Gene Editing: Discovering New Cures
Breakthroughs in gene therapies could allow medicine to leap lightyears ahead and address some of the world’s most difficult diseases
Vaccines to fight disease. Genetically modified foods to address nutrition shortages. A sequenced human genome to improve medical practice. Breakthroughs in biotechnology have solved pressing societal challenges, to say the least. But among the many discoveries of the past 20 years, few may receive the same level of praise as gene editing.
Gene editing involves modifying an organism’s DNA to correct a previously malfunctioning mechanism in the body, such as the advancements made in treating sickle-cell anemia and cancer (discussed below). In addition to correction, gene editing can also be used for the production of needed proteins. For example, bacteria can be genetically modified to produce insulin.
Suffice to say, the applications for gene editing are wide-ranging, and are only going to become more impactful as this technology progresses. Let’s take a look at the developments happening now, and what we can look forward to in the next 2 years and beyond.
Now: Approved Gene Therapies Show Remarkable Promise
In December 2023, the first gene therapy to treat sickle cell disease was approved by the FDA. Sickle cell disease is a debilitating blood disorder that afflicts 100,000 people in the U.S., primarily those of Black or African American descent. Sickle cell disease occurs from a mutation in the protein “hemoglobin” which causes the protein to misfold and create a “sickle shape.” As a result, the misfolded hemoglobin isn’t able to properly deliver oxygen to the tissue, leading to severe pain and possible organ damage.
The gene therapy involved extracting cells from the bodies of patients, altered them with gene editing, then putting them back into the body, where they multiply with the corrected genetic code. For the sickle cell patients that went through the treatment, 93.5% were free from a severe sickling event for 12 consecutive months.
Gene therapies have even had impressive results in treating cancer. For the gene therapy approved for Acute Lymphoblastic Leukemia (ALL), 93% of patients responded well initially and 73% achieved remission for over 2.5 years. Another gene therapy for treating B-cell lymphoma, a different form of cancer, showed significant improvements in the overall survival rates as compared to standard care. These rates of improvements from gene therapies have outpaced results from traditional treatments like chemotherapy and radiation, leading to a promising future for medical breakthroughs.
Though gene therapies cure complex diseases at high rates of efficacy, they have drawbacks. Because these therapies are “autologous”— meaning that the patient’s own cells are taken, modified, and transplanted back into the body— they can be quite difficult treatments for already sick patients to endure. Further technology improvements are needed to make this remarkable therapy more accessible, and fortunately they are on the way.
New: Beyond Autologous Treatments
Two main factors hinder the ability to administer gene therapy treatments: 1) they are autologous, thus limited to the cells of the patient, and 2) extensive processing is done to the immune cells before they are transferred into the body, making the process both time-consuming and expensive. But additional applications of gene editing are beginning to solve these limitations.
Imagine that all your cells contain some sort of digital ID, a specialized genetic fingerprint specific to you. If you ever tried to take cells from a different person and put them in your body, your immune system would immediately flag the cells as foreign and try to destroy them because they weren’t carrying the right ID specific to your body. This is how the body functions in reality.
Each of our cells carry individual protein markers that distinguish them from another person’s cells. Typically, transferring healthy cells from one person to another would illicit the recipient’s immune response and cause the body to reject the foreign cells. But with gene editing, we can remove all the identifying information of immune cells before they are transplanted into the patient. This would result in any healthy patient being able to donate their immune cells to a patient in need.
Having such “immune cell donors” for genetic therapies can help cut down on the long processing timelines and high costs I mentioned earlier. As a result, therapies using this technology for sickle cell and other diseases are already showing great promise in the clinic, with several candidates in phase II trials. As the technology progresses, other complicated matching procedures, like organ transplantation, could become smoother. Transplant waitlists may even become a relic of the past.
Next: Next Generation Advancements in Genetic Editing Capability
Gene editing thus far has shown great promise in correcting specific or localized mutations within the genetic code. Hopefully, over the next decade, gene editing can advance to replace larger stretches of genetic information with the same precision of today’s technology.
For example, devastating diseases with no current cures, like Huntington’s, have more complicated stretches of incorrect genetic information than diseases like sickle cell. The mutation for Huntington’s leads to the progressive breakdown of nerve cells in the brain and body which leads to physical difficulties and cognitive decline. Currently, gene editing tools are not able to modify larger mutations like those for Huntington’s, but promising technologies like prime editing could rectify these diseases therapeutically in the future.
Prime editing technology acts like a find and replace tool, with the ability to search any gene, remove the incorrect data and replace with the correct sequence. This still requires a great deal of optimization before it is commercially viable as a therapeutic solution, but prime editing could have a profound effect on some of the world’s most debilitating genetic diseases.
Conclusion: Looking Further Forward
There is no question that the advancement of modern medicine has made our world healthier, with life expectancy higher today than ever before in human history. However, the efficacy rates in today’s pharmaceuticals that are most accessible to the population pale in comparison to the rates of recently developed gene therapies.
The advancement of gene editing can be one of the keys to unlocking the widespread usage of these more costly and rare therapies. A combination of the increased ability to modify our own genetic code, along with clever manufacturing techniques, will help us reimagine a world where some of the most daunting diseases of today can have a specific and effective cure in our tomorrow.
Nkechi Nwokorie | Emerging Tech Consultant, Deloitte