Hours before Abbott (NYSE:ABT) presented three-year data from a pivotal trial of its Absorb bioresorbable scaffold, the FDA updated a letter to healthcare providers, writing that the device continues to show an increased rate of major adverse cardiac events and thrombosis compared to patients treated with a drug-eluting stent.
“The FDA’s recommendations for health care providers outlined in our previous letter remain unchanged,” the agency wrote. “Although health care providers with available inventory may continue to implant the BVS, they should carefully consider its safety and effectiveness and only use it if they believe it is in the best interest of their patients.”
Earlier this year, Abbott halted global sales of its Absorb device, citing low sales. The company issued a statement yesterday, commenting on a 30-day study and four-year data presented at the annual Transcatheter Cardiovascular Therapeutics meeting.
“Data at TCT support avoiding small vessels, using current implantation technique and suggest promising results following stent resorption,” the company said. “The first available four-year data for Absorb (Absorb II) showed no stent thrombosis after the stent dissolved. And the first study to not include small vessels (Absorb IV) showed a 30-day stent thrombosis rate in line with current-generation drug-eluting stents. We believe that bioresorbable technologies offer patients the possibility of life without permanent metallic implants, and we will continue to monitor long-term outcomes after stent-resorption in current Absorb trials.”
At the TCT meeting yesterday, Dr. Stephen Ellis reviewed the three-year follow-up data from 686 patients assigned to a drug-eluting stent and 1,322 patients given Abbott’s BRS.
After three years, target lesion failure occurred in 13.4% of patients treated with a BRS and 10.4% of patients given a DES. The investigators also reported that the incidence of target-vessel myocardial infarction was 8.6% in the BRS group , compared to 5.9% of the DES group.
Device thrombosis also happened more often in patients given Absorb compared to people treated with the company’s Xience DES.
“The Absorb III study showed a 2.3% rate of thrombosis within the BVS scaffold versus 0.7% within the Xinece stent at 3 years (p = 0.01). Most cases of BVS scaffold thrombosis occurred within the first year after BVS implantation, but beyond 1 year, the rate of new thrombosis events remained higher in BVS patients versus Xience patients,” the FDA wrote.
In the company’s Absorb IV trial, which compared Absorb to a cobalt-chromium everolimus-eluting stent, Abbott avoided enrolling patients with small vessels. Although the study found Absorb to be non-inferior to the drug-eluting stent for target lesion failure after 30 days, investigators reported seeing similar trends to other Absorb trials.
“The rates of non-peri-procedural MI and ID-TLR at 30 days were greater with BVS than with CoCr-EES, and a trend toward greater stent thrombosis with BVS was present. Compared to Absorb III, reducing the number of very small vessels treated in Absorb IV substantially reduced the device thrombosis rate in both groups. These results are largely consistent with those from earlier Absorb trials, and highlight the need for continued advancements in device technology and standardized technique to further improve the early safety profile of BVS,” Dr. Gregg Stone, chairman of the Absorb global clinical trial program, said in prepared remarks.
