Northeastern University researchers have formally petitioned the Food and Drug Administration (FDA) to revoke its approval of Symvess, a first-of-its-kind artificial blood vessel developed by Humacyte Global, citing significant safety concerns and questionable clinical trial data.
The FDA approved Symvess in December 2024 for use in urgent, life-threatening traumatic injuries, despite internal resistance from the agency's own scientists who questioned the product's safety profile and readiness for market.
Internal FDA Dissent Raises Red Flags
The approval process for Symvess has come under scrutiny following reports of substantial opposition within the FDA itself. Dr. Robert E. Lee, a vascular surgeon specializing in gunshot wound treatment, reportedly retired from the FDA last year in protest over the device's approval, according to The New York Times.
Another FDA medical reviewer wrote that the two studies submitted by Humacyte failed to meet "the usual criteria for an adequate and well-controlled trial," raising questions about the evidence supporting the product's approval.
Despite these concerns, the Center for Biologics Evaluation and Research (CBER) greenlit the device, stating that the "benefits outweighed the risks" and describing it as "important progress in addressing a significant unmet medical need" for vascular trauma.
Troubling Clinical Trial Outcomes
The petition from Northeastern researchers, led by Dr. Hooman Noorchashm of the university's School of Law and co-director of the Amy J. Reed Medical Device Safety Collaborative, highlights alarming outcomes from the clinical trials.
Among 54 patients who participated in the study, clinical data revealed:
- Four patient deaths
- Four limb amputations, including one case involving a clot and infection in the artificial vessel
- One patient whom doctors lost track of during follow-up
- Multiple cases of complications after implantation
"It seemed like there were some significant irregularities with respect to clinical trial endpoints and overall outcomes, in addition to the concerns that folks at the FDA have raised," said Noorchashm.
Discrepancies in Reported Success Rates
Adding to the controversy, Humacyte has reportedly claimed an 84% success rate for Symvess in medical journals and investor meetings, while the FDA's own analysis determined the success rate to be only 67%.
The product carries the FDA's most severe warning label—a black box warning—stating that potential failures "can result in life-threatening hemorrhage." While the agency requires ongoing safety monitoring, critics argue the vessel should never have received approval given the uncertainty surrounding its performance.
Military Applications Raise Stakes
The Department of Defense has partnered with the FDA to purchase Symvess for treating wounded military personnel, adding urgency to the safety concerns. Humacyte has already begun marketing efforts targeting hospitals and the military, according to reports.
"It's less about whether the company has to show that its product is more safe and effective than an existing therapy but rather, in this case, the fact that there are people saying this device doesn't even meet the existing standard given the catastrophic risks associated with it," explained David Simon, an associate professor of law at Northeastern with expertise in healthcare law.
Petition Seeks Comprehensive Review
The petition filed by the Northeastern researchers calls for:
- Revocation of Symvess's approval
- A "stringent public expert committee review" of the device's safety data
- Recall of the product
- Sharing of internal data submitted by Humacyte with the Department of Defense
The Amy J. Reed Medical Device Safety Collaborative, a multi-university partnership, focuses on scrutinizing safety risks of new medical devices and analyzing regulatory failures. The group's investigation into Symvess represents one of its efforts to address potential gaps in the medical device approval process.
"Sometimes these investigations morph into citizen petitions, product liability lawsuits or false claims lawsuits," Noorchashm noted.
The Secretary of Health and Human Services has the authority to convene an open advisory committee hearing where independent experts and stakeholders could weigh in on the product's approval and safety profile—a step the petitioners are actively seeking.
