Arsenal’s NeoCast Liquid Embolic Studied in EMBO-02 Trial

July 22, 2025—Arsenal Medical recently announced findings from the EMBO-02 clinical study evaluating NeoCast, the company’s next-generation, shear-responsive liquid embolic treatment in patients with chronic subdural hematoma (cSDH) using middle meningeal artery embolization (MMAe). The solvent-free, nonadhesive liquid embolic biomaterial is designed to preferentially reach distal microvasculature without inducing pain, noted the company.

The late-breaking data were presented at SNIS 2025, the Society of Neurointerventional Surgery annual meeting.

According to the company, the study showed that all patients met primary safety and feasibility endpoints. Separate late-breaking results demonstrated that NeoCast can be administered painlessly and resulted in rapid hematoma resorption. The EMBO-02 study has enrolled 15 patients with cSDH at three sites in Australia. The initial cohort (n = 10) allowed either general anesthesia or conscious sedation, while the second cohort (n = 5) specified the use of conscious sedation, stated the company.

Arsenal Medical reported the following highlights from the data:

• 87% of patients underwent embolization without adjunctive surgery
• 100% target vessel occlusion was achieved with no nontarget embolization
• No NeoCast-related adverse events occurred
• In cohort 1, 60% and 90% of patients had complete hematoma resolution at 3 and 6 months, respectively
• In cohort 1, > 80% of patients had clinical outcome measures (modified Rankin Scale, Visual Analog Scale, and Markwalder scores) that were improved or unchanged from baseline
• In cohort 2, MMAe with NeoCast was completed under conscious sedation
• In cohort 2, no patients reported pain during the injection or increased headache 24 hours postembolization

Lee-Anne Slater, MBBS MMed, who is the EMBO-02 principal investigator, and Tim Phillips, MBBS, commented on the findings in the company’s press release.

“NeoCast’s unique material characteristics have translated from preclinical studies to the EMBO-01 first-in-human study in hypervascular brain tumors, and now to the treatment of chronic subdural hematoma in EMBO-02,” stated Dr. Slater. “Results from these studies demonstrate the potential of NeoCast to provide deep distal penetration in multiple clinical scenarios and suggest benefits in speed of hematoma resolution for patients suffering from chronic subdural hematoma.” Dr. Slater is an interventional neuroradiologist at Monash Health in Clayton, Australia.

Dr. Phillips added, “NeoCast is truly a next-generation liquid embolic agent. The ease of use, controllability, and the lack of pain during or after the injection are such differentiating factors for NeoCast over currently available liquid agents.” Dr. Phillips is an interventional neuroradiologist at the Neuro-Intervention and Imaging Service of Western Australia, Sir Charles Gairdner Hospital in Perth, Australia.

Arsenal Medical stated that the EMBO-02 study is an open-label, multicenter, prospective, externally monitored, core lab-adjudicated, feasibility clinical trial. The primary safety endpoint is device-related disabling stroke or neurological death within 30 days of embolization. The primary feasibility endpoint is the successful injection of NeoCast, resulting in complete occlusion at, or distal to, the point of injection.