US clinical trial to transplant pig kidney into patient; kidney functions for up to 270 days

Recently NHK News on-line reported the following:

米 ブタの腎臓を患者に移植する治験 腎臓は最長で270日余機能

2026年2月15日午後10時49分

医療・健康

アメリカの病院などが進めている、ブタの腎臓を患者に移植する治験に携わる日本人医師が15日、都内で最新の経過を発表し、移植した腎臓は最も長い患者で270日余り機能したと報告しました。

これは15日、東京 千代田区で開かれたシンポジウムで、アメリカ・マサチューセッツ総合病院の河合達郎医師が発表しました。

シンポジウムで河合医師は、重い腎不全の患者にブタの腎臓を移植する手術をこれまで4人に行い、移植した腎臓は、最も長い患者で271日間機能して透析が必要ない状態だったと報告しました。

この患者はその後腎臓のドナーが見つかり、移植を受けて回復したということです。

また、ほかの3人のうち、1人は別の病気で死亡し、残りの2人は今も移植したブタの腎臓が機能しているということで、河合医師らは今後も手術を行いアメリカでの承認を目指すとしています。

動物の臓器などを治療のために移植する「異種移植」をめぐっては、ドナーの不足を背景に、国内でもブタの腎臓を移植する治験の準備を進める動きが出ています。

シンポジウムでは国立成育医療研究センターの神里彩子部長らが異種移植への理解について国内の3200人余りにアンケートした結果も報告され、全体の52.9％が異種移植を知らず、勧められた場合抵抗感があるとする回答も77％に上ったと紹介されました。

河合医師は、「日本ではドナーが圧倒的に足りず、移植を諦めている人が多い。われわれの治験の結果も参考にしてもらい、国内での実施について議論してほしい」と話していました。

Translation

US clinical trial to transplant pig kidney into patient; kidney functions for up to 270 days

February 15, 2026, 10:49 PM

Medicine & Health

A Japanese doctor involved in a clinical trial of pig kidney transplants into patients, currently being conducted at American hospitals, gave an update on the progress in Tokyo on the 15th, reporting that the transplanted kidney had functioned for over 270 days in the longest-lasting patient.

This was announced on the 15th at a symposium held in Chiyoda Ward of Tokyo by Dr. Tatsuro Kawai (河合達郎) from the Massachusetts General Hospital in the United States.

At the symposium, Dr. Kawai reported that he had performed pig kidney transplants on four patients with severe kidney failure, and that the transplanted kidney functioned for 271 days in this longest-lasting patient without the need for dialysis.

This patient subsequently found a kidney donor, received a transplant and recovered.

Of the other three patients, while one died of a different illness, for the remaining two, the transplanted pig kidney was still functioning, so Dr. Kawai and his colleagues planned to continue performing surgeries and seek approval in the United States.

Regarding xenotransplantation, the transplantation of animal organs for medical treatment, a shortage of donors had led to movements in Japan to prepare clinical trials for pig kidney transplants.

At the symposium, Director Ayako Kamisato (神里彩子) of the National Center for Child Health and Development and her colleagues reported the results of a survey of over 3,200 people in Japan regarding their understanding of xenotransplantation which found out that 52.9% of respondents were unaware of xenotransplantation, and 77% would be hesitant if it were offered to them.

Dr. Kawai said, "There is an overwhelming shortage of donors in Japan, and many people give up transplanting. I would like the results of our clinical trial to be used as a reference in discussing doing transplantation in Japan."

So, a Japanese doctor involved in a clinical trial of transplanting pig kidney into patients in the US gives an update on the progress and reports that in the longest-lasting patient, the transplanted kidney has functioned for over 270 days. I think this is an impressive medical record.