Now You See It: FDA Approves Absorb Bioresorbable Scaffold
Physicians in the United States will now have access to the first commercially available “dissolving” stent for the treatment of patients with coronary artery disease following today’s US Food and Drug Administration (FDA) approval of the Absorb GT1 bioresorbable vascular scaffold (BVS; Abbott Vascular).
According to information released by the company, the FDA has approved the Absorb device for the treatment of coronary artery disease, making it “the first of its kind” in the United States for this indication. The Absorb GT1 system consists of an absorbable polymeric scaffold and polymer, both of which are completely broken down and dissolved within 36 months of implantation.
“The FDA’s approval of the Absorb GT1 BVS offers a new treatment option for individuals who are candidates for angioplasty, but would prefer an absorbable device rather than a permanent metallic coronary stent,” Bram Zuckerman, MD, director of the division of cardiovascular devices at the FDA’s Center for Devices and Radiological Health said in the FDA’s announcement of the news.
Gregg Stone, MD (Columbia University Medical Center, New York, NY), chair of the ABSORB clinical trial program, called the new device “a major advance in the treatment of coronary artery disease,” according to the company’s news release. “This novel technology appeals to both physicians and patients alike because after treating the underlying blockage it is completely absorbed, leaving nothing behind,” he said.
In March, the FDA’s Circulatory System Devices Panel voted overwhelmingly in favor of approving the Absorb everolimus-eluting bioresorbable vascular scaffold, stating unequivocally that the benefits of the stent outweighed the potential risks. At that time, the sponsor was specifically seeking an indication for the treatment of de novo native coronary lesions measuring 24 mm or less in length with a reference vessel diameter ranging from 2.5 mm to 3.75 mm.
Indications for use, posted online shortly after the initial announcement, are in keeping with those sought by the sponsor in March. “The GT1 BVS is a temporary scaffold that will fully resorb over time and is to be used in patients who have a narrowing in their coronary artery lesions that is less than or equal to 24 mm long with a reference vessel diameter of ≥ 2.5 mm and ≤ 3.75 mm,” the FDA website reports.
The recommendation and subsequent approval is based on data from the ABSORB III study, a head-to-head comparison of Absorb against a conventional everolimus-eluting cobalt-chromium stent (Xience, Abbott Vascular). At 1 year, the two devices yielded similar rates of target lesion failure, the study’s primary composite endpoint of cardiac death, target-vessel MI, or ischemia-driven target lesion revascularization. The rate of device thrombosis was numerically higher in patients treated with Xience, although the difference was not statistically significant.
Several meta-analyses have suggested the Absorb stent is associated with a higher risk of scaffold thrombosis compared with the conventional drug-eluting stents. As reported by TCTMD, one meta-analysis of six clinical trials, including the ABSORB studies, found an approximately twofold higher risk of definite or probable scaffold thrombosis after a median of 12 months. While others have shown similar risks, in one patient-level meta-analysis investigators found comparable safety and efficacy between Absorb and drug-eluting stents.
In a recent survey of operators experienced with Absorb—the stent has been commercially available in Europe since 2011—the majority felt the risk of scaffold thrombosis was not an issue, at least not any more so than the risk of stent thrombosis with contemporary drug-eluting stents.
- FDA Panel Overwhelmingly Supports Absorb Bioresorbable Stent
- Increased Early Risk of Stent Thrombosis With the Absorb Bioresorbable Scaffold
- ABSORB III: Novel Bioresorbable Scaffold as Good as Standard-of-Care DES
Ellis SG, Kereiakes DJ, Metzger C, et al. Everolimus-eluting bioresorbable scaffolds for coronary artery disease. N Engl J Med. 2015;373:1905-1915.