FDA Approves First Acellular Tissue Vessel Therapy for Extremity Vascular Trauma

Credit: FDA

The FDA has approved Humacyte’s acellular tissue engineered vessel-tyod (ATEV) therapy, under the name Symvess, for use in adults as a vascular conduit for extremity arterial injury when urgent revascularization is needed to avoid imminent limb loss, and when autologous vein graft is not feasible.¹

“Today’s approval provides an important additional treatment option for individuals with vascular trauma, produced using advanced tissue engineering technology,” Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research (CBER), said in a statement.¹ “The FDA remains committed to facilitating the development of innovative products that offer potentially life-saving benefits for patients with severe injuries.”

The therapy is indicated to help provide revascularization when autologous vein grafting or implantation of a synthetic graft is not feasible. The ATEV is composed of human extracellular matrix (ECM) proteins typically found in human blood vessels and is a sterile, acellular tissue engineered vessel. Human vascular smooth muscle cells derived from human aortic tissue are utilized in the ATEV’s tissue engineering process.

“Currently available treatment options are limited for vascular trauma, which can lead to severe and potentially life-threatening complications,” Nicole Verdun, MD, director of the Office of Therapeutic Products in CBER, added.¹ “Today’s decision to approve a new therapeutic product based on novel medical technology represents important progress in addressing a significant unmet medical need.”

The ATEV was approved based on data from the pivotal Phase 2/3, prospective, single arm, multicenter V005 study in patients with life- or limb-threatening vascular trauma, as well as real-world evidence from the treatment of wartime injuries in Ukraine under a humanitarian aid program.

In the study, 54 patients received the ATEV to repair an arterial vessel in the extremity. Of these patients, 36 (67%) retained primary patency (blood flow present without any intervention) and 39 (72%) retained secondary patency (at least one intervention required to maintain blood flow) at day 30. Within the first 30 days, 5 patients (9%) underwent amputation of the treated limb, and by the end of the study at month 36, 8 (15%) patients underwent amputation of the treated limb.²

The ATEV has been used to repair traumatic injuries including car accidents, gunshot wounds, blast wounds, and industrial accidents by vascular and trauma surgeons in Level 1 Trauma centers throughout the United States, Israel, and Ukraine, with high rates of patency, or blood flow, and low rates of amputation and infection. These findings were published in JAMA Surgery in November 2024.³

“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,” investigator Charles J. Fox, MD, FACS, Director of Vascular Surgery, University of Maryland Capital Region, said in a statement.² “SYMVESS is perfectly sized to treat most injuries, has excellent handling properties, and reduces time necessary to save both life and limbs. The Humacyte team has responsibly and scientifically solved a major clinical problem that I believe will reduce the amputation rate for traumatic vascular injury. They should be congratulated on an accomplishment that will undoubtedly advance our specialty to the next level.”

Common adverse events (AEs) include thrombosis, fever, pain, and anastomotic stenosis. Serious AEs that may occur include graft rupture, anastomotic failure and thrombosis. Transmission of infectious diseases or infectious agents can occur from the human donor cells and human and bovine reagents used in manufacturing the ATEV, although donor eligibility requirements are in place to prevent the transmission of infectious diseases.

“The FDA approval of SYMVESS will make it the preferred conduit for complex vascular injuries, and particularly those at risk for infection,” investigator Ernest E. Moore, MD, FACS, Director of Research, Ernest E. Moore Shock Trauma Center at Denver Health, added.² “I look forward to using SYMVESS in my practice.”

The ATEV previously also received Priority Review and Regenerative Medicine Advanced Therapy (RMAT) designation from the FDA, and is also designated as a Priority Product by the U.S. Department of Defense, which allowed expedited development under Public Law 115-92 for a product that may diagnose, treat or prevent serious or life-threatening diseases or conditions facing American military personnel.

REFERENCES
1. FDA Approves First Acellular Tissue Engineered Vessel to Treat Vascular Trauma in Extremities. News release. FDA. December 20, 2024. https://www.fda.gov/news-events/press-announcements/fda-approves-first-acellular-tissue-engineered-vessel-treat-vascular-trauma-extremities#

2. Humacyte Announces FDA Approval of SYMVESS™ (acellular tissue engineered vessel-tyod) for the Treatment of Extremity Vascular Trauma. News release. Humacyte. December 19, 2024. https://uk.finance.yahoo.com/news/humacyte-announces-fda-approval-symvess-034700671.html

3. Moore EE, Curi M, Namias N, et al. Bioengineered Human Arteries for the Repair of Vascular Injuries. JAMA Surg. Published online November 20, 2024. doi:10.1001/jamasurg.2024.4893