Bone Marrow Stem Cells for Brain Injury: AKUUGO Launches in Japan with Insurance Coverage, and New TBI Clinical Results

Summary — Bone marrow stem cell therapy for brain injury has reached routine care in Japan. AKUUGO intracerebral implantation injection (generic name vandefitemcel), a regenerative medicine product developed by SanBio, was added to Japan's public health insurance price list on May 20, 2026, and sales began the next day, May 21. Made from mesenchymal stem cells taken from the bone marrow of healthy donors, it targets chronic motor paralysis after traumatic brain injury caused by traffic accidents or falls. In June 2026, a team at UTHealth Houston in the United States also published results in the journal Brain from 24 patients with chronic traumatic brain injury who received their own adipose-derived stem cells intravenously. This article explains both reports and what they mean.

Motor paralysis that remains after traumatic brain injury

Traumatic brain injury (TBI) is damage to brain tissue caused by a strong blow to the head, for example in a traffic accident, a fall or a sports accident. Even after the acute phase, weakness or slowed movement of the arms and legs often persists for a long time. According to SanBio, about 43% of hospitalized TBI survivors in the United States are estimated to live with long-term motor impairment. The Japanese business magazine Toyo Keizai (August 13, 2026) reported that Japan has about 60,000 patients in the chronic phase, of whom about 12,000 have lasting disability.

Standard care today centers on rehabilitation, mainly physical and occupational therapy. In the chronic phase, about six months after the injury when recovery has largely plateaued, medication and rehabilitation alone often cannot raise function further. This is why cell therapies that rebuild a healing environment around damaged nerve tissue have drawn attention. Bone marrow stem cell research in stroke is covered on our stroke stem cell research page.

AKUUGO in Japan: the first bone marrow stem cell product for brain injury on sale

AKUUGO is made by culturing mesenchymal stem cells (MSCs) obtained from the bone marrow of healthy adult donors and introducing a gene for the human Notch-1 intracellular domain to strengthen their ability to support nerve regeneration. The company explains that the cells are expected to release growth factors such as FGF-2 that help nerve cells grow and differentiate. The adult dose is 5 million viable cells (300 μL), delivered by stereotactic surgery along three paths around the injured area through a single small opening in the skull.

Japan's Ministry of Health, Labour and Welfare granted AKUUGO conditional, time-limited approval on July 31, 2024. The company then submitted additional data confirming that commercial products match the quality of the trial product, and received a partial change approval in December 2025 that cleared the way for shipment. On May 13, 2026, the Central Social Insurance Medical Council approved a price of 72,716,528 yen; the product was listed on May 20 and went on sale on May 21. The company is expanding supply step by step, starting with hospitals that took part in the clinical trials, and planned first shipments between August 2026 and January 2027.

Patient criteria are defined: at least six months since the injury with stabilized motor impairment, an injured area visible on MRI, and moderate or more severe symptoms. According to Yakuji Nippo (May 25, 2026), a care system is being organized in which facilities for MRI evaluation, implantation surgery and post-implantation rehabilitation work together.

Motor improvement confirmed in an international phase 2 trial

The approval was based on the international phase 2 TBI-01 trial conducted in the United States, Japan and Ukraine. Patients were randomized, neither patients nor evaluators knew the group assignment (double-blind), and the control group received sham surgery without cells. According to SanBio's announcement of May 21, 2026, at 24 weeks the Fugl-Meyer Motor Scale (FMMS) score for arm and leg movement rose by an average of 8.3 points (SD 10.6) in the cell group (46 patients) and by 2.3 points (SD 4.7) in the sham group (15 patients). The difference was statistically significant (p=0.0401).

The result shows that motor function can still improve in a period long considered to be after recovery has stopped. Conditional, time-limited approval is a system in which effectiveness is confirmed again with real-world data within a set period. For full approval, SanBio plans a post-marketing study of 42 patients (28 AKUUGO, 14 control), involving 5 to 7 surgical facilities and 10 to 21 rehabilitation facilities. A case that went through the same system toward full approval in spinal cord injury is described in our article on bone marrow stem cells for spinal cord injury (Stemirac).

A US study: intravenous autologous adipose stem cells in 24 patients

Results from an approach that delivers cells through a vein, without surgery, have also appeared in the United States. The team of Professor Charles S. Cox, Jr. at UTHealth Houston gave 24 adults injured at least six months earlier three intravenous infusions of 200 million mesenchymal stem cells from their own adipose tissue (HB-adMSCs), 14 days apart over six weeks. This open-label phase I/IIa study followed patients for one year after the last infusion. The results were published in the neuroscience journal Brain in June 2026, and Hope Biosciences, which supplied the cells, announced them on June 23.

On PET imaging the team found reduced density of immune cells in brain regions linked to depression, fatigue and pain. Over the same period, measures of depression, fatigue and pain improved, and MRI measures of brain microstructural integrity also improved. No serious treatment-related adverse events were reported. Dr. Cox said the results justify moving to larger controlled trials, and a double-blind, placebo-controlled phase II trial in 51 patients aged 18 to 55 is being prepared.

Stages of bone marrow stem cell research for brain injury and next steps

The two studies show different paths. AKUUGO places donor bone marrow stem cells directly near the injured area inside the brain; after a controlled phase 2 trial reported motor improvement, it went on to approval and insurance coverage in Japan. The US study infuses the patient's own adipose stem cells into a vein and, in an early uncontrolled trial, reported improvements in brain inflammation markers and in mood and pain symptoms. Next, Japan's post-marketing study and the US placebo-controlled trial will confirm these results in more patients.

SanBio has stated that it agreed with the US Food and Drug Administration (FDA) on the design of a phase 3 trial in chronic TBI, and that it plans to begin clinical trial consultations with Japan's Pharmaceuticals and Medical Devices Agency (PMDA) for chronic ischemic stroke. Japanese research giving bone marrow stem cells intravenously to stroke patients is covered in our article on intravenous bone marrow stem cells for stroke.

Where AKUUGO sits in Japan's system

Stem cell medicine in Japan is regulated along two tracks. Approved "regenerative medicine products" such as AKUUGO, approved under the Pharmaceuticals and Medical Devices Act, are used in insured care, while cell therapies that hospitals carry out under their own plans go through committee review and submission to the Ministry under the Act on the Safety of Regenerative Medicine. AKUUGO belongs to the first track, and surgery and rehabilitation are carried out together at facilities that meet set requirements. Both tracks are summarized in our timeline of regenerative medicine in Japan.

Frequently asked questions

Who is eligible for bone marrow stem cell therapy for brain injury?

AKUUGO, approved in Japan, is for chronic motor paralysis caused by traumatic brain injury. The criteria are at least six months since the injury with stabilized symptoms, an injured area visible on MRI, and moderate or more severe symptoms. Whether it is suitable for a given patient is decided by the treating medical team who examines the patient.

How is AKUUGO given?

A single small opening is made in the skull, and the cell suspension is divided among three sites around the injured area using stereotactic surgery. Rehabilitation continues after implantation while changes in motor function are followed.

Are the same stem cells used for stroke?

AKUUGO is approved for traumatic brain injury. SanBio is preparing a clinical trial in chronic ischemic stroke, and in Japan stroke research with other bone marrow stem cell products is also continuing.

Conclusion

AKUUGO, which went on sale in Japan in May 2026, is the first regenerative medicine product sold in Japan for traumatic brain injury, and marks the entry of bone marrow stem cell therapy for brain injury into insured care. In the international phase 2 trial, motor scores improved more in the cell group than in the sham group, and in the United States a study of intravenous autologous adipose stem cells reported improvements in brain inflammation markers and symptoms. Confirmatory studies in more patients are under way for both. The suitability and risks of treatment are judged by the treating medical team.

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