We are pleased to announce that we submitted today the application to the Ministry of Health, Labour and Welfare (MHLW) to expand the approved use of Borofalan (10B) (development code: SPM-011; hereinafter “the Product”), a drug used in BNCT (Boron Neutron Capture Therapy) to treat recurrent meningioma.
The application is based on the positive results from a physician initiated*1 Phase II randomized controlled trial*2 conducted at Osaka Medical and Pharmaceutical University.
In this study, the primary endpoint – progression free survival (PFS)*3 as assessed by an independent review committee – was 14.4 months (95% CI: 7.9–26.4) in the BNCT treatment arm, compared with 1.4 months (95% CI: 1.0–9.0) in the control arm receiving the best physician selected available treatment. This difference was statistically significant (p = 0.0157, log rank test).
Regarding the secondary endpoint of objective response rate (ORR; complete response (CR) + partial response (PR)), a response rate of 27.3% was observed in the BNCT treatment arm, whereas no responses were observed in the control arm. Furthermore, overall survival data demonstrated favorable outcomes in the BNCT arm, with a 1‑year survival rate of 100% and a 2‑year survival rate of 90.9%, supporting the efficacy and safety of the Product.
The meninges are thin layers of tissue that protect the brain and spinal cord, and meningioma is a type of brain tumor that arises from one of these inner layers. While meningiomas are often benign (WHO Grade 1), high grade meningiomas (WHO Grades 2 and 3) can infiltrate deeply into the brain, cerebral vasculature, and skull, and are prone to repeated recurrence. In some cases, metastasis to other organs such as the lungs may also occur.
For recurrent disease, surgical resection and external‑beam X‑ray radiotherapy are typically employed; however, their therapeutic effectiveness is limited. In Japan, no pharmaceutical products are currently approved for the treatment of meningioma, and no effective standard therapy has been established.
According to estimates based on the Ministry of Health, Labour and Welfare’s “Regional Cancer Registry” (2005–2008) and the “Japan Brain Tumor Registry,” the annual incidence of cancers of the brain and central nervous system is approximately 5,000 cases, of which meningiomas account for about 23.8%. This corresponds to an estimated 1,200 new cases of meningioma per year. The “National Cancer Registry” (2021) similarly reports 5,741 cases of brain and central nervous system cancers, supporting the validity of these estimates. Furthermore, based on the Ministry’s “Patient Survey 2023,” the total number of patients living with meningioma (prevalence) in Japan is estimated to be fewer than 23,500.
In this context, the Product received Orphan Drug designation from the MHLW in September 2024 for the treatment of recurrent meningioma, a condition affecting fewer than 50,000 patients in Japan. This designation, which aims to promote the research and development of therapies for rare diseases, granted various incentives, including eligibility for government research funding support. Furthermore, in February 2026, the Company received an assessment report from the Pharmaceuticals and Medical Devices Agency (PMDA) indicating that the Product qualifies as a priority review item under the Orphan Drug framework. Based on this determination, the Product is expected to undergo a shortened review period compared with a standard application.
*1 Investigator-initiated trial
An investigator-initiated trial is a clinical trial conducted by a physician who plans and designs the clinical trial for the purpose of obtaining approval for the manufacture and sale of a drug, submits a clinical trial plan notification, and then conducts the trial. The obtained clinical data is passed on to the pharmaceutical company that provided the investigational drug and used in the drug’s regulatory approval application. This trial was conducted with support from the Japan Agency for Medical Research and Development (AMED), a national research and development agency.
*2 Randomized controlled trial
In a randomized controlled trial, the participants are divided at random into at least two groups. One group is treated with the conventional treatment, and the other group is treated with the new therapy, and the effects of the treatments are verified by observing and comparing the health conditions of the subjects after the treatment.
*3 Progression-free survival
Progression-free survival is one indicator to measure the effectiveness of cancer treatment. It shows the period after treatment until progression or recurrence of cancer, or the time until the death of the patient.