Aliso Viejo, CA, Sept. 30, 2026 (GLOBE NEWSWIRE) -- Terumo Neuro Signs Agreement to Acquire Arsenal Medical – Advancing Next-Generation Liquid Embolic Innovation for Treating Chronic Subdural Hematoma (cSDH)
Proposed acquisition would add NeoCast™, an investigational technology designed for controlled delivery and predictable distal penetration, to Terumo Neuro’s neurovascular portfolio.
Aliso Viejo, Calif. – September 29, 2026 – Terumo Neuro today 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.
For more information, contact:
Rebecca Janzon, Terumo Neuro, Global Director Corporate Communications
Email: Rebecca.janzon@microvention.com
About Terumo Neuro
Terumo Neuro is on a mission to preserve and restore brain health by advancing innovation that changes what's possible in neurovascular care. Working shoulder to shoulder with physicians, customers, and Associates, we turn deep clinical insight into proven, refined solutions that elevate practice and improve patient outcomes — the kind of game-changing impact that redefines neuro-endovascular treatment. Founded in 1997 as MicroVention and acquired by Terumo Corporation in 2006, Terumo Neuro offers a comprehensive portfolio for the treatment of cerebral aneurysms, ischemic stroke, carotid artery disease, and neurovascular malformations. Headquartered in Aliso Viejo, California, our products are sold in more than 70 countries.
For more information, please visit www.terumoneuro.com.
About Terumo Corporation
Terumo (TSE: 4543) is a global medical innovation company. Guided by an unwavering commitment to patients, and driven by the passion of our associates, we strive to fulfill our Group Mission of “Contributing to Society through Healthcare.” Founded in Tokyo in 1921, we provide a comprehensive range of solutions in the fields of therapeutic procedures, hospital operations, and life sciences in more than 160 countries and regions.
About Arsenal Medical
Arsenal Medical is a privately-held, venture-backed, clinical-stage company developing innovative biomaterials to address challenging and underserved medical problems. Its lead product targets neurovascular conditions. The company was founded by academic luminaries Robert Langer and George Whitesides, together with entrepreneur investor Carmichael Roberts, who shared a vision for how materials can transform medical devices. Learn more at www.arsenalmedical.com.
References
- Levitt MR, Hirsch JA, Chen M. Middle meningeal artery embolization for chronic subdural hematoma: an effective treatment with a bright future. J Neurointerv Surg. 2024 Mar 14
- Shankar JJS, Alcock S, Kashani N, et al.; EMMA-Can investigators. Management of Chronic Subdural Hematoma With Adjunctive Embolization of Middle Meningeal Artery: The EMMA-Can Randomized Clinical Trial. JAMA. Published online April 30, 2026
- Mascitelli Justin R, et al.; Current state of the field and recommendations for middle meningeal artery embolization in chronic subdural hematoma: A Report of the SNIS Standards and Guidelines Committee, Endorsed by ANZSNR and ESMINT. Journal of NeuroInterventional Surgery, April 2026
- Next-generation liquid embolic leads to “substantial” cSDH resolution and functional outcome gains. NeuroNews, July 24, 2026
- Arsenal Medical. Treatment with NeoCast, a Next-Generation Liquid Embolic, Results in Substantial Chronic Subdural Hematoma Resolution and Functional Outcome Gains in Final EMBO-02 First-in-Human Results. Press announcement issued July 22, 2026
- U.S. Food and Drug Administration. PMA Supplement Approval Letter: Onyx Liquid Embolic System (LES), P030004/S035. December 8, 2025
Contact Info
Rebecca Janzon
rebecca.janzon@microvention.com
+1 949-685-4391
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