RADIANT Pivotal Trial Approved for Arsenal’s NeoCast Liquid Embolic for Chronic Subdural Hematoma

May 26, 2026—Arsenal Medical announced that the FDA granted investigational device exemption approval for the RADIANT pivotal trial. The trial will evaluate the company’s NeoCast for symptomatic subacute and chronic subdural hematoma (cSDH).

Arsenal stated that NeoCast is a solvent-free, nonadhesive liquid embolic biomaterial under development. It is designed to achieve pain-free, predictable distal penetration of the middle meningeal artery (MMA). NeoCast’s shear-thinning properties are intended to allow the material to reach small vessels and occlude blood flow to tumors and diseased tissues.

According to the company, RADIANT is a prospective, randomized, multicenter study that will evaluate NeoCast adjunctive to surgery. Neocast will be compared with the FDA-approved Onyx liquid embolic system (Medtronic) for cSDH. The trial is expected to enroll approximately 360 patients in a 2:1 randomization at up to 35 sites in the United States and Australia.

Charles Matouk, MD, neurosurgeon at Yale New Haven Hospital in New Haven, Connecticut, serves as Coprincipal Investigator of the RADIANT trial.

“cSDH is becoming one of the most common conditions we manage in neurointervention,” commented Dr. Matouk in Arsenal’s press release. “RADIANT will evaluate NeoCast as a potentially differentiated liquid embolic designed to provide predictable distal penetration while minimizing patient discomfort.”

Arsenal noted that NeoCast demonstrated feasibility in the EMBO-01 and EMBO-02 first-in-human studies. EMBO-01 evaluated NeoCast in preoperative embolization of hypervascular brain tumors. EMBO-02 is studying MMA embolization for cSDH. Complete EMBO-02 results will be released later this year, advised the company.