While it is still a work in progress and considered experimental, gene therapy has the potential to be a medical “miracle-worker”, curing a multitude of diseases such as cancer, heart disease, diabetes, muscular dystrophy, cystic fibrosis, HIV/AIDS and other hereditary disorders. The current results are still limited but the promise gene therapy holds for the future is monumental in the fight to save lives, cure disease and extend life expectancy.
Why is gene therapy important?
Gene therapy is, in a nutshell, the introduction of DNA into cells as a drug, to rectify the effects of mutated genes within the body, working directly and with precision to fix the mutation and thus treat the disease. Also known as human gene transfer, gene therapy is very different from other treatments available as it aims to heal genetic malformations, changing the course of a disease altogether, doing more than just treating it.
Another fascinating promise in this field of study comes from the distinction between two classifications of gene therapy – Somatic gene therapy and Germline gene therapy. Whereas in Somatic gene therapy, the DNA is integrated into cells such as bone marrow but not into reproductive cells, Germline gene therapy introduces DNA into reproductive cells, therefore having the ability to modify the genome, making the changes heritable to the patient’s future children. Thus, Germline gene therapy can potentially help to permanently eliminate certain inherited diseases. While this sounds extremely promising, it is important to note that these technologies are still in experimental stages and due to the insufficient knowledge regarding risks and ethical reasons, Germline gene therapy is still a very sensitive topic and in most countries it is currently prohibited from use in humans.
Where gene therapy science stands today
Currently, the focus of clinical trials is to bring to market treatments for rare diseases. Many of these are being coordinated by the U.S. Food and Drug Administration (FDA). However, only a limited number of gene therapy products have been approved for sale in the United States.
One example of clinical trials being conducted include a joint research in gene therapy for β-thalassemia. This disease is a blood disorder characterised by a deficiency in the production of hemoglobin in adults and the clinical trial suggests that by splitting a certain gene, patients undergoing the treatment should be able to produce enough hemoglobin to mitigate the effects of their disorder.
Another research is focusing on treatment for Spinal Muscular Atrophy (SMA), a genetic disease affecting the part of the nervous system that controls voluntary muscle movement. The trial found that patients suffering from SMA are either missing or having a mutated gene called the Survival Motor Neuron 1 (SMN1) gene. The missing or mutated gene can be replaced using a viral transportation mechanism to insert a corrected gene.
Key challenges for gene therapy and what the future holds
Even though the field of gene therapy is making big advances, all research still faces three major challenges on a therapeutic level. The precession for gene therapy, so that the new gene reaches the right cell; avoiding a suppressive reaction from the immune system, as it is designed to fight off foreign intruders into the body; and making sure that the new gene does not disrupt the functioning or efficiency of other present genes.
But perhaps the biggest challenge in the field of gene therapy are the financial costs. Gene therapy comes with an expensive price tag as many hereditary diseases that could be targeted with gene therapy are exceptionally rare and require an individualised case-by-case approach.
These challenges are common to most medical treatments in their infancy and over-time gene therapy will become more accessible and will redefine, the way we approach and treat a variety of medical conditions.