A proprietary ultra-thin abluminal (outer) bioresorbable PGLA polymer coating has been used in US medical device manufacturer Boston Scientific's Synergy everolimus-eluting platinum chromium coronary stent system, which received CE Mark approval on October 31, 2012.
The Synergy stent is the latest innovation in drug-eluting stent technology from Boston Scientific. It is unique in that its proprietary PLGA polymer and everolimus drug coating dissipate by three months. This innovation has the potential to improve post-implant vessel healing and will eliminate long-term polymer exposure, a possible cause of late adverse events.
"With the Synergy stent, drug release and polymer absorption occur in parallel and are complete at about three months after stent implantation," said Ian Meredith, professor and director of Monish Heart, at Monish Medical Centre in Melbourne, Australia, and the principal investigator of the Evolve clinical study, a six-month study which demonstrated that the Synergy stent is not inferior to Boston Scientific's previously released Promus Element stent. "This exciting advance may improve long term safety and efficacy compared to current durable polymer drug eluting stents and perhaps even reduce the need for prolonged dual antiplatelet therapy."
The timely absorption of the Synergy stent coating is the result of seven years of research and development to create what Boston Scientific believes to be the ideal blend of drug and polymer with advanced coating technologies.
"In addition to its innovative coating, the foundation of the Synergy stent is our proprietary platinum chromium alloy and an enhanced stent design which allow for thinner struts, increased visibility and an extremely low crossing profile for easier deliverability," said Kevin Ballinger, president of the Interventional Cardiology division at Boston Scientific. "We believe that the result is a premium workhorse drug-eluting stent that eliminates long-term polymer exposure, promotes optimal healing and provides confident deliverability."
The Synergy stent is supported by a rigorous clinical programme and builds on the Evolve six-month study results which demonstrated non-inferiority to the Boston Scientific Promus Element stent for the primary angiographic endpoint of in-stent late loss, a proxy for efficacy. At 12 months, the Synergy stent demonstrated a target lesion revascularisation (TLR) rate of 1.1% and a stent thrombosis (ST) rate of 0.0%. A pivotal trial, Evolve II, has been designed to support US FDA and Japanese Ministry of Health, Labor and Welfare approval of the Synergy stent system and is expected to begin enrollment later this year. Evolve II is a global, multi-centre, randomised, controlled (RCT), pivotal trial that will enroll 1,684 patients in 160 sites across the globe. Boston Scientific anticipates additional studies to assess outcomes, including the potential for reduced dual antiplatelet therapy.
The Synergy stent will be available in a full range of sizes to select centres in Europe and other geographies by early 2013. This limited market release is expected to provide additional data to support the clinical and economic benefits of this novel bioabsorbable technology. A broad commercial launch of the Synergy Stent is planned for early 2014.
The Synergy stent system is an investigational device, not available for sale in United States and Japan.