There are two ways to make a bioresorbable, drug-eluting scaffold, according to Amaranth Medical CEO Kamal Ramzipoor.
“The Amaranth way, or the conventional way, which our competition is using,” he told Drug Delivery Business News. “What we’ve seen throughout the years is the conventional method has some very significant limitations. And that’s what has manifested itself into, unfortunately, what’s going on.”
Bioresorbable scaffolds have been plagued by safety concerns, highlighted recently by Abbott‘s (NYSE:ABT) Absorb device, which it pulled from the market in September due to low sales. In October, a European task force recommended that physicians favor current-generation drug-eluting stents over bioresorbable scaffolds, citing concerns about the increased risk of myocardial infarction and scaffold thrombosis linked with bioresorbable devices.
Amaranth’s chief executive said he knows that his company’s devices need to live up to the efficacy expectations set by drug-eluting stents.
“We have leveraged the capability and the potential of the proprietary polymer technology that we use and that’s what is enabling us to really produce a scaffold that basically mimics what you see with the best-in-class drug-eluting stents,” Ramzipoor said. “It’s as close as it gets to a metallic drug-eluting stent.”
The only way the industry is going to move forward is with strong clinical data, he said, and at this year’s Transcatheter Cardiovascular Therapeutics meeting, Amaranth touted data for three of its bioresorbable scaffolds.
The company has developed and is testing three different sirolimus-eluting scaffolds, each with a different strut-thickness. Amaranth presented two-year safety and efficacy data for its 150-micron device, Fortitude, as well as nine-month follow-up data for its 115-micron Aptitude scaffold.
After two years with Amaranth’s Fortitude device, 30 patients showed a mean in-scaffold late lumen loss of 0.27 (+/-0.37) mm. The company also reported that at nine months, its Fortitude product demonstrated a 3.3% rate of target vessel myocardial infarction and a 1.6% rate of ischemia driven TLR.
Its 115-micron device, Aptitude, had a target vessel myocardial infarction rate of 3.4% after nine months.
Amaranth also touted data from its first sub-100 micron device, Magnitude. After thirty days, that product had a target vessel MI rate of 4.3%.
The company said that early imaging data suggests that its 98-micron device performs like a drug-eluting stent, in terms of angiographic restenosis and strut healing response.
Amaranth also said it plans to bring an 80-micron scaffold into clinical trials next year.
“The clinical success of the BRS field depends on the development of <100-micron scaffolds capable to provide long-term structural stability,” Dr. Juan Granada of the Cardiovascular Research Foundation wrote in his presentation of Amaranth’s latest results.
Although Ramzipoor acknowledges that problems with Abbott’s devices could be distracting, the CEO sees an opportunity to learn from the short-comings of his company’s competitors.
“It’s an unfortunate thing, obviously, with safety-concerns. Thrombosis is obviously very, very serious. One thing we’ve noticed is that there is a notion of a class effect – industry is basically put in a category and there is a notion that anybody who is in this space will potentially see the same kind of safety concerns. And that is definitely having an indirect effect on us,” he said. “We think, at the end of the day, if you really produce a scaffold that has all the attributes of a metallic stent, until it reaches the point of dismantling and it goes away – if you achieve that, by definition you have solved the thrombosis issue.
“We were able to navigate our way through and create something that is very, very unique.”