"Now you see it, now you don't – for the first time, we have data in patients showing that Abbott's bioabsorbable drug eluting stent does its job treating diseased coronary arteries and that it is absorbed by two years," said John Ormiston, M.D., principal investigator in the ABSORB trial and medical director at Mercy Angiography in Auckland, New Zealand."Clinical safety and effectiveness were sustained at two years, and the previously stented portion of arteries demonstrated the ability to expand and contract in a manner similar to a vessel that has never been stented. These are very exciting results that represent a potential major breakthrough in the future treatment of patients with coronary artery disease."
Trends were observed in data from tests of artery movement and function, demonstrating a potential restoration of unstented artery movement to coronary blood vessels after the stent was absorbed – something that is not possible with permanent metal-based stent implants.
Abbott also will present groundbreaking intravascular ultrasound (IVUS) and optical computed tomography (OCT) imaging data on its bioabsorbable drug eluting coronary stent platform this week at TCT in the "Best of Coronary Interventions Abstracts" session at 9:20 a.m. Eastern time on Wednesday, October 15, 2008. IVUS data will reveal a decrease in plaque area in treated arteries corresponding to a similar increase in blood flow area between six months and two years: 12.7 percent decrease in plaque area (p=<0.001, n=17); 10.8 percent increase in luminal area (p=0.03, n=17). OCT imaging data will show absorption of the stent into artery walls and that the blood vessel lining of arteries treated with Abbott's bioabsorbable stent looks more uniform after two years than it did immediately post-treatment.
"The imaging technology data from the ABSORB trial indicate that Abbott's bioabsorbable stent has the potential to restore vascular integrity and endothelial function to treated vessels after two years," said Professor Patrick W. Serruys, M.D., Ph.D., professor of interventional cardiology at the Thoraxcentre, Erasmus University Hospital, Rotterdam, and co-principal investigator in the ABSORB trial. "With these ABSORB data, we have come full circle in interventional time, linking the past, when balloon angioplasty was used without stents, to the future, when disappearing stents may become the new standard of care for patients with coronary artery disease."
Abbott is the only company with long-term clinical data evaluating the safety and performance of a fully bioabsorbable drug eluting coronary stent out to two years. Abbott’s bioabsorbable everolimus eluting coronary stent is made of polylactic acid, a proven biocompatible material that is commonly used in medical implants such as dissolvable sutures. As with a metallic stent, Abbott’s bioabsorbable stent is designed to restore blood flow by propping a clogged vessel open, and to provide support until the blood vessel heals. Unlike a metallic stent, however, a bioabsorbable stent is designed to be slowly metabolized by the body and completely absorbed over time.
"The early success of our bioabsorbable stent marks the dawn of the beginning of a new era in the history of interventional medical device treatment," said John M. Capek, Ph.D., executive vice president, Medical Devices, Abbott. "Today’s data show that bioabsorbable stents have become more than just a wish for patients – they are now on their way to becoming a clinical reality."
Abbott will begin enrolling the next cohort of 80 patients into its international ABSORB clinical trial in the first half of 2009.
ABSORB Clinical Trial Results
Two-year data from the first 30 patients enrolled in the ABSORB clinical trial demonstrated a low (3.6 percent, n=28) MACE rate, which was consistent with results at one year (3.4 percent, n=29) and before six-months (3.3 percent, n=30). One patient had a minor heart attack due to lack of blood supply at six-months, another was electively lost to follow up at one year, and one patient died from a non-cardiac cause at two years. A zero percent stent thrombosis rate persisted for all patients across all time points in the ABSORB trial. Potential restoration of unstented artery movement to coronary blood vessels after the bioabsorbable stent was absorbed was revealed at two years with the drugs acetylcholine and nitroglycerin used in nine patients, showing vasodilation in the previously stented area, and methergine used in seven patients, showing vasoconstriction in the previously stented area.
About the ABSORB Clinical Trial
The ABSORB trial is a prospective, non-randomized (open label) study designed to enroll up to 110 patients in Belgium, Denmark, France, New Zealand, Poland and the Netherlands. Key endpoints of the study include assessments of safety – MACE (defined as any event that resulted in re-treatment of the treated artery, heart attack or cardiac death) and stent thrombosis (blood clot formation) rates – at 30, 180 and 270 days, with additional annual follow-up for up to five years, as well as an assessment of the acute performance of the bioabsorbable drug eluting stent. Other key endpoints of the study include successful deployment of the bioabsorbable drug eluting stent, follow-up measurements assessed by angiography, intravascular ultrasound (IVUS), and state-of-the-art imaging modalities at 180 days and two years.
Everolimus, developed by Novartis Pharma AG, is a proliferation signal inhibitor, or mTOR inhibitor, licensed to Abbott by Novartis 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 anti-proliferative properties.
For images of Abbott’s bioabsorbable stent and other information, please visit the company’s online TCT newsroom at www.abbottvascular.com/presskit.
About Abbott Vascular
Abbott Vascular, a division of Abbott, is one of the world's leading vascular care businesses. Abbott Vascular is uniquely focused on advancing the treatment of vascular disease and improving patient care by combining the latest medical device innovations with world-class pharmaceuticals, investing in research and development, and advancing medicine through training and education. Headquartered in Northern California, Abbott Vascular offers a comprehensive portfolio of vessel closure, endovascular and coronary products.
Abbott is a global, broad-based health care company devoted to the discovery, development, manufacture and marketing of pharmaceuticals and medical products, including nutritionals, devices and diagnostics. The company employs more than 68,000 people and markets its products in more than 130 countries.