By Stephanie Riesenman
Guidant Corporation (a corporate underwriter for Heart1.com) announced it will be delaying introduction of its CHAMPION Drug Eluting Stent Program by 6 to 8 months in order to implement changes to its material processing and stent design after an internal review of the product revealed fractures in a small number of its stainless steel Champion stents.
"These are engineering types of challenges that Guidant has faced before and will solve," said Guido J. Neels, Guidant’s chief operating officer, in a conference with analysts on July 1st.
The problem was identified in a report in late May while the company was preparing to file an Investigational Device Exemption (IDE) with the Food and Drug Administration. What the company calls a "link fracture" was uncovered in a limited number of its CHAMPION stents. This device secretes a drug called everolimus; it’s also the first stent to utilize a bioabsorbable polymer — which is eventually fully absorbed by the body.
Dana Mead, Jr., president of the Vascular Intervention Division for Guidant, said the fracture would not be noticeable under fluoroscopy and did not show up during bench testing. The defect also was not apparent in any of the animal testing that was conducted.
The fracture was discovered on a specific radiograph, which would not typically be used to evaluate placement of a stent. Observers noticed the stent looked "awkward," according to Mr. Mead, and the fracture was discovered under magnification.
The fracture is described as "low stress, high fatigue," and is caused by repetitive stress. To explain what that means, Mr. Mead gave the example of holding a pencil at both ends and slowly pushing down over time.
The company went back through all the data collected from its pre-clinical, clinical trials, and commercial experience with the stents. Mr. Meade said, "The evaluation confirmed that the overall safety and efficacy profile of this platform is consistent with commercially available metallic and drug eluting stents."
Guidant scientists were able to recreate the fracture in the lab in order to observe what was wrong with the design and to come up with a solution that addresses material processing and stent design. The company said the changes improve the stainless steel stent platform and address performance and quality concerns.
After a recent meeting with the FDA and European regulatory authorities to discuss Guidant’s findings and its plan to resolve the issues, the company was told it would not have to submit any additional clinical data. But Guidant must first show that the revised CHAMPION stent passes standard stent performance testing and validations.
The FDA and European authorities said the FUTURE I and FUTURE II clinical trial data would be enough to support European approval along with commencement of FUTURE IV. Both trials evaluated safety and performance of the everolimus eluting stent with a bioabsorbable polymer drug carrier and stainless steel stent platform. The CHAMPION stents were shown to prevent restenosis—or a narrowing of the vessel into the stent caused by tissue regrowth — at both 6 months and 1 year follow up in patients with coronary artery disease.
Guidant is anticipating it will file an IDE application with the FDA in the first quarter of 2005 and to launch CHAMPION Everolimus Eluting Coronary Stent System in Europe in mid-2005.
"I’m confident in the CHAMPION Program," said Mr. Neels, "and it remains our lead drug-eluting stent program."
Last updated: 12-Jul-04
