Ever since 2001, the year that the Human Genome Project was completed, personalized medicine has been a dream waiting to be turned into a reality. Personalized genomic medicine promises to do something that most drugs cannot do: instead of targeting a specific disease, these drugs are designed to target a specific disease-causing-mutation based on information found in a person’s DNA.
Though not all diseases are caused by a genetic mutation, drugs that target genetic pathways can be helpful to thousands of individuals. One example of a personalized genomic drug is Kalydeco, prescribed for people diagnosed with cystic fibrosis (CF). CF is a disease in which thick mucus surrounds the lungs and other organs, causing difficulty breathing and frequent infections in the lungs. The disease is autosomal recessive; meaning that a person is only affected if they have two copies of the gene causing CF. The disease is deadly in most cases and the average lifespan of an affected individual in the U.S. is only 37 years. CF affects around 30,000 people in the U.S., 70,000 worldwide, and has a higher frequency in the Jewish Ashkenazi population.
Cystic Fibrosis is caused by any one of many mutations in the CFTR gene that Kalydeco targets. A mutation in the CFTR gene causes limited chloride and sodium ions allowed to flow into a cell. This, in turn, causes thick, sticky mucus to develop in vital organs, which causes the defining symptoms of CF. Kalydeco targets the cause of the disease instead of merely targeting the symptoms, working to restore normal ion flow in cells, reverse mucus production, and thereby stop the coughing and frequent infections in the lungs. This is the reality of personalized genomic medicine—targeting a disease at its source is the most effective way of preventing further symptoms from occurring.
Kalydeco only works on specific mutations that cause CF. This amounts to around 2,000 patients under the drug’s treatment. Kalydeco and drugs like it are mainly effective against “orphan diseases,”—those diseases based on a mutation that affects only a small number of people, or a small subset of people that have a specific mutation, like CF. But for people that fall within this category, the Kalydeco drug is considered to be miraculous. A patient quoted in a recent New York Times article states, “I still pinch myself every day. I can take deep breaths. I can run without coughing…”
While the benefits of tailor-made drugs like Kalydeco are high, the costs are considerable, making them harder to market. Drugs like these cost more than $300,000 a year, amounting to millions of dollars over a patient’s lifespan. With these astronomical figures, scientists and consumers worry about the future. While few drugs like Kalydeco are currently on the market, this may change over the next few years. For example, there are talks of a personalized drug to treat hepatitis C, a disease that infects over 130 million people worldwide. The total treatment cost of that type of drug is almost unimaginable.
Personalized medicine will be medical care based on our very core, our unique genetic data. This will completely change how treatments are administered. Researchers are working toward a future where each of us will have the opportunity to get a blood test to have a complete analysis of the 20,000 coding-genes which is our personal genetic blueprint and will become a crucial piece of our medical record. It will tell your physician critical information, such as, what diseases are you likely to get? heart disease? colon cancer? arthritis? Alzheimer’s? What should be done to help prevent those diseases? exercise? yearly colonoscopy? drugs? gene therapy? Which treatments will work for you, as an individual, and which will harm you?
Personalized medicine is the future of medicine, and if we want to make this dream into a reality, costs will be high. But before worrying about those details, it’s important to acknowledge the tremendous strides made in the genetic and pharmaceutical fields that have brought us to where we are today, and to recognize how much we have yet to uncover.