Personalized Medicine is one of the leading trends in the world of medicine today. It espouses basing diagnoses and treatments on the genetic profiles of the patient and the disease. This innovative approach is founded on the understanding that treatments adapted to the patient’s unique characteristics and condition may improve the chances of recovery. Such adaptation shall also aid in reducing the side effects resulting from the use of broad-scope drugs that affect the entire body and not just the affected cells.
The tremendous advancement in developing personalized treatments was made possible thanks to the Human Genome Project launched in 1990, the results of which were first published in 2003. Under its scope, the sequencing of human DNA has been completed, and about 25,000 genes have been mapped. Over the twenty years that have passed since many novel DNA sequencing technologies have been developed, it is now possible to determine a “genetic ID” for any patient and specific diseases within a few weeks and at a low cost.
Genetic Medication for Cancer
The personalized medicine approach is utilized even today for a wide variety of oncologic diseases, chronic diseases, and rare syndromes.
Thus, for instance, over the past five years, treatment with PARP inhibitor drugs has been approved for patients with breast cancer, ovarian cancer, pancreatic cancer, and prostate cancer with harmful alterations in the BRCA gene. These drugs have a unique mechanism of action, preventing DNA damage repair in cancer cells with BRCA mutations, thus destabilizing the cells and impeding their ability to survive. The use of PARP inhibitors demonstrated a benefit in delaying the spread of these diseases, and on March 2022, analysis of data from a major clinical study has proven that their use in patients with metastatic BRCA-positive breast cancer was life-prolonging.
Gene Therapy for a Hereditary Muscle Disease
Another breakthrough was achieved in children with a hereditary disease named SMA, which leads to progressive muscle weakness as a result of nerve atrophy. The disease is typically caused due to deletion of broad sections of DNA in the SMN1 gene, which normally produces a protein that is important to the nerves responsible for muscle function. The disease typically appears during infancy and early childhood, and leads to paralysis and respiratory muscle damage over time.
In May 2019, the drug Zolgensma® was approved for use. This drug works by inserting a vector which carries a normal SMN1 into the relevant area of the cells, which produces the missing protein in the affected children. Several clinical studies which tested the new drug have found it to be highly effective, improving function in the patients who received it even in early infancy – to the point that these children could sit down, stand up, walk, and breathe independently and without assistance.
Genetic Medicine in the Future – Prevention, not just Treatment
The understanding that certain alterations in DNA may have a crucial meaning in the development of various diseases, and the need to develop personalized treatments to address these specific alterations, led to the development of a new and important concept – gene therapy. This concept is already partially implemented in treating certain diseases, such as the above-mentioned drug Zolgensma, which inserts a healthy gene into the body and compensates for the protein deficit.
CRISPR, a new technology that has been in development in recent years, seeks to successfully prevent the emergence of diseases in advance by editing DNA all the way back at the embryonic stage. CRISPR identifies pre-defined areas with DNA mutations and attaches to them. A protein named Cas9 attached to CRISPR functions as “scissors”, cutting out the problematic area that was identified. After the cut is made, the body’s natural DNA repair mechanisms complete the missing segment, or a normal segment that was pre-manufactured in a laboratory is inserted instead.
This innovative technology is already being tested in several preliminary clinical studies, testing its ability to treat a variety of diseases, such as type-1 diabetes, multiple myeloma, and sickle-cell anemia.
In Summary
DNA sequencing and the mapping of the human genome have opened a window to a better understanding of various diseases, and clarified the understanding that despite the great deal of similarity between individuals, the seemingly minor differences in DNA are, indeed, significant, and important to address. We anticipate that personalized medication shall gradually take up a more substantial part of the work with – and for – patients, and the day where we could match a “Genetic ID” to each patient, permitting treatment that matches them exactly, is not a long way away at all.
