Recommendations for Regulating the Environmental Risk of Shedding for Gene Therapy and Oncolytic Viruses in Canada

Viral Vectors in Gene Replacement Therapy

Throughout the years, several hundred million people with rare genetic disorders have been receiving only symptom management therapy. However, research and development efforts worldwide have led to the development of long-lasting, highly efficient, and safe gene therapy for a wide range of hereditary diseases. Improved viral vectors are now able to evade the preexisting immunity and more efficiently target and transduce therapeutically relevant cells, ensuring genome maintenance and expression of transgenes at the relevant levels. Hematological, ophthalmological, neurodegenerative, and metabolic therapeutic areas have witnessed successful treatment of hemophilia and muscular dystrophy, restoration of immune system in children with immunodeficiencies, and restoration of vision. This review focuses on three leading vector platforms of the past two decades: adeno-associated viruses (AAVs), adenoviruses (AdVs), and lentiviruses (LVs). Special attention is given to successful preclinical and clinical studies that have led to the approval of gene therapies: six AAV-based (Glybera® for lipoprotein lipase deficiency, Luxturna® for retinal dystrophy, Zolgensma® for spinal muscular atrophy, Upstaza® for AADC, Roctavian® for hemophilia A, and Hemgenix® for hemophilia B) and three LV-based (Libmeldy® for infantile metachromatic leukodystrophy, Zynteglo® for β-thalassemia, and Skysona® for ALD). The review also discusses the problems that arise in the development of gene therapy treatments, which, nevertheless, do not overshadow the successes of already developed gene therapies and the hope these treatments give to long-suffering patients and their families.

ATMP Environmental Exposure Assessment in European Healthcare Settings: A Systematic Review of the Literature

Since 2007, a new class of biologic products for human use called "advanced therapy medicinal products (ATMP)" have been legally integrated in the European Medical Agency. They consist of recombinant nucleic acid, engineered cells, cells, or tissues. In the United States, ATMP fall under the regulatory framework of biological products and the term "cell and gene therapy product" is used in the legislative and regulatory documents. Potential clinical applications are broad, particularly, in the field of cancer, inherited genetic disease, and regenerative medicine. Indeed, the benefit conferred by CD19 chimeric antigen receptor T cells led to the first engineered cell therapy products to be approved by the Food and Drug Administration (FDA) in 2017. Gene therapy products to treat orphan diseases are also extensively developed with many clinical trials ongoing in the world. Nevertheless, the use of these therapeutic products is complex and requires careful considerations in the terms of regulatory and hospital setting requirements, such as storage, handling, administration, and disposal which justify the implementation of a secured medication circuit. Through this systematic review of the literature, the authors wanted to compile data on the assessment of environmental exposure related to the use of ATMP in healthcare setting to secure their medication circuit. A literature search was conducted on PubMed and Web of Science, and 32 publications dealing with environmental exposure assessment and ATMP were selected. In addition, marketed ATMPs were identified and data regarding the environmental concerns were extracted from product information sections from European Public Assessment Reports (EPAR). The environmental contamination assessments were mainly addressed in the reviews rather than in original articles related to the use of ATMP. Most of the product information sections from EPAR suggested precautions rather than requirements when dealing with environmental consideration following ATMP handling. Nevertheless, these precautions usually remain elusive especially concerning waste disposal and the detection of biological material on the work surfaces, and mainly relate to the genetically modified organisms (GMO) over non-GMO cellular products. Pharmaceutical oversight and adherence to the good preparation practices and good clinical practices are essential to ensure the safe use in term of environmental concern of these new therapeutic products in healthcare setting.

Safeguards for Using Viral Vector Systems in Human Gene Therapy: A Resource for Biosafety Professionals Mitigating Risks in Health Care Settings

Introduction

Health care workers who work daily with human body fluids and hazardous drugs are among those at the highest risk of occupational exposure to these agents. The Occupational Safety and Health Administration's (OSHA) Bloodborne Pathogens Standard (29 CFR 1910.1030) prescribes safeguards to protect workers against health hazards related to bloodborne pathogens. Similarly, the United States Pharmacopeia General Chapter 800 (USP <800>), a standard first published in February 2016 and implementation required by December 2019, addresses the occupational exposure risks of health care workers at organizations working with hazardous drugs. With emerging technologies in the field of gene therapy, these occupational exposure risks to health care workers now extend beyond those associated with bloodborne pathogens and hazardous drugs and now include recombinant DNA. The fifth edition of the Biosafety in Microbiological and Biomedical Laboratories (BMBL) and the National Institutes of Health Guidelines for Research Involving Recombinant or Synthetic Nucleic Acid Molecules (NIH Guidelines) mostly govern work with biohazardous agents and recombinant DNA in a laboratory research setting. When gene therapy products are utilized in a hospital environment, health care workers have very few resources to identify and reduce the risks associated with product use during and after the administration of treatments.

Methods

At the Abigail Wexner Research Institute at Nationwide Children's Hospital, a comprehensive gap analysis was executed between the research and health care environment to develop a program for risk mitigation. The BMBL, NIH Guidelines, World Health Organization Biosafety Manual, OSHA Bloodborne Pathogens Standard, and USP <800> were used to develop a framework for the gap analysis process.

Results

The standards and guidelines for working with viral vector systems in a research laboratory environment were adapted to develop a program that will mitigate the risks to health care workers involved in the preparation, transportation, and administration of gene therapies as well as subsequent patient care activities. The gap analysis identified significant differences in technical language used in daily operations, work environment, training and education, disinfection practices, and policy development between research and health care settings. These differences informed decisions and helped the organization develop a collaborative framework for risk mitigation when a gene therapy product enters the health care setting.

Discussion

With continuing advances in the field of gene therapy, the oversight structure needs to evolve for the health care setting. To deliver the best outcomes to the patients of these therapies, researchers, Institutional Biosafety Committees, and health care workers need to collaborate on training programs to safeguard the public trust in the use of this technology both in clinical trials and as FDA-approved therapeutics.

Market access of gene therapies across Europe, USA, and Canada: challenges, trends, and solutions

This review can inform gene therapy developers on challenges that can be encountered when seeking market access. Moreover, it provides an overview of trends among challenges and potential solutions.

Viral Vector Systems for Gene Therapy: A Comprehensive Literature Review of Progress and Biosafety Challenges

INTRODUCTION

National Institutes of Health (NIH) defines gene therapy as an experimental technique that uses genes to treat or prevent disease. Although gene therapy is a promising treatment option for a number of diseases (including inherited disorders, some types of cancer, and certain viral infections), the technique remains risky and is still under study to make sure that it will be effective and safe.

METHODS

Applications of viral vectors and nonviral gene delivery systems have found an encouraging new beginning in gene therapy in recent years. Although several viral vectors and nonviral gene delivery systems have been developed in the past 3 decades, no one delivery system can be applied in gene therapy to all cell types in vitro and in vivo. Furthermore, the use of viral vector systems (both in vitro and in vivo) present unique occupational health and safety challenges. In this review article, we discuss the biosafety challenges and the current framework of risk assessment for working with the viral vector systems.

DISCUSSION

The recent advances in the field of gene therapy is exciting, but it is important for scientists, institutional biosafety committees, and biosafety officers to safeguard public trust in the use of this technology in clinical trials and make conscious efforts to engage the public through ongoing forums and discussions.