Japan is widely applying stem cell technology to the exploration of treatments for various intractable diseases such as retinal disorders, Parkinson's disease, spinal cord injuries, and diabetes, gradually advancing these therapies from the laboratory to the market.

Treatment of Eye and Neurological Diseases: Japanese scientists have successfully cultivated retinal cells and neurons using induced pluripotent stem cells (iPS cells). Masayo Takahashi, an ophthalmologist in Kobe, transplanted iPS cell-derived retinal cells into the eyes of patients with macular degeneration. These cells survived for ten years, effectively preventing further loss of vision. In the neurological field, Professor Jun Takahashi's team at Kyoto University injected iPS cell-derived neurons into the brains of patients with Parkinson's disease. After the transplantation, symptoms such as tremors and rigidity significantly improved, and some patients were able to live independently.

Exploring new treatments for diabetes: Kyoto University Hospital recently began a clinical trial in which insulin-secreting cells, cultured from healthy donor iPS cells, are formed into sheets and transplanted into the abdomen of patients with type 1 diabetes. Researchers aim to make this treatment practical by 2030.

Industry Oversight and Future Prospects: To accelerate the launch of regenerative medicine products, Japan introduced a conditional approval system in which products are approved after proving to be safe and effective without major safety issues. Although there are concerns that the approval process may be too fast, companies like Sumitomo Pharma have built dedicated iPS cell product manufacturing facilities to meet future demands. More than 60 clinical trials involving iPS cells are being conducted worldwide, with nearly one-third taking place in Japan.