With a drug-eluting stent that promises more flexibility and safer outcomes after use, Abbott (Abbott Park, Illinois) plans to continue pushing past its competitors in the DES market. The company took a few steps and made further movements toward this goal yesterday, when it reported receiving the CE mark for its Xience Prime DES.

The Xience Prime stent is the next generation of the company's Xience V stent which gained FDA approval in July of last year. Xience V was the second of the 2.0 family of drug-eluting stents to win marketing approval in the U.S. (Medical Device Daily, July 8, 2008). Two years prior to its FDA clearance, the Xience V received the CE mark.

"Prime is poised to be the best selling [DES] in Europe and it will ultimately replace the Xience V," Jonathon Hamilton, senior director of public affairs for Abbott Vascular (Redwood City, California), told Medical Device Daily. "We have the same intent for the stent in the U.S. when it comes to market there, too."

Part of Prime's appeal will come from its maneuverability, which is poised to reach more difficult areas than its predecessor Xience V. Boasting a broader size model, the smallest Prime stent is nearly 10 mm larger than the largest Xience V stent.

"We designed Xience Prime with changes to the stent design and delivery system to offer physicians greater flexibility and improved deliverability, enabling them to more easily treat challenging lesions," Hamilton said.

The stent is available in an expanded size matrix, including Xience Prime SV for small vessels and Xience Prime LL for long lesions. Xience Prime uses cobalt chromium technology, which allows for very thin struts while maintaining strength to support the vessel as well as giving strong clarity and visibility under X-ray during the stent implantation procedure.

Plans call for the stent to be released in the U.S. within the first half of 2012 pending FDA approval. Currently, the company is testing the stents effectiveness in the SPIRIT PRIME clinical trial.

The study is a prospective, multi-center, nonrandomized trial and will include 500 patients at 75 hospital centers. Patients may receive a maximum of two stents in separate vessels. The stent will have two arms: the Core Size arm will follow 400 patients who will be treated with a stent from 2.25 mm to 4 mm in diameter and from 8 mm to 28 mm in length, and the Long Lesion arm will follow 100 patients who will receive a stent from 2.5 mm to 4 mm in diameter and either 33 mm or 38 mm in length. The primary endpoint is major adverse cardiac events, which is a composite measure of cardiac death, heart attack (myocardial infarction) and repeat procedure of the treated lesion (target lesion revascularization) at one year.

"I think one of the key advantages we have over the market really comes down to the clinical data we have for our stents," Hamilton said.

Hamilton pointed out that in a former SPIRIT clinical trial the company-sponsored, results indicated that Abbott's Xience V stent was much safer than rival Boston Scientific's (Natick, Massachusetts), Taxus, DES.

In the SPIRIT II trial, Xience V demonstrated a 69% reduction of in-stent late loss (a measure of vessel re-narrowing) at six months compared to the Taxus. In the SPIRIT III trial, Xience V demonstrated a 50% reduction of in-segment late loss (a measure of vessel re-narrowing) at eight months compared to Taxus. Long-term results further reinforce Xience performing better than Taxus clinical outcomes, with Xience V demonstrating an 88% reduction in cardiac death.

Hamilton said that the company was confident about the upcoming results for the SPIRIT PRIME trial also.

But while Abbott has opted to go the long route with its stent, Boston Sci recently reported taking a much different route to gain market share. The company said that it had gained FDA approval for its Taxus Liberté Atom paclitaxel-eluting coronary stent system, a DES for use in vessels as small as 2.25 mm in diameter – something it says no other company has on the market (MDD, May, 28, 2009).

In a May interview, Boston Scientific told MDD, that it would be able to dominate the market for the 2.25 mm size in stents since no other company was close to obtaining clearance. A spokesman from Boston Scientific did say that the only company close to gaining approval was Abbott, but by the time that company could gain FDA approval for a stent of that size (which is estimated to be around 2012); the Taxus developer would have already established the Libert Atom Stent as a leading product.

Both stents are expected to dominate a market previously filled by first-generation DES devices, such as the Cypher from Johnson & Johnson's (J&J; New Brunswick, New Jersey) Cordis (Miami Lakes, Florida) unit.

Published: June 24, 2009