June 22, 2016

RAC Approves First Use of CRISPR Gene-Editing Protocol in Humans

Yesterday, the Recombinant DNA Advisory Committee (RAC), a federal advisory committee to the NIH, held a public meeting to consider the first submission for approval to use a CRISPR/Cas9-based (CRISPR) study protocol with human patients. CRISPR is a technique that allows genes to be edited; it has swept through biomedical science in the last few years as a breakthrough technology. The RAC committee has provided oversight for the field of gene transfer therapies for decades (and supplements FDA and local institutional oversight by IRBs and IBCs). As an advisory committee to NIH, first constituted in 1974, RAC's regulatory portfolio for human experiments began with reviewing gene transfer studies pursuant to the NIH Guidelines for Research Involving Recombinant or Synthetic Nucleic Acid Molecules. The field of "gene therapy" has largely been comprised of studies involving gene transfer into patients to correct, replace, or diminish gene activity relevant to various clinical conditions; to date, several thousand gene therapy clinical trials worldwide have been conducted. RAC's jurisdiction extends to the use of gene-editing protocols, as well as other gene-altering technologies such as RNA interference. Now, a collaborative effort from the University of Pennsylvania (Penn), M.D. Anderson Cancer Center, and the University of California, San Francisco produced a proposed study protocol involving CRISPR gene-editing that was discussed and evaluated by the RAC this week at its meeting. The protocol involves an ex vivo technology where T cells of cancer patients will be removed and subject to gene-editing to alter several cell receptors before the cells are infused back into the patient. The goal is to engineer the T cells of the immune system so that they target and destroy cancer cells; this initial study is to identify any safety issues that might emerge. The recruited patients have either myeloma, melanoma, or sarcomas and would be those for which conventional therapies are not available or effective. During the meeting, questions were raised about potential conflicts of interest due to financial interests of some investigators, as well as the involvement of Penn, as it was the site of the now well-known 1999 gene therapy trial that resulted in the death of Jesse Gelsinger; that trial had notable flaws involving the transparency of preclinical testing and of competing financial interests. After public review and discussion of the protocol, the committee voted to approve the protocol. Yesterday's approval marks the first RAC-sanctioned use of CRISPR technology in human patients.

This is the first study protocol submitted to RAC that uses CRISPR in humans, but it is not the first gene-editing human protocol that RAC has considered. Sangamo BioSciences received approval to use its zinc-finger gene-editing technology (ZFN) in two different human trials: an ex vivo protocol approved in 2007, and an in vivo protocol approved in 2015. In what appeared to be a coincidence, yesterday's meeting also considered the first proposed gene therapy trial to treat Ornithine Transcarbamylase (OTC) Deficiency since the 1999 Gelsinger trial. Several discussants referenced the Gelsinger incident in their comments. The committee held a discussion of whether preclinical trials for the gene transfer method in non-human primates were necessary before approval (only mice studies were provided); RAC then voted an approval with stipulated conditions

As gene transfer studies have become more routine over the last several decades, the scope and need for continued RAC oversight has been questioned. A recent study of RAC that was conducted by the Institute of Medicine examined whether gene transfer oversight by RAC continued to be necessary; the report concluded that only new protocols presenting novel vectors or technical approaches needed to be evaluated by RAC. However, the IOM committee explored whether the RAC model of a public advisory committee could be utilized more generically for other emerging biotechnologies. including, for example, protocols from the field of nanobiotechnology or synthetic biology, for example. The IOM report endorsed consideration of an expanded scope for RAC or an advisory committee with similar attributes to provide the kind of oversight for new technologies as RAC has provided for decades in the field of gene therapy.

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