Pooled Data Support Boston Scientific's Ion PtCr Stent System

April 3, 2011—Boston Scientific Corporation (Natick, MA) announced results from a pooled patient-level analysis of its PERSEUS (PERSEUS Workhorse and PERSEUS Small Vessel) and TAXUS ATLAS clinical trial data, demonstrating favorable safety and efficacy outcomes of the company's next-generation Ion platinum chromium (PtCr) paclitaxel-eluting stent system (Taxus Element) compared to the currently available Taxus Liberté paclitaxel-eluting stent system. Dean J. Kereiakes, MD, principal investigator for the PERSEUS clinical program, presented the results at the American College of Cardiology's (ACC) 60^th annual scientific session.

Boston Scientific stated that the Taxus Element stent system, which received CE Mark approval in May 2010 for the European market, will be commercialized in the United States as the Ion paclitaxel-eluting PtCr coronary stent system, which it expects to launch by mid-2011. In the United States, the Ion stent system is currently limited to investigational use only and not available for sale, the company advised.

“Although the Ion and Taxus Liberté stents employ the same drug and polymer, the Ion stent demonstrated significantly lower rates of major adverse cardiac events (MACE), target lesion failure (TLF), and myocardial infarction (MI) in this case-matched analysis of nearly 2,300 patients,” commented Dr. Kereiakes. “This study demonstrates that alloy composition, stent design, and strut thickness may influence angiographic and clinical outcomes following drug-eluting stent deployment.”

According to Boston Scientific, the study compared pooled patient-level data from 2,298 patients enrolled in the PERSEUS (Ion stent) and TAXUS ATLAS (Taxus Liberté stent) trials. Propensity score matching was performed to adjust for differences in patient and lesion characteristics between the groups, and clinical follow-up was conducted out to 12 months. Propensity-matched results in 1,326 patients revealed that the Ion stent achieved significantly lower rates of MACE (7.5% vs 12%; P = .007) and TLF (5.5% vs 8.5%; P = .04) largely driven by a reduction in MI (1.8% vs 3.9%; P = .02). A numerically lower but not statistically different rate of target vessel revascularization was also observed in favor of the Ion stent (6.5% vs 8.8%; P = .12), supported by significantly lower late loss at 9 months (0.33 ± 0.52 mm vs 0.42 ± 0.56 mm; P = .04).

The PERSEUS clinical program compared the Ion (Taxus Element) stent to previous-generation Boston Scientific stents in more than 1,600 patients in two parallel trials at 90 centers worldwide. The PERSEUS Workhorse trial reported 12-month results at the ACC annual meeting in March 2010, showing positive safety and efficacy outcomes in workhorse lesions for the Ion stent system compared to the Taxus Express² stent system. The presentation was previously summarized in Cardiac Interventions Today.

The TAXUS ATLAS program compared patients with de novo coronary lesions treated with the Taxus Liberté stent to a historical case-matched Taxus Express stent control group. The 5-year ATLAS data were presented in September 2010 at the Transcatheter Cardiovascular Therapeutics scientific symposium, as reported in Cardiac Interventions Today.