Humacyte, Inc. has received FDA approval for SYMVESS, an acellular tissue-engineered vessel (ATEV) for use in adults with extremity arterial injuries requiring urgent revascularization when an autologous vein graft is not feasible. This first-of-its-kind bioengineered human tissue offers a new option for vascular surgeons treating severe trauma cases, potentially reducing amputation rates and improving patient outcomes. The approval marks a significant milestone in regenerative medicine and provides a readily available alternative to traditional grafting methods.
Clinical Trial Success and Real-World Evidence
The FDA's decision was supported by positive results from the V005 pivotal Phase 2/3 clinical study and real-world evidence from treating wartime injuries in Ukraine. The research combined data from 51 civilian patients at trauma centers in the U.S. and Israel and 16 military patients in Ukraine. Results published in JAMA Surgery on November 20, 2024, indicated that at 30 days post-implantation, approximately 91.5% of the ATEVs remained open and functioning, compared to 78.9% for synthetic grafts in previous studies. The amputation rate was also significantly lower at 4.5%, compared to 24.3% for synthetic grafts. Furthermore, less than 1% of the bioengineered vessels became infected, compared to 8.4% for synthetic options.
Advantages of SYMVESS
SYMVESS offers several advantages over traditional autologous vein grafts, which involve harvesting a vein from the patient's own body. According to Michael Curi, chief of vascular surgery at Rutgers New Jersey Medical School, "If we had two artery replacements that worked equally as well, one you could use straight from a box and one that took 30 minutes to harvest from someone's leg, obviously you'd much rather use the one that was available immediately." The off-the-shelf availability of SYMVESS can save valuable surgical time in trauma cases where rapid restoration of blood flow is critical.
Additionally, SYMVESS has demonstrated superior infection resistance compared to synthetic grafts. The bioengineered vessels are grown in a lab from cultured human cells and then treated to prevent immune rejection. Once implanted, the patient's own cells gradually populate the vessel, making it more resistant to infection.
Expert Opinions
Charles J. Fox, MD, FACS, Director of Vascular Surgery at the University of Maryland Capital Region and a clinical investigator in the V005 clinical trial, stated, "The approval of a vascular conduit that resists infection and remodels into native arteries is an extraordinary technological advancement that will have a huge impact on the quality of trauma care around the world." He added that SYMVESS is perfectly sized to treat most injuries, has excellent handling properties, and reduces time necessary to save both life and limbs.
Rishi Kundi, MD, Surgical Critical Care, Vascular Surgery, University of Maryland Medical System, believes that SYMVESS will revolutionize vascular trauma care and be profoundly beneficial to patients. He anticipates that SYMVESS will allow reconstructions that are currently impracticable because of contamination and infection and will make reconstructions that are now performed with prosthetic or even biologic grafts more successful.
Safety Information
The FDA approval of SYMVESS includes a boxed warning regarding graft failure, emphasizing that loss of SYMVESS integrity due to mid-graft rupture or anastomotic failure can result in life-threatening hemorrhage. The product label also includes contraindications, warnings, and precautions related to graft rupture, anastomotic failure, thrombosis, and transmission of infectious diseases. The most common adverse reactions reported in clinical trials were vascular graft thrombosis, pyrexia (fever), and pain.
Future Applications
While the current FDA approval is limited to vascular trauma, researchers are exploring the use of SYMVESS in other applications, such as dialysis patients and arterial reconstruction. This broader application could address a significant medical need, as many patients require multiple vascular procedures over their lifetime. Laura Niklason, M.D., Ph.D., Founder and Chief Executive Officer of Humacyte, stated that the FDA's full approval of SYMVESS is a transformational event for the Company and their bioengineering technology platform and that they believe SYMVESS provides a new means of treating patients with devastating arterial injuries, which is a population that has not benefited from substantial innovation in decades.
