April 30, 2015

Germline Genetic Engineering of Embryos Reported; Policy Debates Intensify on Prohibitions

Following on the recent post, the rush to develop some initial policy statements on the use of genome editing techniques for germline engineering is now understood following the first publication of an attempt to perform germline engineering on embryos using the CRISPR/Cas 9 (CRISPR) system, as reported by Chinese scientists. Several weeks ago, two separate policy statements were issued by experts in genome editing who called for either a moratorium or an ethics-initiated slowdown on any use of the technique on embryos. At the time, there were rumors of an imminent publication, and this was true. The new publication reports that the use of CRISPR to alter the germline of about 86 non-viable embryos had mixed results; some of the embryos accepted the genetic changes, but some did not and “off-target” events were reported, indicating that unintended genomic alterations occurred. These experiments have been widely reported, and have alerted the general public to an issue that they were generally unaware of. Public reaction has followed as well as some official commentary. The journal that published the paper has now issued a statement on its decision to publish: 
Protein & Cell has fully realized that this study can provide direct evidences to address some of safety concerns of the CRISPR/Cas9 technique. It may also raise a series of questions and bring further controversies to the field of gene-editing research. In this unusual situation, the editorial decision to publish this study should not be viewed as an endorsement of this practice nor an encouragement of similar attempts, but rather the sounding of an alarm to draw immediate attention to the urgent need to rein in applications of gene-editing technologies, especially in the human germ cells or embryos.
Official responses have also followed the publication of the CRISPR embryo studies. The NIH has issued a policy declaration making it clear that no federal funding is available for research that uses genome modification to the germline of a fertilized egg or embryo. The statement anchors the policy in the already existing legal/regulatory climate: 
However, NIH will not fund any use of gene-editing technologies in human embryos. The concept of altering the human germline in embryos for clinical purposes has been debated over many years from many different perspectives, and has been viewed almost universally as a line that should not be crossed. Advances in technology have given us an elegant new way of carrying out genome editing, but the strong arguments against engaging in this activity remain. These include the serious and unquantifiable safety issues, ethical issues presented by altering the germline in a way that affects the next generation without their consent, and a current lack of compelling medical applications justifying the use of CRISPR/Cas9 in embryos.
Practically, there are multiple existing legislative and regulatory prohibitions against this kind of work. The Dickey-Wicker amendment prohibits the use of appropriated funds for the creation of human embryos for research purposes or for research in which human embryos are destroyed (H.R. 2880, Sec. 128). Furthermore, the NIH Guidelines state that the Recombinant DNA Advisory Committee “will not at present entertain proposals for germ line alteration.” It is also important to note the role of the U.S. Food and Drug Administration (FDA) in this arena, which applies not only to federally funded research, but to any research in the U.S. The Public Health Service Act and the Federal Food, Drug, and Cosmetic Act give the FDA the authority to regulate cell and gene therapy products as biological products and/or drugs, which would include oversight of human germline modification. During development, biological products may be used in humans only if an investigational new drug application is in effect (21 CFR Part 312). 
The NIH reiterates the lack of federal funding for any CRISPR (or other technology) attempts at germline engineering. It notes that the combination of existing prohibitions on funding embryo research combined with the ongoing supervision of gene therapy by RAC, supplemented with FDA pronouncements on its jurisdiction over some biotechnology products, create a patchwork of constraints on research in the U.S. RAC considered fetal gene therapy in 1999; as the NIH statement summarizes, the committee was not receptive to this form of prenatal genetic intervention. This new debate, however, focuses on a much more radical genetic intervention. The Chinese experiments were generally not "successful" in the goal of altering the specific gene in the target embryos; this lack of success, while derived from controversial experiments, will only bolster the case for halting any such scientific work, as the recent work validates the safety concerns alone. But what is emerging - despite any enforceable international restrictions - is an urgency to codify resistance into regulation sooner rather than later.

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