In May 2019, the U.S. Food and Drug Administration (FDA) approved the first gene therapy designed to treat young children with spinal muscular atrophy (SMA), a leading genetic cause of infant mortality. The approval is the latest in a wave of advanced treatments known as cell and gene therapies, which, when described, often sound more like science fiction than reality.
A person’s genes can affect the likelihood he or she will contract certain conditions, including heart disease, diabetes, Alzheimer’s or addiction. However, genetic defects can also be the original cause of disease. In some cases, including hemophilia, cystic fibrosis, SMA and various forms of blindness, these defects appear at birth. In other cases, such as cancer, genetic mutations occur in time.
Historically, treating genetic disease has been incredibly challenging, but due to advancements in biopharmaceutical research, this has been changing. Scientists today have a much better understanding of the role genes play in causing or preventing disease, as well as how to edit, add or remove genes in a person’s cells.
Two areas have emerged from this growing body of research:
- Cell therapy represents the introduction of new cells into a patient’s body to grow, replace or repair damaged tissue in order to treat a disease. These treatments can use cells from the patients’ own body or from a donor. In some cases, such as CAR-T, cells are genetically modified before being reintroduced into the patient.
- Gene therapy, which includes the recently approved treatment for SMA, seeks to modify or introduce genes into a patient’s body with the goal of treating, preventing or potentially curing a disease. Examples of gene therapy include replacing a mutated gene that causes disease with a functional copy; or introducing a new, correct copy of a gene into a patient’s cells. To ensure a person’s body will accept these treatments, gene therapies must be packaged in a delivery vehicle, often deactivated viruses, to target the correct cells and deliver the genetic material into the cells’ genes.
Cell and gene therapies are the culmination of an enormous body of research dating back to the 1980s. Moreover, these advanced treatments have the potential to cure previously incurable diseases and to fundamentally alter the trajectory of many other life-threatening conditions, including many rare diseases. In fact, more than 70% of the gene therapies in development are for rare diseases.
Even with recent milestones, the field of cell and gene therapy remains in its infancy, and the possibilities are almost limitless. According to a 2018 report, scientists at America’s biopharmaceutical companies are developing nearly 300 cell and gene therapies to treat cancers, neurological diseases and more.