PERSEUS Trial Results Presented for Boston Scientific's Taxus Element Stent System

March 15, 2010— Boston Scientific Corporation (Natick, MA) announced 12-month results from its PERSEUS clinical program that demonstrated positive safety and efficacy outcomes in workhorse lesions for the platinum chromium Taxus Element paclitaxel-eluting stent system compared to the Taxus Express² paclitaxel-eluting stent system. The results also showed a similar safety profile and statistically superior efficacy outcomes in small vessels for the Taxus Element stent compared to a historical control group of patients receiving the company's Express bare-metal stent. Dean Kereiakes, MD, who is principal investigator for the PERSEUS clinical program, presented the analysis of the data at the American College of Cardiology's 59th annual scientific sessions in Atlanta, Georgia.

The PERSEUS clinical program compares the Taxus Element stent to previous generation stents in more than 1,600 patients in two parallel trials at 90 centers worldwide.  Clinical data from the PERSEUS trials will support regulatory approval of the Taxus Element paclitaxel-eluting stent system in Europe, the United States, and Japan.

The pivotal PERSEUS Workhorse trial is evaluating the safety and efficacy of the Taxus Element stent compared to Boston Scientific's first-generation Taxus Express stent in 1,262 patients with de novo lesions. The prospective, randomized (3:1) trial met its primary endpoint of noninferiority for target lesion failure at 12 months with rates of 5.6% for the Taxus Element stent and 6.1% for the Taxus Express stent. The secondary endpoint of in-segment percent diameter stenosis at 9 months as measured by quantitative coronary angiography was also met.

The PERSEUS Workhorse results also demonstrated similar safety for the Taxus Element stent as demonstrated by low rates of major adverse cardiac events (MACE) and stent thrombosis. All components of MACE, including cardiac death, myocardial infarction (MI), and target vessel revascularization were similar to the Taxus Express stent control. A numerically lower rate of non–Q-wave MI for the Taxus Element stent resulted in lower overall MI (2.2% vs 2.9%; P = .48). Stent thrombosis rates using the Academic Research Coalition definition of definite/probable were statistically similar for the Taxus Element and the Taxus Express stents (0.4% and 0.3%; P > .99).

Boston Scientific stated that results were also presented from the PERSEUS Small Vessel trial, a single-arm study that compares the Taxus Element stent in 224 patients with small vessels (> 2.25 to < 2.75 mm in diameter and < 20 mm in length) to a matched historical control group of 125 patients treated with the Express bare-metal stent. The trial met its primary endpoint of superiority for in-stent late loss at 9 months with unadjusted values of 0.38 mm for the Taxus Element stent and 0.8 mm for the Express stent (P < .001). The trial also met its secondary endpoint of superiority for target lesion failure at 12 months, showing a statistically significant reduction with an unadjusted rate of 7.3% for the Taxus Element stent compared to a prespecified performance goal of 19.5% (P < .001) based on historical outcomes for the control stent. The propensity-adjusted MACE rates were significantly lower for the Taxus Element stent compared to the bare-metal control stent (10.5% vs 30.4%; P = .002). Stent thrombosis rates using the Academic Research Coalition definition of definite/probable were comparable for the Taxus Element stent and Express stent (0.3% vs 0.6%; P = .65).

Boston Scientific received CE Mark approval for the Promus Element stent system in October 2009 and expects CE Mark approval for the Taxus Element stent system in the second quarter of this year. In the United States, the company expects approval from the US Food and Drug Administration for the Taxus Element stent system in the middle of next year and for the Promus Element stent system in the middle of 2012. In Japan, the company expects approval for the Taxus Element stent sin late 2011 or early 2012 and for the Promus Element stent system in the middle of 2012. The Taxus Element stent and the Promus Element stent are investigational devices in the United States and are limited to investigational use only, the company advised.