Medicine with iPS Cells: Research Originating from Japan Finally Bearing Fruit

Editorial

14:49 JST, April 23, 2025

Regenerative medicine, which uses iPS (induced pluripotent stem) cells and other materials to cure diseases for which there have been no treatment methods, is now much closer to practical application. It is hoped that a treatment method will be established at an early stage and it will be used for patients.

Kyoto University Hospital has announced the results of a clinical trial in which nerve cells made from human iPS cells were transplanted into the brains of seven patients with Parkinson’s disease, who then showed improvement in their symptoms. This is a groundbreaking achievement.

Parkinson’s disease is an intractable disease that causes tremors in the limbs and slowness of movement due to a decrease in dopamine, a substance in the brain that is related to the coordination of movement. It is estimated that there are about 290,000 patients in Japan. Symptoms can be suppressed with drugs that increase the volume of dopamine, but there is no fundamental cure.

In the recent clinical trial, the treatment method was effective for some patients and they no longer required assistance. However, there is a need to confirm the effectiveness of the method in trials with a larger number of patients before it can be put into practical use.

But, unlike conventional pharmaceuticals that can be mass-produced such as in the form of pills, the development and quality control of advanced pharmaceuticals using cells and other materials is much more difficult, and large-scale clinical trials also are not easy to conduct.

For this reason, pharmaceutical companies that will manufacture and sell the drug with the cells intend to aim to collect a large amount of data by utilizing the conditional and time-limited approval, or early approval, system that applies to regenerative medicine.

Under this system, unlike the usual procedure in which all clinical trials are completed before full approval and marketing, a drug company first seeks to obtain early approval, which is equivalent to a provisional license, after small-scale clinical trials, and then aims for full approval by collecting data showing treatment effects.

This can be said to be a useful system that encourages technological innovation in the medical field and brings new drugs to patients faster. However, of the five products that were granted early approval separately from the recent clinical trial, the applications of two products were withdrawn due to the failure to prove the efficacy of the drugs, and the remaining three products have not yet received full approval.

Although it is essential to fully verify the safety and efficacy of this product in the recent trial as well, there are high expectations that a path to practical application has been opened.

Prof. Shinya Yamanaka at Kyoto University discovered technologies to generate iPS cells and was awarded the Nobel Prize in 2012. The government has intensively invested funds in iPS research. It seems that the research that has spanned more than a decade is finally bearing fruit.

Recently, research on the use of iPS cells for the treatment of Parkinson’s disease, spinal cord injuries and diabetes has been advancing. For example, a startup from the University of Osaka has applied for approval to manufacture and market cardiomyocyte sheets made from iPS cells to transplant them into patients with heart disease.

It is hoped that collaboration between industry and academia will be strengthened to realize long-awaited treatments with iPS cells originating from Japan.

(From The Yomiuri Shimbun, April 23, 2025)