First Bioabsorbable Stent Approved in Europe

January 10, 2011

January 10, 2011 (Abbott Park, Illinois) — The world's first market approved, bioabsorbable stent will soon be available in Europe, with Abbottannouncing today that it hasreceived CE Mark approval for the Absorb everolimus-eluting bioresorbable vascular scaffold (BVS) stent. The stent utilizes a poly-L-lactide polymerand is approved for the treatment of coronary artery disease.

Approval is based on the ABSORB clinical trials, previously reported by heartwire , showing the feasibility of the BVS device and the durability of its antirestenotic properties. Imaging studies published in 2009, also reported by heartwire , showed that at least one-third of the stent had been absorbed by the vessel wall by two years. Patients in the ABSORB trial have now been followed out to three years, according to the company.

Larger studies are still in the works, however, including a European trial that will enroll approximately 500 patients at 40 centers. In this study, patients will be randomized to the Absorb BVS stent and to Abbott's Xience PRIME stent, which has a permanent cobalt-chromium platform, while a global trial, which will include centers in the US, is planned for late 2011. 

The Absorb stent will be available in a select number of sizes at various European centers in 2011, but a full commercial launch is expected in 2012, according to Abbott. 

The potential for a stent that does its job and then disappears, with no long-term need for dual antiplatelet therapy, has been a holy grail in interventional cardiology. Even those excited about the technology, however, have worried about its deliverability and whether the stent can achieve the same low rates of restenosis seen with some of the newest permanent-scaffold drug-eluting stents.

In an email to heartwire , Dr Gregg Stone (Columbia University, New York) said he is enthusiastic about the potential of bioabsorbable stents and cited a number of reasons that the disappearing scaffold might be advantageous: the ability to restore normal vasomotion, the potential for plaque regression, and the ability to decrease late stent thrombosis, late angiographic in-stent hyperplasia, and neoatherosclerosis. In addition, the bioabsorbable stents do not "permanently jail side branches" or curtail the future use of noninvasive imaging for follow-up.

"It will take many large-scale randomized trials to investigate these benefits," Stone noted, however.

Contrasting the European Union (EU) approval with the US Food and Drug Administration, Stone said the EU tends to approve devices after a minimal amount of safety has been shown. The two cohorts with the Absorb BVS stent--cohort A included 30 patients followed for more than two years and cohort B included 101 patients followed for six months--showed no stent thromboses and favorable late-loss data, along with an excellent safety profile, in patients with simple lesions.

"In contrast, the FDA requires a much higher bar of at least statistical noninferiority to be established compared with predicate devices prior to approval, which we anticipate will require a large-scale randomized trial and several more years to accomplish," wrote Stone. "Personally, I am comfortable with the FDA approach with regard to [drug-eluting stents] DES given their frequency of use.  While we only have four approved DES, at least we can be confident these four are safe and effective. In the EU, there are 25 or more DES that are commercialized. The system there places more trust in the physician and market forces to determine choice of device."