Nine-Month PLATINUM QCA Data Presented for Boston Scientific's Promus Element

September 21, 2010—Boston Scientific Corporation (Natick, MA) announced that data from its PLATINUM QCA study were presented by Principal Investigator Ian T. Meredith, MD, at the Transcatheter Cardiovascular Therapeutics scientific symposium in Washington, DC. PLATINUM QCA is designed to evaluate the company's Promus Element everolimus-eluting platinum chromium coronary stent. The results provided 30-day and 9-month clinical outcomes and 9-month quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) data supporting the safety and efficacy of the Promus Element stent.

According to Boston Scientific, PLATINUM QCA is one of five multicenter studies in the PLATINUM clinical program, which is evaluating the safety and efficacy of the Promus Element stent, totaling more than 1,800 patients. This includes a randomized controlled trial for workhorse lesions, as well as single-arm studies evaluating small vessels, long lesions, and pharmacokinetics. The prospective, single-arm PLATINUM QCA study enrolled 100 patients at 14 sites.

In the study, the Promus Element was compared to Boston Scientific's Promus stent, which is a private-labeled Xience V everolimus-eluting coronary stent system manufactured by Abbott Vascular (Santa Clara, CA) and distributed by Boston Scientific. The Promus (Xience V) device was evaluated in Abbott Vascular's SPIRIT clinical program.

Professor Meredith reported that the PLATINUM QCA primary endpoint of 30-day composite cardiac events was 1%, which included cardiac death (0%), myocardial infarction (0%), target lesion revascularization (TLR, 1%), and stent thrombosis (Academic Research Consortium definite/probable, 1%). Of the 100 patients studied, one patient experienced a periprocedural stent thrombosis and TLR. No additional major clinical events were reported from 31 days to 9 months.

The study also met its prespecified efficacy endpoint of in-stent late loss in workhorse lesions at 9 months as measured by QCA compared to historical Taxus Express stent data. The Promus Element 9-month in-stent late loss of 0.17 mm ± 0.25 mm was superior to the performance goal of 0.44 mm (P < .001) based on Taxus Express historical data and similar to in-stent late loss reported for the Promus (Xience V) everolimus-eluting stent in the SPIRIT trials.

PLATINUM QCA met a second prespecified efficacy endpoint of postprocedure incomplete stent apposition as measured by IVUS compared to Promus (Xience V) data from the SPIRIT III trial. The Promus Element postprocedure incomplete stent apposition of 5.7% was significantly below the performance goal of 34.4% (P < .001) based on Promus (Xience V) historical data. Net volume obstruction at 9 months was also low at 7.2%, as measured by IVUS.

“The 9-month angiographic and IVUS data from the PLATINUM QCA study are impressive and show the acute performance advantages of the platinum chromium Promus Element stent,” commented Professor Meredith. “With the same drug and polymer loading and comparable release kinetics as the Promus stent, the Promus Element stent achieved similar late loss and significantly better stent apposition. These results give me great confidence in the transferability of the everolimus drug and its proven clinical outcomes, as well as the potential benefits of the new platinum chromium alloy.”

In the United States, the Promus Element and Taxus Element systems are investigational devices and are limited by applicable law for investigational use only and are not available for sale. Boston Scientific expects to receive Food and Drug Administration approval for the Taxus Element stent system in mid-2011 and for the Promus Element stent system in mid-2012. In Japan, the company expects approval for the Taxus Element stent system in late 2011 or early 2012 and for the Promus Element stent system in mid-2012.

The company advised that 1-year data from the PLATINUM Workhorse trial will be presented at the Scientific Session of the American College of Cardiology/i2 Summit in March 2011. The randomized controlled PLATINUM Workhorse clinical trial completed enrollment in September 2009, with 1,531 patients at more than 130 sites worldwide, and compares the Promus Element everolimus-eluting coronary stent system to the Promus (Xience V) everolimus-eluting coronary stent system.