Strengthen stem cell research ethics now

Protect safety of clinical trial participants

The possibility of using embryonic stem cells to treat disease, a strategy known as regenerative medicine, is not yet being explored in clinical trials, but current ethical practices need to be strengthened — now — in preparation for this possibility, according to an advisory committee at the University of California at San Francisco (UCSF).

UCSF’s Campus Advisory Committee on Human Gamete, Embryo, and Stem Cell Research reports that current practices must be amended to promote both the safety and well-being of the patients who would participate in clinical trials and the confidentiality of people who donate the embryos, oocytes, and sperm that contribute to the development of embryonic stem cells.

The recommendations of the team, which includes leading stem cell scientists, are aimed at ensuring the safety of biological materials being donated for the development of human embryonic stem cell lines, protecting the privacy of the people who donate biomaterials, and promoting effective communication between clinician–researchers and patients about the nature of early stage, or Phase I, clinical trials.

Addressing these issues would require:

  • seeking consent from donors of biological materials to allow scientists to recontact them over the years to update their medical records and rescreen them;
  • implementing stringent measures to secure donors’ confidentiality;
  • fully informed consent.

Donated biological materials hold the key to enabling scientists to develop human embryonic stem cell (hESC) lines. However, transplanted hESCs and the proteins they produce could carry infectious diseases, such as Creutzfeldt–Jakob disease, and genetic-based diseases such as cancer or Parkinson’s.

The FDA issued regulations in May 2005 for screening and testing for communicable diseases at the time of donation and for tracking transplanted materials back to the original donors. However, the UCSF team says that these regulations are insufficient.

It is critical, they say, that the consent process include asking donors to agree to be recontacted in the months or years following their donations, to provide updates on their medical history and participate, if necessary, in further screenings.

Reestablishing contact is necessary, the team says, for determining if diseases that could have been latent at the time of donation subsequently emerged. The process would allow scientists to determine if a donor has developed a disease with a strong genetic component that could affect the safety of transplanted cells. Notably, one embryonic stem cell line could be used to treat hundreds or thousands of patients. Thus, one cell line containing a pathogen or disease-causing genetic mutation could affect many patients.

Without permission to recontact and possibly rescreen donors, the team writes, scientists would be invading donors’ privacy by recontacting them. In such circumstances, the donors might refuse to share updated medical information, which would disqualify the cells for transplantation.

It is equally critical, the UCSF team writes, that stringent measures be implemented to ensure that donors’ medical records are secured. The authors advocate steps ranging from having computer files locked in a secure room and password-protected, with access limited; to having files with identifiers copy-protected and double-encrypted with one of the keys held by a high-ranking institutional official who is not involved in stem cell research; to having the records protected from subpoena by obtaining a federal Certificate of Confidentiality.

Finally, researchers should ensure that subjects are fully counseled and able to give a truly informed consent. Informed consent would include informing subjects that their therapy would involve the use of cells obtained from embryos and making clear that Phase I clinical trials are intended to begin the process of determining the safety of a given therapy and the appropriate dosage; such trials rarely lead to improvement in the patient’s condition.