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.

NIH: Recombinant DNA Advisory Committee Review No Longer Necessary for Gene Therapy Trials

In a move that signals the maturity of the gene therapy field, the National Institutes of Health (NIH) has announced that it will no longer subject all applications for gene therapy trials to automatic review by the Recombinant DNA Advisory Committee (RAC). Gene therapy is defined as: 

the transfer of genetic material into humans with the goal of replacing or compensating for the function of abnormal genes, or to enhance the immune system’s ability to attack cancer cells.

RAC occupies a singular place in the history of government oversight of new technologies. The committee was established in 1974, following increasing concern by scientists in the then-emerging field of molecular biology as the techniques involving recombinant DNA were developed and disseminated. The Asilomar conference of 1975 originated with scientIsts, and led to the publication of physical and biological containment strategies to limit the risk of working with recombinant organisms (e.g., bacteria, viruses). RAC issued the first Recombinant DNA Research Guidelines in 1976, and these were the precursor to later guidelines for the gene therapy applications that were first submitted to RAC in the late 1980's. Now, following a study from the Institute of Medicine that called for streamlining the review process for gene therapy (removing redundancies in the review process), the NIH has acceded to their recommendation that RAC reviews of gene therapy be reserved for exceptional cases where both of these conditions exist: 

1. The protocol review could not be adequately performed by other regulatory and oversight processes (for example, the institutional review boards, institutional biosafety committees, and the FDA).

2. One or more of the following criteria are satisfied: 

Protocol uses a new vector, genetic material, or delivery method that represents a first-in-human experience, thus representing unknown risk.

Protocol relies on preclinical safety data that were obtained using a new preclinical model system of unknown and unconfirmed value.

Proposed vector, gene construct, or method of delivery is associated with possible toxicities that are not widely known and that may render it difficult for local and federal regulatory bodies to evaluate the protocol rigorously.

In reviewing the history of RAC oversight for the gene therapy field, the IOM stated: 

When recombinant DNA technology was new, and the many risks concerning individual clinical trial protocols were uncertain, the public, scientists, and policy makers raised important questions about potential dangers—such as whether this technology could harm patients, create new infectious organisms, or make genetic alterations that could be passed down to future human generations. In its report, the IOM committee finds that the major concerns about recombinant DNA from 40 years ago do not raise the same level of concern today, as hundreds of gene therapy clinical trials have evaluated the technique’s safety and effectiveness. 

The RAC committee stands as a model of a technology-specific review body set up to augment existing regulatory processes in the case where a novel technology has emerged with potential risks to health and safety. This recent move now becomes a model for partial deregulation of a maturing technology. Gene therapy protocols will continue to be reviewed by the FDA and institutional oversight panels. The IOM report recognizes that this model of regulatory layering still has relevance for current emerging technologies, and specifically cites the field of nanotechnology as a candidate for a future RAC-like review body to consider its specific applications in medicine.

Cancer Progress in Embattled Gene Therapy Field

The field of gene therapy - the premise of providing therapeutic benefit by introducing genes into a patient - has been beleagured by a lack of promising clinical results, coupled with a history of erratic clinical attempts, with the most prominent example being that of patient Jesse Gelsinger, who was improperly managed as a patient in a gene therapy trial, leading to his death.  A lack of truly informed consent regarding conflicts of interest held by the researchers running the trial meant that the Gelsinger family was underinformed about the risks and biases that attended to the clinical trial. This episode of mismanagement of the patient- researcher relationship has served as a cautionary tale for other biotechnology therapies which are studied by those with a financial stake in a (positive) outcome. Beyond this individual case, gene therapy trials are still subject to the regulatory review of the NIH Recombinant DNA Advisory Committee (RAC). Against this backdrop, the recent report of a significant remission achieved using genetically altered T cells from leukemia patients illustrates again the promise of gene therapy, coupled with the theoretical assumption that the patient's immune system can be harnessed to fight cancer cells. Article in New England Journal of Medicine.