Instylla's Embrace Hydrogel Embolic System Wins Expanded FDA Approval for Peripheral Arterial Bleeds in Vessels Up to 6 mm, With 90% Clinical Success in a 130-Patient Trial
Instylla, Inc., a Massachusetts-based medical device company, announced on October 29 that the U.S. Food and Drug Administration (FDA) has approved an expanded indication for its Embrace Hydrogel Embolic System (HES) to include embolization of peripheral arterial bleeds in vessels up to 6 mm.
The system first received FDA premarket approval (PMA) in August 2025 for embolization of hypervascular tumors in peripheral arteries up to 5 mm, and is commercially available in the United States. With the expansion, it becomes the first and only liquid embolic approved for both peripheral arterial bleeds and hypervascular tumors.
The approval was based on the HALT study, a prospective, multicenter, single-arm trial that enrolled 130 patients with peripheral arterial bleeds at 22 U.S. sites. Embrace HES met both prespecified primary endpoints, with 100% freedom from major adverse events and 90.0% clinical success, defined as no rebleeding from the target lesion, through 30 days.
Suvranu Ganguli, MD, Chief of Interventional Radiology at Boston Medical Center and principal investigator of the HALT study, said treating an arterial bleed requires an embolic solution that can reach the source of bleeding while providing precise control, and that Embrace HES allows either distal or proximal embolization with a single agent while maintaining microcatheter access after embolization, unlike many currently available liquid embolics.
Hemorrhage is the leading cause of potentially preventable death after trauma, the company noted, and arterial bleeding also arises from non-traumatic sources such as non-variceal upper gastrointestinal bleeding, solid-organ bleeds and tumors. Embrace HES is a water-based polyethylene glycol hydrogel whose non-adhesive design eliminates the possibility of catheter entrapment, is coagulation independent, and liquifies via hydrolysis over approximately 11 months.
Sean Boyle, CEO of Instylla, said patients facing complex vascular conditions need more options, and that with approvals now in both interventional oncology and peripheral hemostasis the company is building a platform for further vascular conditions.
Source: GSM · USA (original Chinese edition)
Photo: 图：心导管实验室内的导管操作实景（资料图，与介入栓塞治疗题材相关）。Navy Medicine 图，公共领域，经 Wikimedia Commons。Photo: A catheterization procedure in a hospital cath lab (file photo). Navy Medicine, public domain, via Wikimedia Commons.
