An FDA advisory committee announced last week that it is backing a new drug-eluting stent for conditional approval.
Pacemaker manufacturer Medtronic developed the stent, dubbed Endeavor, which touts a very low rate of late thrombosis in clinical trials. "In all the patients studied, we have seen no sign of thrombosis after one year," said Dan Beach, director of communications at Medtronics. "The stents appear to offer the efficacy advantages of the bare-metal stents, but with no thrombosis anywhere in the clinical program after six months."
The FDA panel recommended the stent technology unanimously but tacked on several conditions that Medtronics says it suggested in its presentation to the group. If approved, Medtronic will conduct a long postmarket clinical program so that it can monitor, capture, and confirm that the stents have a safety advantage in the long term, in a larger group of patients.
"The nomination paves the way for commercial launch after approval, either late in December, or in early 2008," Beach told Pharm Exec. "That's a best wish for us right now, but, obviously, it's in the hands of FDA."
Reducing Restenosis Stents offer structural support for arteries after angioplasty. The technology was very successful in reducing the restenosis rate, but it was leading to the formation of new cells in the vessels, which were growing around the stentwork, reclosing a vessel. The idea behind drug-eluting stents is to keep cells from proliferating by attacking them with medication attached to the stents.
In recent years, there have been concerns that drug-eluting stents were also leading to thrombosis after the recovery period. "All of a sudden, the market contracted sharply, because there were safety concerns over something that was previously thought to offer an efficacy advantage with no trade-off on safety," Beach said.
Johnson & Johnson (with Cordis) and Boston Scientific are currently the two largest suppliers of drug-eluting stents, and models from both companies were found to be associated with late thrombosis. "If the stent has been badly placed or if the stent hasn't conformed to the wall of the vessel, then you've got a significant risk of thrombosis," Beach said. "Very late stent thrombosis occurs when there is no longer a possibility that thrombosis can be caused through mechanical means, it has to be biological. Something was interfering with the healing process of the stent that was leading to clot forming after a year."
According to a statement by Martin B. Leon, principal investigator of the Endeavor clinical trials, "Rates of cardiac death, myocardial infarction, and stent thrombosis are exceptionally low with the Endeavor stent [after] three years of patient follow-up."