Estimating Demand for Germline Genome Editing: An In Vitro Fertilization Clinic Perspective

Embryo and fetal gene editing: Technical challenges and progress toward clinical applications

Gene modification therapies (GMTs) are slowly but steadily making progress toward clinical application. As the majority of rare diseases have an identified genetic cause, and as rare diseases collectively affect 5% of the global population, it is increasingly important to devise gene correction strategies to address the root causes of the most devastating of these diseases and to provide access to these novel therapies to the most affected populations. The main barriers to providing greater access to GMTs continue to be the prohibitive cost of developing these novel drugs at clinically relevant doses, subtherapeutic effects, and toxicity related to the specific agents or high doses required. In vivo strategy and treating younger patients at an earlier course of their disease could lower these barriers. Although currently regarded as niche specialties, prenatal and preconception GMTs offer a robust solution to some of these barriers. Indeed, treating either the fetus or embryo benefits from economy of scale, targeting pre-pathological tissues in the fetus prior to full pathogenesis, or increasing the likelihood of complete tissue targeting by correcting pluripotent embryonic cells. Here, we review advances in embryo and fetal GMTs and discuss requirements for clinical application.

Germline Gene Editing: The Gender Issues

Human germline gene editing constitutes an extremely promising technology; at the same time, however, it raises remarkable ethical, legal, and social issues. Although many of these issues have been largely explored by the academic literature, there are gender issues embedded in the process that have not received the attention they deserve. This paper examines ways in which this new tool necessarily affects males and females differently-both in rewards and perils. The authors conclude that there is an urgent need to include these gender issues in the current debate, before giving a green light to this new technology.

Reproductive Embryo Editing: Attending to Justice

The use of embryonic genome editing tools is often touted as a way to ensure the birth of healthy and genetically related children. Many would agree that this is a worthy goal. Yet the purpose of this article is to argue that, if we are concerned with justice, accepting such a goal as morally appropriate commits one to rejecting the use of social resources for further development of embryo editing for reproductive purposes. This is so because there are safer and more effective means that can allow many more prospective parents to achieve the same valued goal and that can offer additional benefits.

Ethical considerations of preconception and prenatal gene modification in the embryo and fetus

The National Academies of Sciences and Medicine 2020 consensus statement advocates the reinstatement of research in preconception heritable human genome editing (HHGE), despite the ethical concerns that have been voiced about interventions in the germline, and outlines criteria for its eventual clinical application to address monogenic disorders. However, the statement does not give adequate consideration to alternative technologies. Importantly, it omits comparison to fetal gene therapy (FGT), which involves gene modification applied prenatally to the developing fetus and which is better researched and less ethically contentious. While both technologies are applicable to the same monogenic diseases causing significant prenatal or early childhood morbidity, the benefits and risks of HHGE are distinct from FGT though there are important overlaps. FGT has the current advantage of a wealth of robust preclinical data, while HHGE is nascent technology and its feasibility for specific diseases still requires scientific proof. The ethical concerns surrounding each are unique and deserving of further discussion, as there are compelling arguments supporting research and eventual clinical translation of both technologies. In this Opinion, we consider HHGE and FGT through technical and ethical lenses, applying common ethical principles to provide a sense of their feasibility and acceptability. Currently, FGT is in a more advanced position for clinical translation and may be less ethically contentious than HHGE, so it deserves to be considered as an alternative therapy in further discussions on HHGE implementation.

Toward Anticipatory Governance of Human Genome Editing: A Critical Review of Scholarly Governance Discourse

The rapid development of human genome editing (HGE) techniques evokes an urgent need for forward-looking deliberation regarding the aims, processes, and governance of research. The framework of anticipatory governance (AG) may serve this need. This article reviews scholarly discourse about HGE through an AG lens, aiming to identify gaps in discussion and practice and suggest how AG efforts may fill them. Discourse on HGE has insufficiently reckoned with the institutional and systemic contexts, inputs, and implications of HGE work, to the detriment of its ability to prepare for a variety of possible futures and pursue socially desirable ones. More broadly framed and inclusive efforts in foresight and public engagement, focused not only upon the in-principle permissibility of HGE activities but upon the contexts of such work, may permit improved identification of public values relevant to HGE and of actions by which researchers, funders, policymakers, and publics may promote them.

Heritable human genome editing: Research progress, ethical considerations, and hurdles to clinical practice

Our genome at conception determines much of our health as an adult. Most human diseases have a heritable component and thus may be preventable through heritable genome editing. Preventing disease from the beginning of life before irreversible damage has occurred is an admirable goal, but the path to fruition remains unclear. Here, we review the significant scientific contributions to the field of human heritable genome editing, the unique ethical challenges that cannot be overlooked, and the hurdles that must be overcome prior to translating these technologies into clinical practice.

Should germline genome editing be allowed? The effect of treatment characteristics on public acceptability

STUDY QUESTION

To what extent do characteristics of germline genome editing (GGE) determine whether the general public supports permitting the clinical use of GGE?

SUMMARY ANSWER

The risk that GGE would cause congenital abnormalities had the largest effect on support for allowing GGE, followed by effectiveness of GGE, while costs, the type of application (disease or enhancement) and the effect on child well-being had moderate effects.

WHAT IS KNOWN ALREADY

Scientific progress on GGE has increased the urgency of resolving whether and when clinical application of GGE may be ethically acceptable. Various expert bodies have suggested that the treatment characteristics will be key in determining whether GGE is acceptable. For example, GGE with substantial risks (e.g. 15% chance of a major congenital abnormality) may be acceptable to prevent a severe disease but not to enhance non-medical characteristics or traits of an otherwise healthy embryo (e.g. eye colour or perhaps in the future more complex traits, such as intelligence). While experts have called for public engagement, it is unclear whether and how much the public acceptability of GGE is affected by the treatment characteristics proposed by experts.

STUDY DESIGN, SIZE, DURATION

The vignette-based survey was disseminated in 2018 among 1857 members of the Dutch general public. An online research panel was used to recruit a sample representing the adult Dutch general public.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A literature review identified the key treatment characteristics of GGE: the effect on the well-being of the future child, use for disease or enhancement, risks for the future child, effectiveness (here defined as the chance of a live birth, assuming that if the GGE was not successful, the embryo would not be transferred), cost and availability of alternative treatments/procedures to prevent the genetic disease or provide enhancement (i.e. preimplantation genetic testing (PGT)), respectively. For each treatment characteristic, 2-3 levels were defined to realistically represent GGE and its current alternatives, donor gametes and ICSI with PGT. Twelve vignettes were created by fractional factorial design. A multinominal logit model assessed how much each treatment characteristic affected participants' choices.

MAIN RESULTS AND THE ROLE OF CHANCE

The 1136 respondents (response rate 61%) were representative of the Dutch adult population in several demographics. Respondents were between 18 and 89 years of age. When no alternative treatment/procedure is available, the risk that GGE would cause (other) congenital abnormalities had the largest effect on whether the Dutch public supported allowing GGE (coefficient = -3.07), followed by effectiveness (coefficient = 2.03). Costs (covered by national insurance, coefficient = -1.14), the type of application (disease or enhancement; coefficient = -1.07), and the effect on child well-being (coefficient = 0.97) had similar effects on whether GGE should be allowed. If an alternative treatment/procedure (e.g. PGT) was available, participants were not categorically opposed to GGE, however, they were strongly opposed to using GGE for enhancement (coefficient = -3.37). The general acceptability of GGE was higher than participants' willingness to personally use it (P < 0.001). When participants considered whether they would personally use GGE, the type of application (disease or enhancement) was more important, whereas effectiveness and costs (covered by national insurance) were less important than when they considered whether GGE should be allowed. Participants who were male, younger and had lower incomes were more likely to allow GGE when no alternative treatment/procedure is available.

LIMITATIONS, REASONS FOR CAUTION

Some (e.g. ethnic, religious) minorities were not well represented. To limit complexity, not all characteristics of GGE could be included (e.g. out-of-pocket costs), therefore, the views gathered from the vignettes reflect only the choices presented to the respondents. The non-included characteristics could be connected to and alter the importance of the studied characteristics. This would affect how closely the reported coefficients reflect 'real-life' importance.

WIDER IMPLICATIONS OF THE FINDINGS

This study is the first to quantify the substantial impact of GGE's effectiveness, costs (covered by national insurance), and effect on child well-being on whether the public considered GGE acceptable. In general, the participants were strikingly risk-averse, in that they weighed the risks of GGE more heavily than its benefits. Furthermore, although only a single study in one country, the results suggests that-if sufficiently safe and effective-the public may approve of using GGE (presumably combined with PGT) instead of solely PGT to prevent passing on a disease. The reported public views can serve as input for future consideration of the ethics and governance of GGE.

STUDY FUNDING/COMPETING INTEREST(S)

Young Academy of the Royal Dutch Academy of Sciences (UPS/RB/745), Alliance Grant of the Amsterdam Reproduction and Development Research Institute (2017-170116) and National Institutes of Health Intramural Research Programme. No competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Responsible Translational Pathways for Germline Gene Editing?

PURPOSE OF REVIEW

Continued development of gene editing techniques has raised the real possibility of clinical application of germline gene editing. These results, as well as reports of an unethical experiment which resulted in the birth of at least two children from edited embryos in 2018, have highlighted the urgency and importance of ethical issues about translational pathways for editing of human germline cells. Charting responsible translational pathways for germline gene editing requires tackling some significant and complex ethical issues.

RECENT FINDINGS

A literature on development of clinical applications of germline gene editing is emerging, and several key ethical issues are coming into focus as major challenges for responsible translational pathways.

SUMMARY

Potential clinical utility, clinical justification, and human subjects research for germline gene editing raise outstanding ethical questions. Work on these questions will help provide guidance to researchers and clinicians and direct translational projects toward justifiable applications.

Ethical issues related to research on genome editing in human embryos

Although the potential advantages of clinical germline genome editing (GGE) over currently available methods are limited, the implementation of GGE in the clinic has been proposed and discussed. Ethical issues related to such an application have been extensively debated, meanwhile, seemingly less attention has been paid to ethical implications of studies which would have to be conducted in order to evaluate potential clinical uses of GGE. In this article, we first provide an overview of the debate on potential clinical uses of GGE. Then, we discuss questions and ethical issues related to the studies relevant to evaluation of potential clinical uses of GGE. In particular, we describe the problems related to the acceptable safety threshold, current technical hurdles in human GGE, the destruction of human embryos used in the experiments, involvement of egg donors, and genomic sequencing performed on the samples of the research participants. The technical and ethical problems related to studies on GGE should be acknowledged and carefully considered in the process of deciding to apply technology in such a way that will provide benefits and minimize harms.

Germline Genome Editing Research: What Are Gamete Donors (Not) Informed About in Consent Forms?

The potential for using germline genome editing (GGE) in humans has garnered a lot of attention, both for its scientific possibilities as well as for the ethical, legal, and social challenges it ignites. The ethical debate has focused primarily on the suggestions of using GGE to establish a pregnancy (i.e., to offer it in a clinical setting), which is, to date, illegal in many jurisdictions. The use of GGE in research (where a pregnancy would not be established) has received much less attention, despite the fact that it raises serious ethical and social issues as well. Herein, we report on the analysis of informed consent forms for egg and sperm donation used in a widely publicized study where genome editing was used to correct a disease-causing genetic mutation in human embryos. Importantly, embryos were created using eggs and sperm obtained specifically for these experiments. The analysis indicates deficiencies in how the forms addressed various issues, including limited and potentially misleading information about the sensitive nature of the study, the lack of an explicit mention of genomic sequencing, as well as the poor readability of the forms. Furthermore, the arguably high compensation of U.S.$5,000 for egg donors raises questions about undue inducement to participate in research. Moreover, since the procurement of eggs involves serious health risks, it may be questioned whether research requiring such a procedure should be pursued. If such experiments are continued, donors should be informed about all relevant aspects in order to make informed decisions about participating.