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From: Celso Galli Coimbra
Sent: Tuesday, May 15, 2001 5:25 AM
Subject: [Direito_Saude] Xenotransplantation Gains Momentum
Abstract From a U.K. report questioning the technology's potential, to a controversial proposal in the United States, xenotransplantation has been receiving much policy attention in 2001. Xenotransplantation, the process of transplanting organs or cells from another species, such as pigs, into humans, has been touted over the past few years as a viable solution to the increasing shortage of human donor organs. Scientists have also been researching its potential to treat a variety of diseases such as cystic fibrosis, neurological disorders, and diabetes. Before it can be implemented successfully, xenotransplantation must surmount some safety barriers and address some risks. The major barrier to the technology is rejection by the human immune response, and scientists are experimenting with genetic modification of animal cells to make them more acceptable to the human immune system. Another concern is the risk of transmitting animal viruses into the human population. With historical incidences such as AIDS and bovine spongiform encephalopathy illustrating cross-species infection, implementation of the technology requires cautious and forward-thinking judgment. In fact, in January 1999, the Parliamentary Assembly of the Council of Europe called for a worldwide moratorium on xenotransplantation until the technology could be evaluated and guidelines established. United Kingdom In March 2001, the United Kingdom Xenotransplantation Interim Regulatory Authority (UKXIRA) released its latest annual report. The three-year-old oversight entity for cross-species transplantation concluded that risks cannot be eliminated based on current evidence and that the "uncertainty about the safety of xenotransplantation continues to be a significant obstacle." Furthermore, in a statement that struck a blow to the hopes of those waiting for a transplant, it stated that the technology is unlikely to solve problems of shortages of organs for transplantation in the near future. Cloning and genetic modification techniques to address the rejection barrier are still in their early stages. The report also impacted U.K. companies that have funneled millions into breeding genetically modified pigs. Canada The Canadian Public Health Association, however, has a different take on the technology. Its discussion paper, commissioned by Health Canada and issued the same month as the U.K. report, recognizes that a major new epidemic is the worst-case scenario posed by xenotransplantation and acknowledges the lack of scientific evidence to predict or understand the risks. However, it concluded that the technology should not be banned and that new laws may be required to deal with the risk. Heather Ross, cochair of the advisory committee for the consultation, was reported as stating, "Xenotransplantation could become a reality faster than most people think." The health department has already drafted guidelines to regulate xenotransplantation if the decision is made to procedure. Guideline on Infectious Disease Issues on Xenotransplantation Policy activity on the xenotransplantation issue has been stirring in the United States as well. On January 19, the Public Health Service (PHS) finally published the PHS Guideline on Infectious Disease Issues on Xenotransplantation. The guideline reflects comments received on the September 1996 draft, as well as scientific and international policy developments on the technology. It contains few substantive changes from the revised guideline released in May 2000. Among the many issues addressed are: source of animal care and screening and selection of animals; informed consent and patient education; health monitoring; infection control practices; and maintenance of records and samples. The final regulation also modifies the definition of xenotransplantation to include not only any procedure that involves the transplantation, implantation, or infusion of live cells, tissues, or organs from a nonhuman source into a human recipient, but also human body fluids, cells, tissues, or organs that have had ex vivo contact with live nonhuman animal cells, tissues, or organs. Under the guideline, the primary responsibility for designing and monitoring the conduct of xenotransplantation clinical trials now rests solely with the sponsor. Furthermore, long-term or life-long surveillance of xenotransplantation recipients should be implemented, and recipients and their close contacts should be deferred from donation of body fluids and other body parts. The guideline also describes the development and expansion of a pilot national xenotransplantation database to identify and gather routine data collection methods, system design, data reporting, and general start-up data from all clinical centers that conduct xenotransplantation trials and all animal facilities providing source animals. Since the scope of the guideline is limited to infectious disease issues, topics of the scientific, social, medical, public health, ethical, and legal scope will be addressed by the Secretary's Advisory Committee on Xenotransplantation (SACX). The committee was created in response to strong support for such an entity following the release of the draft guideline in 1996. In a role similar to UKXIRA's, SACX is charged with reviewing proposed clinical trial protocols, recommending policy and procedures to the secretary of health and human services, and, as needed, suggesting changes to the guideline. The committee first met on February 20-21, 2001, in Rockville, Maryland. Proposed Rule on Xenotransplantation and Gene Therapy On January 17, the Food and Drug Administration (FDA) issued a proposed rule that would require public disclosure of clinical trials involving xenotransplantation and gene therapy. The proposed rule is part of an overhaul of U.S. human subjects regulations triggered by the death of teenager Jesse Gelsinger in a 1999 gene therapy trial. Designed to address safety concerns and shortcomings in the existing federal regulatory framework, the proposal requires public access to information from the investigational new drug application (IND) in the xenotransplantation and gene therapy fields. The information includes clinical trial protocols, enrollment criteria, product and patient safety data, results from preclinical and clinical studies, and the regulatory status of the investigation. As the studies progress, sponsors would submit redacted versions of subsequent annual reports and adverse event filings. The public would access the information through the FDA Web site. Officials believe that the information would enable patients, families, health care workers, and ethicists to better assess the risks involved in such studies and the need for additional control. Former FDA commissioner Jane Henney called the agency's action an "important step in ensuring greater public confidence in these revolutionary therapeutic technologies." Although the technologies hold great promise, they also pose a "remote, but unique risk" to study participants. "Our proposal will ensure that the public is fully informed as we investigate these new public health opportunities and challenges." Henney resigned as FDA commissioner on January 2, when the administration changed. The controversial proposal is seen by many as a radical departure from 30 years of FDA policy. No information about the IND or other filings were available to the public before the products gained final market approval. However, the agency believes that the proposed regulation will update its public access requirements and bring them in line with those of other government agencies that oversee similar types of research. The proposal drew strong opposition from industry. Biotech companies are also concerned that the proposal could reduce traditional protections for trade information. The release of toxicity data on production methods could compromise confidentiality and create difficulties for developing products. The Biotechnology Industry Organization (BIO), located in Washington, D.C., has objected to releasing information on adverse events involving patients before causes are determined. Carl Feldbaum, president of BIO, argues that "[the] vast majority of adverse events in clinical trials are related to the patient's underlying diseases." Furthermore, preliminary safety data and adverse event reports can be taken out of context, be misinterpreted, and cause unnecessary alarm in the public mind. Industry is also concerned that the proposed regulation's broad wording may extend disclosure requirements beyond studies involving gene therapy and xenotransplantation. Already the agency asks in its proposal whether the scope of the new policy should be extended to products such as vaccines and whether disclosure also should cover study information filed in biologics licensing applications. The comment period for the proposal ended on April 18. As the proposal was one of Henney's last actions as FDA commissioner, the Bush adminsitration is expected to review the disclosure policy closely. Sanyin Siang works on a variety of issues at the intersection of science, ethics, and law at the Directorate for Science Policy Programs of the American Association for the Advancement of Science.
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