Gene Therapy

Gene therapy drugs and products are non-classic bioproducts designed and established for precision and/or personalized medicine. Gene therapy drugs are developed primarily based on the non-viral or modified-viral tools to restore the function of the missing or defective genes in the target cells. To develop genetically modified (GM) cell products, the target cells are isolated, genetically engineered via a viral vector, mainly lentiviral or retroviral vectors, and then transplanted into the patients. Gene therapy products are applied for a variety of genetic diseases, including monogenetic disorders and certain deadly cancers. Currently, 33 gene therapy drugs or products have been approved by the FDA or relevant authorities. Most of these biproducts are present in the clinic and market. Moreover, dozens of novel gene therapy products are being examined for rare and common inherited diseases as well as cancers in gene therapy clinical trials. Interestingly, the development and commercialization of gene therapy drugs have increased throughout the years. Emerging novel genetic tools for gene manipulation and delivery as well as the maturation and improvement of the former genetic tools play a fundamental role in developing gene therapy drugs. This chapter will focus on the history of discovery, mechanism of action, pharmacokinetics and pharmacodynamics, dosage, and administration of the approved gene therapy drugs and products. Their safety, adverse reactions, and treatment challenges are also discussed.