Japan's First Clinical Study of “Exosomes” for the Treatment of Knee Osteoarthritis

Recently NHK News on-line reported the following:

変形性ひざ関節症の治療に「エクソソーム」 国内初臨床研究

2026年2月17日午後6時42分

医療・健康

50歳以上の2人に1人がなるとされる「変形性ひざ関節症」の治療に、組織の再生を促す働きがあるとされる「エクソソーム」という物質が有効かを確かめる国内初の臨床研究を、神奈川県にある病院の研究グループが始めました。

これは神奈川県鎌倉市にある徳洲会湘南鎌倉総合病院の研究グループが、17日会見を開いて発表しました。

変形性ひざ関節症は加齢でひざの軟骨がすり減るなどして、変形や炎症が起きる病気で、国内の患者は50歳以上では2人に1人の割合とされています。

グループは、この病気の治療にエクソソームという物質が有効かを確かめる臨床研究を始め、ヒトの細胞の培養液から採取したエクソソームを1例目の患者に投与したと明らかにしました。

エクソソームは細胞から分泌される物質で、動物実験で軟骨を修復したと報告されるなど、組織の再生を促す働きがあるとされています。

美容などを目的に自由診療で提供するクリニックが増えていますが、グループによりますと、科学的に効果を確認する臨床研究は国内で初めてだということです。

ことし中に5人の患者に投与して安全性を確認するほか、痛みが治まるかやひざが動かしやすくなるかを評価するということです。

湘南鎌倉総合病院の小林修三院長は「高齢者の暮らしに大きく影響する病気なので、今回の研究をきっかけに多くの患者に応用できるようにしたい」と話していました。

Translation

Japan's First Clinical Study of “Exosomes” for the Treatment of Knee Osteoarthritis

February 17, 2026, 6:42 PM

Medicine & Health

A research group at a hospital in Kanagawa Prefecture had begun Japan's first clinical study to test whether “exosomes”, a substance believed to promote tissue regeneration, were effective in treating “knee osteoarthritis”, a condition that was estimated to affect one in two people over the age of 50.

This was announced at a press conference on the 17th by a research group at Tokushukai Shonan Kamakura General Hospital (徳洲会湘南鎌倉総合病院) in Kamakura City (鎌倉市), Kanagawa Prefecture(神奈川県).

Knee osteoarthritis was a disease that caused deformation and inflammation due to the wear and tear of knee cartilage because of aging. It was estimated that in Japan one in two people over the age of 50 suffered from this condition.

The group had begun clinical research to test whether exosomes were effective in treating this disease, and announced that they had administered exosomes extracted from human cell culture medium to the first patient.

Exosomes were substances secreted by cells that were believed to have the ability to promote tissue regeneration, as shown by reports that they could repair cartilage in animal experiments.

While there were an increasing number of clinics offering this treatment for cosmetic purposes, etc., but according to the group, this was the first clinical study in Japan to scientifically confirm their effectiveness.

The drug would be administered to five patients this year to confirm its safety, and to evaluate whether it relieved pain and made knee movement easier.

Shonan Kamakura General Hospital Director Shuzo Kobayashi (小林修三) said, "This is a disease that has a major impact on the lives of the elderly, I hope that this research will inspire this application to many patients. "

So, Japan has begun its first clinical study to test whether “exosomes”, a substance believed to promote tissue regeneration are effective in treating “knee osteoarthritis”, and to evaluate whether they can relieve pain and make knee movement easier. I hope good news will come out from this clinical study.

Note:

1. Exosomes (エクソソーム), ranging in size from 30 to 150 nanometers, are membrane-bound extracellular vehicles (EVs) that are produced in the endosomal compartment of most eukaryotic cells. In multicellular organisms, exosomes and other EVs are found in biological fluids including saliva, blood, urine and cerebrospinal fluid. EVs have specialized functions in physiological processes, from coagulation and waste management to intercellular communication. (Wikipedia)