Despite the safety concerns plaguing Abbott‘s (NYSE:ABT) Absorb device, companies developing bioresorbable scaffolds are not discouraged. This week at the annual Transcatheter Cardiovascular Therapeutics Conference in Denver, a number of companies touted the safety data coming from clinical trials of their products.
Reva Medical’s Fantom coronary scaffold
The San Diego, Calif.-based company reported an interim data set of 125 patients that the company followed for two years and revealed plans for its next-gen device, called Fantom Encore.
Reva said that the interim data set included a 5.6% rate of major adverse cardiac events and one very late scaffold thrombosis event. The company has previously reported a 4.2% major adverse cardiac event rate after 1 year, so Reva touted this two-year data set as demonstrating a sustained safety profile for its sirolimus-eluting Fantom device.
A 25-patient subgroup also underwent angiographic imaging to determine late lumen loss after two years, Reva said. The company found that its device produced a final in-scaffold late lumen loss of 0.25 mm.
“This preliminary data set from the Fantom II trial provides physicians with an early look at two-year clinical results for the Fantom scaffold,” trial investigator Dr. Ricardo Costa said in prepared remarks. “The low MACE rate and inscaffold late lumen loss measurement are encouraging as they demonstrate sustained safety and performance of Fantom out to 24 months in this group of patients.”
At TCT, Reva also unveiled plans for a scaffold with struts that are 95-microns thick.
“Reva’s announcement of 95 micron strut thickness for Fantom Encore in the 2.5 mm diameter is a promising development for bioresorbable scaffold technology,” Dr. James Hermiller of the Heart Center of Indiana added. “Bioresorbable scaffolds have the potential to offer patients short term benefits of metallic stents without the long-term complications. Thinner struts have been associated with improved deliverability and vessel healing.”
Biotronik’s Magmaris limus-eluting scaffold
Biotronik touted pooled 12-month data from its Biosolve-II and Biosolve-III trials, reporting a continuous absence of late definite or probable scaffold thrombosis with its Magmaris limus-eluting resorbable magnesium scaffold.
“We now have another set of evidence where even when pooling Biosolve-II and -III data, Magmaris shows zero percent definite and probable scaffold thrombosis for up to 12 months in clinical trials,” coordinating clinical investigator Dr. Michael Haude said in prepared remarks. “This adds to our understanding that approximately 95 percent of the magnesium scaffold is being resorbed within 12 months.”
Angiographic follow-up of 97 patients between the two trials showed in-segment late lumen loss of 0.25mm (+/-0.31mm) after one year. The company also reported a pooled target lesion failure rate of 3.3% at 12 months, comparable to second-gen drug-eluting stents.
“At a time when questions have been raised about poly-L-lactide (PLLA) scaffolds, we are pleased to once again report safe and efficacious results for Magmaris,” Alexander Uhl, VP of marketing for Biotronik’s vascular intervention business, added. “These data reiterate that magnesium-based resorbable technology is entirely different in both mode of action and clinical outcomes to PLLA-based bioresorbable scaffolds (BRS). We at Biotronik remain committed to vessel restoration therapy based on magnesium technology.”