Terumo Neuro to Acquire Arsenal Medical

October 1, 2026—Terumo Neuro announced that it has signed an agreement to acquire Arsenal Medical Inc., which is developing NeoCast, a 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 and advance its strategy to provide differentiated neurovascular technologies. The proposed transaction is subject to customary closing conditions. Financial terms of the agreement were not disclosed, noted the press release.

According to Terumo Neuro, NeoCast is a solvent-free, nonadhesive biomaterial intended for embolization of the middle meningeal artery (MMA). It is an investigational device and is not approved for commercial sale in the United States.

Terumo Neuro noted that Arsenal Medical has advanced NeoCast through its first-in-human clinical experience in the EMBO-02 study for MMA embolization to treat cSDH.

In July 2026, Arsenal Medical announced that late-breaking results from the EMBO-02 trial were presented by David J. Fiorella, MD, at the 23rd annual meeting of the Society of Neurointerventional Surgery.

Terumo Neuro advised that the EMBO-02 findings are preliminary and provide supporting clinical context for the prospective, randomized, multicenter RADIANT pivotal study comparing NeoCast to the Onyx liquid embolic system (Medtronic) for the treatment of symptomatic subacute and chronic subdural hematoma adjunctively with surgery.

In May 2026, Arsenal Medical announced FDA investigational device exemption approval for the RADIANT trial. Enrollment in the trial has begun, stated Terumo Neuro.

Terumo Neuro CEO Carsten Schroeder commented on the pending acquisition of Arsenal Medical in the press release.

“NeoCast represents a compelling opportunity to advance what could be a game-changing innovation in the treatment of chronic subdural hematoma,” stated Schroeder. “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.”