable a wider range of drug therapies. In addition, the CoStar stent uses a bioresorbable polymer that is absorbed by the body after the drug is released, leaving no permanent polymer residues at the target site. In February 2006, Conor's CoStar stent received CE Mark approval for the treatment of coronary artery disease, and it is currently being marketed in certain countries in the European Union, Latin America and Asia through the company's distributors.

The CoStar stent is not available for sale in the United States where it is an investigational device limited by law to investigational use.