The Daunting Economics of Therapeutic Genome Editing

Genome Editing Therapy for the Blood: Ex Vivo Success and In Vivo Prospects

Hematopoietic stem cells (HSCs) provide the body with a continuous supply of healthy, functional blood cells. In patients with hematopoietic malignancies, immunodeficiencies, lysosomal storage disorders, and hemoglobinopathies, therapeutic genome editing offers hope for corrective intervention, with even modest editing efficiencies likely to provide clinical benefit. Engineered white blood cells, such as T cells, can be applied therapeutically to address monogenic disorders of the immune system, HIV infection, or cancer. The versatility of CRISPR-based tools allows countless new medical interventions for diseases of the blood, and rapid ex vivo success has been demonstrated in hemoglobinopathies via transplantation of the patient's HSCs following genome editing in a laboratory setting. Here we review recent advances in therapeutic genome editing of HSCs and T cells, focusing on the progress in ex vivo contexts, the promise of improved access via in vivo delivery, as well as the ongoing preclinical efforts that may enable the transition from ex vivo to in vivo administration. We discuss the challenges, limitations, and future prospects of this rapidly developing field, which may one day establish CRISPR as the standard of care for some diseases affecting the blood.

Affordable Pricing of CRISPR Treatments is a Pressing Ethical Imperative

Casgevy, the world's first approved CRISPR-based cell therapy, has been priced at $2.2 million per patient. Although this hefty price tag was widely anticipated, the extremely high cost of this and other cell and gene therapies poses a major ethical issue in terms of equitable access and global health. In this Perspective, we argue that lowering the prices of future CRISPR therapies is an urgent ethical imperative. Although we focus on Casgevy as a case study, much of our analysis can be extrapolated to the controversies over affordable access to other gene and cell therapies. First, we explain why this first-of-its-kind CRISPR therapy might be so expensive. We then analyze the ethical issues of equity and global health of early CRISPR treatments. Next, we discuss potential solutions to lower the prices of CRISPR gene therapies. We conclude that the approval of CRISPR transforms our obligations of justice and compels us to bring future gene therapies to the maximum possible number of patients with serious genetic diseases at affordable prices.

Targeted nonviral delivery of genome editors in vivo

Cell-type-specific in vivo delivery of genome editing molecules is the next breakthrough that will drive biological discovery and transform the field of cell and gene therapy. Here, we discuss recent advances in the delivery of CRISPR-Cas genome editors either as preassembled ribonucleoproteins or encoded in mRNA. Both strategies avoid pitfalls of viral vector-mediated delivery and offer advantages including transient editor lifetime and potentially streamlined manufacturing capability that are already proving valuable for clinical use. We review current applications and future opportunities of these emerging delivery approaches that could make genome editing more efficacious and accessible in the future.

CRISPR in Public Health: The Health Equity Implications and Role of Community in Gene-Editing Research and Applications

CRISPR (clustered regularly interspaced short palindromic repeats) is a Nobel Prize-winning technology that holds significant promise for revolutionizing the prevention and treatment of human disease through gene editing. However, CRISPR's public health implications remain relatively uncertain and underdiscussed because (1) targeting genetic factors alone will have limited influence on population health, and (2) minority populations (racial/ethnic, sexual and gender)-who bear the nation's greatest health burdens-historically suffer unequal benefits from emerging health care innovations and tools. This article introduces CRISPR and its potential public health benefits (e.g., improving virus surveillance, curing genetic diseases that pose public health problems such as sickle cell anemia) while outlining several major ethical and practical threats to health equity. This includes minorities' grave underrepresentation in genomics research, which may lead to less effective and accepted CRISPR tools and therapies for these groups, and their anticipated unequal access to these tools and therapies in health care. Informed by the principles of fairness, justice, and equitable access, ensuring gene editing promotes rather than diminishes health equity will require the meaningful centering and engagement of minority patients and populations in gene-editing research using community-based participatory research approaches. (Am J Public Health. 2023;113(8):874-882. https://doi.org/10.2105/AJPH.2023.307315).

Correcting inborn errors of immunity: From viral mediated gene addition to gene editing

Allogeneic hematopoietic stem cell transplantation is an effective treatment to cure inborn errors of immunity. Remarkable progress has been achieved thanks to the development and optimization of effective combination of advanced conditioning regimens and use of immunoablative/suppressive agents preventing rejection as well as graft versus host disease. Despite these tremendous advances, autologous hematopoietic stem/progenitor cell therapy based on ex vivo gene addition exploiting integrating γ-retro- or lenti-viral vectors, has demonstrated to be an innovative and safe therapeutic strategy providing proof of correction without the complications of the allogeneic approach. The recent advent of targeted gene editing able to precisely correct genomic variants in an intended locus of the genome, by introducing deletions, insertions, nucleotide substitutions or introducing a corrective cassette, is emerging in the clinical setting, further extending the therapeutic armamentarium and offering a cure to inherited immune defects not approachable by conventional gene addition. In this review, we will analyze the current state-of-the art of conventional gene therapy and innovative protocols of genome editing in various primary immunodeficiencies, describing preclinical models and clinical data obtained from different trials, highlighting potential advantages and limits of gene correction.

Advances in Genetic Editing of the Human Embryo

BACKGROUND

Genetic engineering has allowed a major development of research in this field, with specialists attempting to edit the human genome, after the successful editing of the genomes of plants and animals. However, human gene editing technologies are at the center of ethical debates around the world.

AREAS OF UNCERTAINTY

Ethical concerns about genetic editing of the human embryo raise several issues that can be viewed through the prism of optimism and reluctance leading to a number of recommendations regarding the acceptance of what may soon become a reality.

DATA SOURCES

A literature search was conducted through PubMed, MEDLINE, Plus, Scopus, and Web of Science (2015-2022) using combinations of keywords, including: human genome or gene editing plus ethics.

ETHICS AND THERAPEUTIC ADVANCES

Gene therapy is seen by researchers as a way to solve congenital diseases, multifactorial diseases in general or specific diseases such as cystic fibrosis, muscular dystrophy, or can increase resistance to HIV infection. Genome editing technologies, germline gene editing, clustered regularly interspaced short palindromic repeats gene editing technology, technologies such as zinc finger nucleases are not only advanced gene therapies that require solving technical problems, but also techniques that require complex and complete analysis of ethical problems. Genetic engineering raises many ethical concerns such as: safety concerns especially the risk of off-target effects; autonomy of the individual-with the limitation of the future generations to consent for an intervention over their genome; social justice-keeping in mind the costs of the procedures and their availability to the general population. Discussions can go further from questions such as "How can we do this?" to questions such as "Should we do this?" or "Is society ready to accept this technology and is it able to manage it rationally?"

CONCLUSIONS

The ethics of biomedical research should be based on global dialogue, on the involvement of experts and the public, to achieve a broad social consensus. The fundamental review of the ethics of genetics is a desire and an opportunity of the current period.

RNA in Therapeutics: CRISPR in the Clinic

The advent of the CRISPR-Cas genome editing platform has greatly enhanced the capabilities of researchers in many areas of biology. Its use has also been turned to the development of therapies for genetic diseases and to the enhancement of cell therapies. This review describes some recent advances in these areas.

Synthetic Biology Design as a Paradigm Shift toward Manufacturing Affordable Adeno-Associated Virus Gene Therapies

Gene therapy has demonstrated enormous potential for changing how we combat disease. By directly engineering the genetic composition of cells, it provides a broad range of options for improving human health. Adeno-associated viruses (AAVs) represent a leading gene therapy vector and are expected to address a wide range of conditions in the coming decade. Three AAV therapies have already been approved by the FDA to treat Leber's congenital amaurosis, spinal muscular atrophy, and hemophilia B. Yet these therapies cost around $850,000, $2,100,000, and $3,500,000, respectively. Such prices limit the broad applicability of AAV gene therapy and make it inaccessible to most patients. Much of this problem arises from the high manufacturing costs of AAVs. At the same time, the field of synthetic biology has grown rapidly and has displayed a special aptitude for addressing biomanufacturing problems. Here, we discuss emerging efforts to apply synthetic biology design to decrease the price of AAV production, and we propose that such efforts could play a major role in making gene therapy much more widely accessible.

Current landscape of gene-editing technology in biomedicine: Applications, advantages, challenges, and perspectives

The expanding genome editing toolbox has revolutionized life science research ranging from the bench to the bedside. These "molecular scissors" have offered us unprecedented abilities to manipulate nucleic acid sequences precisely in living cells from diverse species. Continued advances in genome editing exponentially broaden our knowledge of human genetics, epigenetics, molecular biology, and pathology. Currently, gene editing-mediated therapies have led to impressive responses in patients with hematological diseases, including sickle cell disease and thalassemia. With the discovery of more efficient, precise and sophisticated gene-editing tools, more therapeutic gene-editing approaches will enter the clinic to treat various diseases, such as acquired immunodeficiency sydrome (AIDS), hematologic malignancies, and even severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. These initial successes have spurred the further innovation and development of gene-editing technology. In this review, we will introduce the architecture and mechanism of the current gene-editing tools, including clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated nuclease-based tools and other protein-based DNA targeting systems, and we summarize the meaningful applications of diverse technologies in preclinical studies, focusing on the establishment of disease models and diagnostic techniques. Finally, we provide a comprehensive overview of clinical information using gene-editing therapeutics for treating various human diseases and emphasize the opportunities and challenges.

Addressing Conflicts of Interest and Conflicts of Commitment in Public Advocacy and Policy Making on CRISPR/Cas-Based Human Genome Editing

Leading experts on CRISPR/Cas-based genome editing-such as 2020 Nobel laureates Jennifer Doudna and Emmanuelle Charpentier-are not only renowned specialists in their fields, but also public advocates for upcoming regulatory frameworks on CRISPR/Cas. These frameworks will affect large portions of biomedical research on human genome editing. In advocating for particular ways of handling the risks and prospects of this technology, high-profile scientists not only serve as scientific experts, but also as moral advisers. The majority of them currently intend to bring about a "responsible pathway" toward human genome interventions in clinical therapy. Engaging in advocacy for such a pathway, they issue moral judgments on the risks and benefits of this new technology. They declare that there actually is a responsible pathway, they draft resolutions on temporary moratoria, they make judgments on which groups and individuals are credible and should participate in public and semi-public debates, so they also set the standards for deciding who counts as well-informed, as well as the standards of evidence for adopting or rejecting research policies. This degree of influence on public debates and policy making is, at the very least, noteworthy. This contribution sounds a note of caution with regard to the endeavor of a responsible pathway to human genome editing and in particular scrutinizes the legitimacy of expert-driven research policies given commercial conflicts of interest and conflicts of commitment among first-rank scholars.

Gene Editing of Hematopoietic Stem Cells: Hopes and Hurdles Toward Clinical Translation

In the field of hematology, gene therapies based on integrating vectors have reached outstanding results for a number of human diseases. With the advent of novel programmable nucleases, such as CRISPR/Cas9, it has been possible to expand the applications of gene therapy beyond semi-random gene addition to site-specific modification of the genome, holding the promise for safer genetic manipulation. Here we review the state of the art of ex vivo gene editing with programmable nucleases in human hematopoietic stem and progenitor cells (HSPCs). We highlight the potential advantages and the current challenges toward safe and effective clinical translation of gene editing for the treatment of hematological diseases.

In vivo delivery of CRISPR-Cas9 therapeutics: Progress and challenges

Within less than a decade since its inception, CRISPR-Cas9-based genome editing has been rapidly advanced to human clinical trials in multiple disease areas. Although it is highly anticipated that this revolutionary technology will bring novel therapeutic modalities to many diseases by precisely manipulating cellular DNA sequences, the low efficiency of in vivo delivery must be enhanced before its therapeutic potential can be fully realized. Here we discuss the most recent progress of in vivo delivery of CRISPR-Cas9 systems, highlight innovative viral and non-viral delivery technologies, emphasize outstanding delivery challenges, and provide the most updated perspectives.

The importance of genetic testing for dystonia patients and translational research

Genetic testing through a variety of methods is a fundamental but underutilized approach for establishing the precise genetic diagnosis in patients with heritable forms of dystonia. Our knowledge of numerous dystonia-related genes, variants that they may contain, associated clinical presentations, and molecular disease mechanism may have significant translational potential for patients with genetically confirmed dystonia or their family members. Importantly, genetic testing permits the assembly of patient cohorts pertinent for dystonia-related research and developing therapeutics. Here we review the genetic testing approaches relevant to dystonia patients, and summarize and illustrate the multifold benefits of establishing an accurate molecular diagnosis for patients imminently or for translational research in the long run.

CRISPR Gene-Editing Models Geared Toward Therapy for Hereditary and Developmental Neurological Disorders

Hereditary or developmental neurological disorders (HNDs or DNDs) affect the quality of life and contribute to the high mortality rates among neonates. Most HNDs are incurable, and the search for new and effective treatments is hampered by challenges peculiar to the human brain, which is guarded by the near-impervious blood-brain barrier. Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR), a gene-editing tool repurposed from bacterial defense systems against viruses, has been touted by some as a panacea for genetic diseases. CRISPR has expedited the research into HNDs, enabling the generation of in vitro and in vivo models to simulate the changes in human physiology caused by genetic variation. In this review, we describe the basic principles and workings of CRISPR and the modifications that have been made to broaden its applications. Then, we review important CRISPR-based studies that have opened new doors to the treatment of HNDs such as fragile X syndrome and Down syndrome. We also discuss how CRISPR can be used to generate research models to examine the effects of genetic variation and caffeine therapy on the developing brain. Several drawbacks of CRISPR may preclude its use at the clinics, particularly the vulnerability of neuronal cells to the adverse effect of gene editing, and the inefficiency of CRISPR delivery into the brain. In concluding the review, we offer some suggestions for enhancing the gene-editing efficacy of CRISPR and how it may be morphed into safe and effective therapy for HNDs and other brain disorders.

CRISPR/Cas9 for the treatment of haematological diseases: a journey from bacteria to the bedside

Genome editing therapies represent a significant advancement in next-generation, precision medicine for the management of haematological diseases, and CRISPR/Cas9 has to date been the most successful implementation platform. From discovery in bacteria and archaea over three decades ago, through intensive basic research and pre-clinical development phases involving the modification of therapeutically relevant cell types, CRISPR/Cas9 genome editing is now being investigated in ongoing clinic trials. Despite the widespread enthusiasm brought by this new technology, significant challenges remain before genome editing can be routinely recommended and implemented in the clinic. These include risks of genotoxicity resulting from off-target DNA cleavage or chromosomal rearrangement, and suboptimal efficacy of homology-directed repair editing strategies, which thus limit therapeutic options. Practical hurdles such as high costs and inaccessibility to patients outside specialised centres must also be addressed. Future improvements in this rapidly developing field should circumvent current limitations with novel editing platforms and with the simplification of clinical protocols using in vivo delivery of editing reagents.

Bioethical issues in genome editing by CRISPR-Cas9 technology

Genome editing technologies have led to fundamental changes in genetic science. Among them, CRISPR-Cas9 technology particularly stands out due to its advantages such as easy handling, high accuracy, and low cost. It has made a quick introduction in fields related to humans, animals, and the environment, while raising difficult questions, applications, concerns, and bioethical issues to be discussed. Most concerns stem from the use of CRISPR-Cas9 to genetically alter human germline cells and embryos (called germline genome editing). Germline genome editing leads to serial bioethical issues, such as the occurrence of undesirable changes in the genome, from whom and how informed consent is obtained, and the breeding of the human species (eugenics). However, the bioethical issues that CRISPR-Cas9 technology could cause in the environment, agriculture and livestock should also not be forgotten. In order for CRISPR-Cas9 to be used safely in all areas and to solve potential issues, worldwide legislation should be prepared, taking into account the opinions of both life and social scientists, policy makers, and all other stakeholders of the sectors, and CRISPR-Cas9 applications should be implemented according to such legislations. However, these controls should not restrict scientific freedom. Here, various applications of CRISPR-Cas9 technology, especially in medicine and agriculture, are described and ethical issues related to genome editing using CRISPR-Cas9 technology are discussed. The social and bioethical concerns in relation to human beings, other organisms, and the environment are addressed.