Gene therapy is an experimental technique that treats patients
by inserting genes into their cells instead of using drugs or surgery.
By Michael Megarit
Gene Therapy Is Revolutionary And Could Be The Future Of Healthcare
There are more than 7,000 rare diseases which affect an estimated 320 million people worldwide. Of these rare and inherited conditions, 80% are genetic in nature.
This suggests that it may be possible to prevent, treat and cure these diseases by intervening on a cellular and genetic level.
Indeed, by targeting malfunctioning cells, doctors could splice the human genome and treat patients with a single procedure, eliminating the need for lifelong medical attention.
Imagine being able to cure Parkinson’s, sickle cell anemia and certain types of cancer with a single injection of a next-generation viral-vector.
This is the promise of gene therapy.
What are Genes?
To understand gene therapy, we must first explain how cells and genes function.
Cells are the basic building blocks of all living things. Our bodies are made up of trillions of different kinds of cells that perform different functions. For example, white blood cells help the body fight off infections and diseases while red blood cells carry the oxygen we breathe around the body.
Hidden inside our cells is a molecule called DNA. A gene is simply a small section of DNA that contains instructions that tell our cells to produce proteins. Proteins perform various tasks such as powering muscles and attacking invading bacteria. In a word, they keep us healthy.
Unfortunately, genes are fragile.
They can be damaged either naturally or by inherited mutation. When that happens, the gene is unable to transmit the information that produces proteins. As a result, damaged cells are unable to ensure proper bodily function, which can lead to the formation of diseases.
For example, people with a variant hemoglobin gene have red blood cells with an abnormal shape. Consequently, the flow of oxygen is slowed, blood flow is blocked, and the patient experiences pain, swelling, infections and even vision problems. This is a common disease called Sickle Cell Anemia.
Is it possible to treat such diseases by manipulating the human genome?
Gene therapy is a scientific technique that attempts to do just that.
What is Gene Therapy?
Gene therapy is an experimental treatment that involves correcting or replacing a person’s mutated or malfunctioning genes. When performed correctly, it prevents and treats diseases in various ways:
- Replace a damaged, “mutated” gene that causes disease with a healthy copy of the gene.
- Inactivate a malfunctioning gene.
- Introduce a new gene to fight a disease or restore normal function.
Currently, gene therapy is used for conditions in which somatic cells (cells that are not egg and sperm cells) have experienced a change in genetic coding. To correct the disease in which a particular enzyme is missing, it is possible to inject the necessary gene component that will trigger the production of the missing enzyme and cure the disease.
In most cases, a harmless virus is used as a packet to carry the new gene to where it is needed. Once the gene is correctly placed, it switches on and provides the instructions for correct cellular function.
If everything goes to plan, the damaged gene is corrected and the patient is cured.
Gene Therapy is Still an Experimental Technique
To date, 22 cellular and gene therapy products have been approved by the US Food and Drug Administration (FDA).
However, gene therapy is still an experimental technique with no guarantees of systematic success.
The main challenge is to translate small breakthroughs into large-scale production processes that can be repeated thousands of times and reliably produce the same results in different patients.
While this represents a significant challenge, there is evidence suggesting that gene therapy is making significant progress.
CRISPR Gene Editing
The most advanced form of gene therapy is called Clustered Regularly Interspaced Short Palindromic Repeats – or CRISPR.
It is a genome-splitting tool that makes it possible to snip out disease-causing mutations and potentially cure a wide range of genetic diseases.
In November 2018, Chinese scientist Jiankui claimed he had successfully used CRISPR to permanently alter the genomes of twin girls to immunize them against HIV infection. This experiment sent shockwaves throughout the scientific community because Jiankui modified the twins’ cells when they were embryos, meaning that all of their cells are now modified, including their reproductive ones, which means they might pass on their edited genomes to their children.
While the long term effects of such profound genetic modifications are unknown, this extreme experiment illustrates how powerful and life changing CRISPR technology can be.
Other companies are using CRISPR to perform arguably less controversial gene therapy.
In July 2019, pharmaceutical companies Editas Medicine and Allergan announced that were conducting their own gene therapy trials. Their objective is to fix a cellular mutation that causes congenital vision diseases. This clinical trial focuses on editing somatic cells, which means that the modified genes won’t be passed on to the next generation.
Scientists conducting this study, will introduce CRISPR into the patients’ eyes. They hope this will repair the genetic mutation, restore the normal protein and enable them to sense light. Ultimately, the goal is to restore the patients’ vision.
In March 2020, the firms revealed dosing of the first patient. In January 2021, it was revealed that the patients experienced significant vision improvement as they were able to navigate an obstacle course at differing light levels.
Another example of gene therapy is Vertex Pharmaceuticals and CRISPR Therapeutics’ clinical trial that involves treating blood diseases. This experiment involves treating the patients’ cells outside of their body and reintroducing them back into the body. The theory is that the new healthy cells will outnumber the diseased cells.
In June 2021, new results from the study revealed that all of the 22 participants responded to treatment, free of blood transfusions and pain crises that respectively characterize their usual experiences with beta thalassemia and sickle cell. These positive results could lead to a submission for full approval of the treatment come by mid-2023.
Gene Therapy can Revolutionize Healthcare
Clearly, gene therapy has the potential to revolutionize healthcare.
The main problem with traditional healthcare is that it is mostly reactive. Doctors diagnose and treat patients in the later stages of disease and most health systems are built on treatments for chronic conditions. Thus, doctors prescribe drugs and treatments that target proteins, not genes.
The shortfall of this approach is that it targets the consequences of the disease rather than the root cause. Gene therapy opens the possibility of targeting the source of the disease.
One advantage of this approach is that it could rationalize the cost of healthcare.
Traditionally, healthcare costs are born over several years, sometimes decades. In some cases, patients are prescribed lifelong treatments. The costs of such treatments are often very high and often difficult to support for people with modest financial means.
Gene therapy could change the paradigm by putting the cost of diagnosis, cure and prevention up-front. Treatment would be considered an investment to prevent the development of chronic diseases and ultimately enjoy a better quality of life. Scientists would analyze a patient’s genes, identify malfunctioning or mutated genes and prescribe single-shot viral vectors that would solve the problem forever.
However, in order for this to work, healthcare systems will have to adapt.
Governments and private insurers will have to accept this change of paradigm and review their payment models to ensure that gene therapy would be accessible and affordable for patients and providers.
The Future of Gene Therapy
For now, gene therapy is focused on treating monogenic disorders, diseases caused by the mutation of a single gene.
However, scientists are already thinking about using gene therapy to tackle multifactorial inheritance disorders, where multiple defective genes contribute to the creation of a disease. Such diseases include Diabetes, Alzheimer’s, Schizophrenia, Eczema, and breast, ovaries, bowel, prostate and skin cancer, among others. The main challenge will be successfully fixing or replacing a number of defective genes without creating undesired side-effects.
Another area of study involves individualized treatments. Scientists believe they will soon be able to use programmed genes for the production of protein and antibody treatments against chronic disease. Simply put, this means that it would be possible for protein therapies to be “manufactured” directly in your body.
Despite the exciting and revolutionary potential, gene therapy is far from being a finished product.
For now, genome editing is usually limited to somatic cells, to ensure that genetic changes are not passed on from one generation to the next.
As we saw with Jiankui’s experiment, ethical concerns arise when genome editing is applied to germline cells, namely egg and sperm cells, or in the genes of an embryo. In that case, gene editing could be passed on to future generations, and the long-term effects of such a practice are still unknown.
Is this ethical?
Furthermore, gene editing may eventually go well beyond simply curing diseases.
In fact, it has the potential to radically increase human abilities.
Would it be permissible to use gene editing technology to enhance human traits? Is it morally acceptable to reserve these treatments to patients who can afford it? Will this create inequality between biologically upgraded humans and “normal” humans?
While we are still far from these scenarios becoming a reality, it is undeniable that gene therapy is only just beginning to revolutionize our vision of healthcare.
About the Author
Michael Megarit is a partner with Cebron Group.
With over 25 years of domestic and international corporate finance experience,
he provides M&A and capital advisory to high-growth technology companies.