Islet Xenotransplantation: Are We Really Ready for Clinical Trials?

Abstract

Four clinical trials of porcine islet transplantation have been reported, and there are verbal reports that clinical trials on much larger scales are continuing in centers in China and Russia. The four reported trials are briefly reviewed and, in the light of the present status of experimental islet xenotransplantation, consideration is given to whether such trials are currently justified. The Ethics Committee of the International Xenotransplantation Association has (1) emphasized the need for encouraging studies in non-human primates before clinical trials should be undertaken, (2) mandatory monitoring for the transfer of porcine microorganisms, and (3) careful regulation and oversight by recognized bodies. Other aspects of the topic, such as the need for informed consent, are briefly discussed. We conclude that, at the present time, more data documenting convincing efficacy, focused on clinically applicable immunosuppressive regimens, are needed to justify the initiation of closely monitored clinical trials. A clinical trial may then be justified even though the potential risk to the patients, and possibly for society, will not be zero.

Ethical considerations in tissue engineering research: Case studies in translation

“…Another such population is patients who have reduced awareness of hypoglycemia. This is a dangerous condition [54]; consequently, these individuals may be candidates for early clinical trials involving either islet transplantation or the BAP, since current insulin therapies are inadequate for them. For populations like these, early-stage research involving patient-subjects with diabetes most resembles Phase I oncology research, where patients are chosen as subjects because there are no adequate standard treatments currently available to them.…”

Current status and future of clinical islet xenotransplantation

“…However, that clinical trial was criticized because it was performed on adolescent patients and there is no solid regulatory framework for xenotransplantation in Mexico …”

Xenotransplantation Literature Update May–June 2006

“…During the period, May–June, 2006, five reviews on xenotransplantation were published [1–5]. Cozzi et al [1] discussed the current status and future perspectives of xenotransplantation, and concluded that progression to the clinic should not be viewed as an option until a favorable risk/benefit ratio was achieved.…”

“…Rood and Cooper [2] reviewed all clinical trials of islet xenotransplantation reported to date, i.e., four trials of porcine‐to‐human islet xenotransplantation. The authors also discussed the recommendations of the Ethical Committee of the International Xenotransplantation Association (IXA) and the importance of informed consent in clinical xenotransplantation studies.…”