EMBO-02 FIH Study of Arsenal’s NeoCast Liquid Embolic Meets Endpoints in Treatment of cSDH

July 22, 2026—Arsenal Medical announced late-breaking results from the EMBO-02 first-in-human (FIH) clinical study, which is evaluating the company’s NeoCast liquid embolic for middle meningeal artery embolization (MMAe) to treat chronic subdural hematoma (cSDH).

The company stated that NeoCast is a next-generation, shear-responsive, solvent-free, nonadhesive liquid embolic that is engineered to reach distal microvasculature without causing pain.

According to the company, the EMBO-02 study met its primary feasibility and safety endpoints with positive clinical outcomes in the late-breaking results presented by David J. Fiorella, MD, at the 23rd annual meeting of the Society of Neurointerventional Surgery.

As noted in the company’s press release, the EMBO-02 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.

Arsenal Medical reported that at final follow-up, 96% (23/24) of patients in the study achieved at least 50% volume resolution, and 75% (18/24) had complete hematoma resolution.

In functional outcomes, 79% of patients improved over baseline modified Rankin Scale and quality-of-life measures through 180 days. Notably, 79% (19/24) of patients were treated with embolization alone, and 10 patients were treated without general anesthesia, stated the company.

“These NeoCast results are encouraging in ways that could have meaningful implications for both physicians and patients,” commented EMBO-02 study investigator Tim Phillips, MBBS, in the company’s press release. Dr. Phillips is an interventional neuroradiologist at the Neuro-Intervention and Imaging Service of Western Australia, Sir Charles Gairdner Hospital in Perth, Australia.

Dr. Philips continued, “In my experience, NeoCast demonstrated highly predictable distal penetration, allowing effective embolization without the need to advance the microcatheter deep into the target vasculature, which simplified and streamlined the procedure. Equally important, because NeoCast is free of toxic solvents, patients experienced a virtually pain-free injection. The ability to perform middle meningeal artery embolization without sedation represents a meaningful advancement in patient care.”

In May 2026, Arsenal Medical announced FDA approval of an investigational device exemption for the RADIANT prospective, randomized, multicenter study. The trial will compare NeoCast to the Onyx LES (Medtronic), a liquid embolic system that is FDA-approved for the treatment of cSDH in conjunction with surgery.

“EMBO-02 has given us a strong foundation to take the next step with NeoCast,” stated Dr. Fiorello, who is a neuroradiologist at Stony Brook University Hospital in Stony Brook, New York, and serves as the medical monitor of both the EMBO-02 and RADIANT studies. “With RADIANT, we will now evaluate those insights in a rigorous, prospective, randomized, multicenter pivotal trial. There will be significant interest in next-generation embolics that can reliably achieve the level of robust distal occlusion that NeoCast demonstrated in EMBO-02 as the field of neurointervention manages this patient population and evolves new care pathways.”