Updated on Oct. 29 with comments from Endologix.
Endologix (NSDQ:ELGX) shares plummeted today after the FDA issued a warning for patients using the company’s AFX endovascular stent grafts for the treatment of abdominal aortic aneurysms.
The AFX with Duraply and AFX2 were all mentioned by the FDA as stent grafts with a risk of endoleaks, along with the AFX with Strata, which the FDA warned on in June 2018 after it was recalled in December 2016.
The FDA said it has approved various endovascular stent grafts for the treatment of AAA, but if a patient has any type of Endologix AFX graft, they should contact their health care provider. Data showed that the AFX grafts can lead to a higher-than-expected risk of blood leaking into the AAA in a Type III endoleak, which can lead to serious injury, including death, according to a news release.
Endologix’s AFX with Duraply has been implanted in patients since July 2014, according to the FDA. The change in graft material from Strata to Duraply was intended to help prevent Type III endoleaks.
The AFX2 is also made with Duraply material and has been implanted since February 2016 with updates to the Duraply manufacturing to increase average thickness, again in an effort to prevent Type III endoleaks.
A recent conference abstract referenced by the FDA and published in the Journal of the American College of Surgeons found that there was a 2.5% cumulative probability of additional procedures needed to treat Type III endoleaks at two years of follow-up for patients treated with AFX grafts. The FDA acknowledged limitations in the data, given that there were 32 patients observed with AFX2, 197 with AFX with Duraply and 374 patients with AFX with Strata.
The FDA also noted Endologix’s ongoing Leopard trial, which is observing AAA patients randomly given either an AFX device with Duraply or an FDA-approved endovascular graft from other manufacturers. Recent data from that trial showed the cumulative probability of Type III endoleaks from AFX devices is 1%, compared to 0% from the other grafts.
Shares of ELGX were down -19.5% at $2.89 per share in mid-afternoon trading yesterday.
In an Oct. 29 statement, Endologix disputed the clinical meaningfulness of the data behind the study cited by the FDA.
“The information from Rothenberg et. al, contains retrospectively collected data on 603 patients treated with the AFX Systems between 2011 and 2017 who had a 2.5% cumulative Type III endoleak rate at 2 years,” Endologix chief medical officer Dr. Matt Thompson said in prepared remarks. “The objectives of the study were described as to provide crude mid-term postoperative outcomes with the Endologix AFX/AFX2 devices. The FDA noted limitations with the data from Rothenberg et. al.in its October 28th update, including the small number of patients implanted with AFX2 (32 patients), the results not being stratified by Type IIIa and Type IIIb endoleaks, and the lack of a comparison of these results to the results from other endovascular graft systems. In our view, the small number of patients with AFX2 at 2 years (13 patients) prevents any clinically meaningful interpretation of these findings. The FDA update provides certain recommendations for patients implanted with AFX, including the need to undergo lifelong yearly surveillance, a practice that is already detailed in the AFX System’s instructions for use as well as in Endologix’s 2016 AFX safety notice and is standard practice with all aortic endografts.”
“Our current commercially available versions of the AFX System: the AFX Duraply and AFX2 products, are manufactured using a different ePTFE processing methodology than AFX Strata and include additional product improvements,” added CEO John Onopchenko. “Endologix has a robust approach to monitoring the performance of our products through the use of multiple data sets that are benchmarked, compared against other commercially available endografts, and analyzed for concordance. These data include the Leopard trial (the only randomized controlled trial of EVAR providing Level 1 evidence), real world data from a vascular registry, our benchmarked MDR complaint data, and meta-analyses of current literature. All of the data sets we use are concordant and demonstrate, through the prospective analysis of 62,461 patients with the AFX system, that our AFX Duraply and AFX2 Systems currently achieve patient outcomes equivalent to other contemporary commercialized endografts, when assessed on an encompassing spectrum of clinical complications.”
