Abbott announced on 25 May 2005 positive six-month results from the first 45 patients enrolled in the second stage of the ABSORB trial, which was presented during the Late-Breaking Clinical Trials session at the EuroPCR 2010 conference. At six months, Abbott’s bioresorbable vascular scaffold (BVS) demonstrated strong results, with a low (4.4%) rate of major adverse cardiac events (MACE) and no blood clots (thromboses). BVS also demonstrated an in-stent late loss rate of 0.19mm.
“With each new data milestone, Abbott’s revolutionary BVS technology is one step closer to becoming a reality. The device achieved a six-month late loss rate of 0.19mm. This finding suggests that the BVS may have the potential to treat a blocked vessel as effectively as a metallic drug eluting stent, with the added potential benefit of not leaving a permanent implant behind after the vessel is healed,” said Patrick W Serruys, professor of interventional cardiology at the Thoraxcentre, Erasmus University Hospital, Rotterdam, The Netherlands, and principal investigator for the ABSORB trial. “These extraordinary findings signal that Abbott’s disappearing scaffold may become the new standard of care for treating coronary artery disease.”
BVS, which is under clinical investigation in Europe, Australia and New Zealand, and is not currently available for sale anywhere in the world, is made of polylactide, a proven biocompatible material that is commonly used in medical implants such as dissolving sutures. The bioresorbable technology is designed to restore blood flow by opening a clogged vessel and providing support until it is healed. Once the vessel can remain open without the extra support, the bioresorbable scaffold is designed to be slowly metabolised and eventually resorbed by the body. Since a permanent implant is not left behind, a vessel treated with a BVS ultimately may have the ability to move, flex and pulsate similar to an untreated vessel. The potential to restore these naturally occurring vessel functions, or vascular restoration, is one of the features that will make Abbott’s BVS unique in the treatment of coronary artery disease.
The ABSORB trial is a prospective, non-randomised (open label), two-phase study that enrolled 131 patients from Australia, Belgium, Denmark, France, The Netherlands, New Zealand, Poland and Switzerland. Key endpoints of the study include assessments of safety – MACE and treated site thrombosis rates – at 30 days; six, nine, 12 and 24 months; with additional annual clinical follow-up for up to five years, as well as an assessment of the acute performance of the bioresorbable vascular scaffold, including successful deployment of the system. Other key endpoints of the study include imaging assessments by angiography, intravascular ultrasound (IVUS), optical coherence tomography (OCT), and other state-of-the-art invasive and non-invasive imaging modalities at six, 12, 18 and 24 months. The next 56 patients in the second phase of the ABSORB trial will undergo imaging follow-up one year after their procedures, and all 101 patients in the second phase of the trial will receive follow-up imaging at two years.
Abbott’s bioresorbable technology delivers everolimus, an antiproliferative drug. Everolimus is developed by Novartis Pharma AG and is licensed to Abbott by Novartis for use on its drug-eluting vascular devices. Everolimus has been shown to inhibit treated site neointimal growth in the coronary vessels following vascular device implantation, due to its antiproliferative properties.