Terumo Neuro announced that it has signed an agreement to acquire Arsenal Medical Inc., a privately held, clinical-stage biomaterials company developing NeoCast™, an investigational next-generation liquid embolic technology for the treatment of chronic subdural hematoma (cSDH). Upon completion, the proposed acquisition would expand Terumo Neuro’s liquid embolic portfolio, advance its strategy to bring differentiated neurovascular technologies to physicians and patients, and support its continued focus on innovations to preserve and restore brain health.

“NeoCast represents a compelling opportunity to advance what could be a game-changing innovation in the treatment of chronic subdural hematoma,” said Carsten Schroeder, CEO, Terumo Neuro. “As MMA embolization emerges as an important new treatment option, this purpose-developed, next-generation liquid embolic technology has the potential to make a meaningful impact for physicians and patients, while supporting our mission to preserve and restore brain health. We are impressed by the progress Arsenal Medical has made and look forward to combining our global neurovascular expertise with its differentiated technology platform following the close of the transaction.”

cSDH is a significant and growing neurological condition, particularly among aging populations. The condition may cause cognitive decline and disability, has been described as a potential cause of reversible dementia, and can be associated with substantial mortality within one year. While surgical drainage remains a common treatment approach, recurrence after surgery continues to be a clinical challenge. Middle meningeal artery embolization has emerged as a promising adjunctive or alternative approach by targeting the vascular pathology believed to contribute to hematoma persistence and recurrence.1,2,3

Arsenal Medical has developed NeoCast, a next-generation, solvent-free, non-adhesive biomaterial intended for embolization of the middle meningeal artery (MMA). It is engineered for controlled delivery and predictable distal penetration, without solvents or adhesives associated with many embolic devices. Arsenal Medical has advanced NeoCast through first-in-human clinical experience in cSDH and recently received U.S. Food and Drug Administration (FDA) Investigational Device Exemption (IDE) approval for RADIANT, a pivotal randomized, multicenter study evaluating NeoCast adjunctively with surgery for symptomatic subacute and chronic subdural hematoma.4 The first patients have been enrolled in RADIANT.

Final results from the EMBO-02 first-in-human study showed that NeoCast met its primary feasibility and safety endpoints, with 96% of subjects achieving at least 50% hematoma volume reduction and 75% achieving complete hematoma resolution at final follow-up. Notably, 79% of 24 patients were treated with embolization alone, and 10 subjects were treated without general anesthesia.4

The study also reported functional outcome improvements, with 79% of patients demonstrating better functional status based on mRS and quality-of-life measures compared with baseline through 180 days. These findings are preliminary and provide supporting clinical context as NeoCast advances into RADIANT, a prospective, randomized, multicenter pivotal study comparing NeoCast to Onyx LES for the treatment of symptomatic subacute and chronic subdural hematoma adjunctively with surgery.5,6

“Arsenal Medical was founded on the idea that advanced materials can transform the way challenging medical conditions are treated,” said Upma Sharma, PhD, President and CEO, Arsenal Medical. “NeoCast is a powerful example of that vision. It was designed to provide physicians with controlled delivery and consistent distal penetration without the use of solvents or adhesives. Terumo Neuro’s leadership in neurovascular innovation makes it the ideal organization to help realize the full potential of  NeoCast through its next stage of development following the close of the transaction.”

NeoCast is an investigational device and is not approved for commercial sale in the United States. The proposed transaction is subject to customary closing conditions. Financial terms of the agreement were not disclosed.