Japan has demonstrated its interest in animal-to-human transplants by hosting its first international meeting to discuss the technique. But as expected from a country that is only just coming to terms with the process of human organ transplantation, the 5th Meeting of the International Xenotransplantation Association in Nagoya revealed the lack of a regulatory framework for potential xenotransplantation trials.
According to Kikuo Nomoto, a professor in the Department of Immunology at the University of Kyushu, the Japanese Ministry of Health and Welfare (MHW) has established a blueprint for a regulatory framework for xenotransplantation studies that is compatible with the regulatory approaches proposed in Europe and the US. This would include the creation of a surveillance agency to monitor transplant recipients and their closest contacts for the transmission of xenotic viruses. But such regulation looks unlikely to be implemented in the near future, and in the meantime clinical trials with xenotransplants are likely take place in a "dangerous regulatory void," says Jiro Nudeshima, a health policy analyst at the Mitsubishi Kasei Institute of Life Sciences.
Nudeshima points out that according to Japanese legislation, trials that are not related to new pharmaceutical products are not subject to oversight by the Health Ministry. "At present, there are no real guidelines for clinical trials with xenotransplantation, neither has the Ministry any real mechanism to monitor such trials," he says.
Researchers who are pushing ahead with the technique are encountering this vacuum. Takashi Omoto, a neurosurgeon at Okayama University, has prepared a protocol for clinical trials of xenografts of rat-derived islet cells to treat Parkinson disease. Omoto consulted with both the Education Ministry and the MHW on the issue, and was advised to submit his protocol to the university's Ethics Committee, which approved it this March. "Neither the Education Ministry nor the MHW seemed to be prepared to take any responsibility for this," says Omoto.
Only a handful of human organ transplants have been performed in Japan since a new law regulating organ donation went into force just over a year ago, and almost ten years after a MHW expert panel on brain death ("Noshi rincho") delivered its report on the issue. Hiroshi Takagi, director of the JR Tokai General Hospital in Nagoya, and head of the local organization committee for the xenotransplantation meeting, argues that "it may take another decade before the practice of organ transplants becomes accepted" and that "Japan should pursue research on alternatives like xenografts more aggressively."
But Nomoto, a prime mover behind the new human transplant law, argues that is simply too early to push ahead with xenotransplanation. "We have to overcome the mental barriers towards organ transplants in this country before we can deal with any other issue."
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Triendl, R. Japan hosts its first xenotransplantation conference. Nat Med 5, 1335 (1999). https://doi.org/10.1038/70887