Independence Day wasn't the only thing Abbott (Abbott Park, Illinois) celebrated over the weekend. FDA approval of the company's Xience stent was reason enough to shoot off fireworks.

Abbott received approval of the Xience V everolimus-eluting coronary stent for the treatment of coronary artery disease late on Wednesday, making it the second of the 2.0 family of drug-eluting stents to win marketing approval in the U.S.

Medtronic's (Minneapolis) Endeavor DES, which won approval in February, was the first second-generation DES to hit the U.S. market (Medical Device Daily, Feb. 4, 2008). Both products are expected to elbow aside to a considerable extent the first-generation DES devices, the Cypher from Johnson & Johnson's (J&J; New Brunswick, New Jersey) Cordis (Miami Lakes, Florida) unit, and the Taxus from Boston Scientific (Natick, Massachusetts).

Abbott says its Xience stent, which went on commercial sale, is the only DES to have demonstrated superiority over Boston Scientific's Taxus paclitaxel-eluting coronary stent system.

Kelly Morrison, an Abbott spokeswoman, told Medical Device Daily that the first implant was performed last Thursday morning at New York Presbyterian Hospital/Columbia University Medical Center (New York).

"The strength of the data supporting Xience V is really unprecedented," Morrison said. "It's the first to show superiority over the market leading drug-eluting stent in clinical trials, it demonstrated a 45% reduction in major heart related events compared to Taxus at two years."

Because the device is based on Abbott's market-leading Multi-Link Vision bare-metal stent platform, Morrison said the company expects a healthy physician adoption of Xience.

"I think physicians have been waiting for a next-generation technology that really delivers on the promise of drug-eluting stents," Morrison said. "We've been hearing from physicians that they're very excited [about Xience] based on the clinical data."

Abbott is expecting a 25% to 30% market share in the U.S. within the first year of launch, Morrison said.

"Xience V represents an important treatment advance for the estimated 13 million people in the U.S. suffering from coronary artery disease, and we believe Xience V will quickly become the new standard for drug-eluting stents given its outstanding clinical results," said John Capek, PhD, executive VP of medical devices at Abbott.

Xience won a panel recommendation for approval in early December (MDD, Dec. 3, 2008). The stent is used to treat heart disease by propping open a narrowed or blocked artery and releasing the drug, everolimus, in a controlled manner to prevent the artery from becoming blocked again following a stent procedure, Abbott said. The stent will be available on both over-the-wire and rapid exchange (RX) delivery systems.

Xience was launched in Europe and other international markets in October 2006. It is an investigational device in Japan and is currently under review for approval by Japan's Ministry of Health, Labor and Welfare and the Pharmaceuticals and Medical Devices Agency.

Everolimus, developed by Novartis Pharma (Basel, Switzerland), is a proliferation signal inhibitor, or mTOR inhibitor, licensed to Abbott for use on its drug-eluting stents. Everolimus has been shown to inhibit in-stent neointimal growth in the coronary vessels following stent implantation, due to its antiproliferative properties, the company noted.

Approval of Xience also was good news for Boston Scientific, which will share profits from the device. Guidant had been developing the stent and when Boston Scientific acquired that company, it had to divest the stent to Abbott, but it retained the right to sell the same device as the Promus under a private-label arrangement.

"The Promus stent has shown outstanding deliverability, low late loss and the potential to reduce the need for re-interventions," said Ted Feldman, MD, director of the cardiac catheterization lab at Evanston Northwestern Healthcare (Evanston, Illinois). "These benefits will make the Promus stent an attractive new treatment option for U.S. physicians and their patients."

Jim Tobin, president/CEO of Boston Scientific, said the approval fulfills the company's promise of an "unprecedented two-drug strategy two distinct drugs on two highly deliverable stent platforms."

Wachovia Capital Markets device analyst Larry Biegelsen, in a research note, said he expects Xience to capture share more quickly in the U.S. than in Europe. The company now indicates that Xience, including Promus, has surpassed Taxus' market share in Europe after about 19 months post-launch, Biegelsen said. "We expect Xience alone to reach this level in the U.S. after only 12 months," he said, due to widespread reimbursement, more compelling clinical data at the time of launch, the absence of Taxus Liberte and Cypher Elite, the lack of RX delivery for Endeavor in the U.S. and the absence of small European competitors.

The key barriers for Xience are likely to be the competitive pricing and contract arrangements between cath labs and Boston Scientific and J&J, Biegelsen noted.

"Xience V was designed to improve safety and efficacy compared to earlier generation stents. The long-term clinical data from two studies performed in both the U.S. and Europe have now confirmed that Xience V is a true next-generation drug-eluting stent with clinically important benefits for patients," said Gregg Stone, MD, of Columbia University Medical Center (New York), chairman of the Cardiovascular Research Foundation (also New York) and the principal investigator of the SPIRIT III U.S. pivotal clinical trial for Xience.

The robust clinical program for Xience includes long-term data from a total of 1,362 patients enrolled in the SPIRIT FIRST, SPIRIT II and SPIRIT III trials, as well as continued access and post-approval programs that will enroll more than 14,000 Xience patients, Abbott noted.

The FDA approved Xience based, in large part, on superior results from the 1,002 patient SPIRIT III U.S. pivotal clinical trial, in which the device demonstrated statistical superiority to Taxus on the study's primary endpoint of in-segment late loss (vessel renarrowing) at eight months, with a statistically significant 50% reduction.

The company said Xience also demonstrated statistical non-inferiority to Taxus in the co-primary endpoint of target vessel failure (TVF) at nine months, with an observed 20% reduction. TVF is a composite clinical measure of safety and efficacy outcomes defined as cardiac death, heart attack or target vessel revascularization.