Personalized Medicine: The New Frontier

Personalized Medicine: The New Frontier

Imagine having the ability to predict your body’s reaction to a drug before actually taking it. Could doctors have an inventory of all drugs that could either favorably or adversely react to their patients’ bodies, or even have no benefit at all, before prescribing treatment? What if every patient had an individual, molecular profile that allowed healthcare providers to better determine clinical therapies based on unique genetic and environmental information? The answer is yes; it’s possible with personalized medicine.  

Since April 2003, the hub of scientific knowledge has expanded exponentially due to the massive efforts of the Human Genome Project [1]. Decoding the human genome – the total set of 3 billion DNA base pairs that engineer the human blueprint – did much more than transform our understanding of the link between our inner genotype and outer phenotype [2]. At this point, the intricate detail of the human genome has the potential to revolutionize medicine. 

A report from Johns Hopkins University describes personalized medicine, also termed precision medicine, as the future and single most promising new standard of care, which has the power to revolutionize our existing one-size-fits-all, “Big Pharma” system [3]. The prevailing philosophy of the pharmaceutical industry has been to develop “blockbuster” drugs that treat the illnesses and diseases which affect the largest cohorts of people [3]. Not only do blockbuster drugs often come with a plethora of unwanted and sometimes severe side-effects, they also sustain the traditional idea of reactive versus proactive medicine. 

 Most people visit the doctor after they have signs or symptoms of an illness or disease, and drugs are then prescribed to broadly treat the symptoms as a reaction to the underlying problem. What are the limitations to this approach? A broad-based blockbuster drug will never react the same with everyone, because no two people are exactly the same. Even in the case of identical twins, the unique environmental experiences and outside factors for each person – such as diet or exposure to other drugs –  will have an impact on their expression of genes and the subsequent production of proteins in the body. The body’s proteome – its total database of proteins – is actually just as unique as the genome. Some people have slightly different structural variations and amounts of the same type of protein, while some do not express certain proteins at all [3]. This is significant, because most blockbuster drugs are designed to target a particular protein [3]. Consequently, adverse reactions to prescription drugs are often caused by variations in proteins or lack thereof. Every year up to 4.5 million people have adverse reactions to prescription drugs, causing nearly 400,000 hospitalizations and as much as $29 billion in healthcare costs [3]. 

This is the reason why personalized medicine and its proactive, patient-centered approach has so many incentives. Instead of a one-size-fits-all system, patients themselves can first be stratified based on individual predisposition to a disease, as well as their own risks, benefits, and responses to a particular drug [3]. In essence, personalized medicine shifts the traditional system of “Big Pharma” to “Big Data,” using the vast information bank of the human genome to inform both immediate and long-term medical decisions [3]. As Hippocrates predicted, “It's far more important to know what person the disease has than what disease the person has” [3]. 

How exactly will a person’s genetic information translate to practical clinical benefits? According to the Johns Hopkins report, the three core areas of impact to healthcare will be 1) better diagnosis, 2) earlier interventions, and 3) optimal therapies [3]. An exciting branch of clinical diagnostics is the relatively new concept of pharmacogenetics, which emphasizes the “one-size-fits-subpopulation” model of personalized medicine [3]. In addition to known family and clinical histories, pharmacogenetics uses a patient’s genetic profile to not only predict drug response, but to also inform the healthcare provider about the proper dosage of a particular medication [3]. The ability to prevent over- or under-dosing, which is a common problem when prescribing new drugs, also has real financial benefits [3]. For instance, clinical trials could be narrowed to reach more specific participant populations, leading to greater precision in patient response and outcome, as well as overall lower costs of R&D for pharmaceutical companies [3].    

Amidst strong clinical and financial benefits, equally important ethical concerns of genetic discrimination and misuse of genetic information have emerged. What if insurance companies or employers are able to access a person’s genetic profile and, as a result, increase premiums, prevent hiring, or breach general privacy? In an effort to prevent this from happening, the Genetics Information Nondiscrimination Act (GINA) became law in 2008 to ensure patient protection from these types of employer or insurance discriminatory practices [3]. Employers across the nation have implemented the regulations provided by GINA, while the increase of genetic privacy laws have been proactive in preventing workplace discrimination [3]. However, it’s essential that current policy and bioethics discussions on protection measures keep pace and evolve with the rapidly growing biotechnology sphere. This will be one of the biggest challenges moving forward. 

Just as policy has changed to face the direction of current scientific and medical advances, pharmaceutical companies have also begun to make targeted changes in favor of personalized medicine. For example, the cancer treatment drug called imatinib has been developed to benefit a relatively small cohort of patients by targeting specific proteins for inactivation [3]. Slowly but surely, efforts to create pharmacogenetic treatment plans are becoming more mainstream in pharmaceutical R&D, especially in cancer research and therapy. 

Cancer in particular has a promising future with personalized medicine. In fact, Breast cancer treatment has benefited greatly from pharmacogenetic analysis. One of the most commonly prescribed drugs for metastatic breast cancer, known as Herceptin, is actually only effective in treating 30% of patients due to abnormal overexpression of a certain protein called HER2 [3]. The remaining majority, an astounding 70% of patients with the same type of cancer, will not respond to the drug specifically because of their normal levels of HER2 [3]. Further efforts taken by the Center for Cancer Research are plan to investigate the genetic determinants of, rhabdomyosarcoma, a rare cancer found in children, using a personalized approach that will one day be able to directly link genetic mutations to cancer prognosis and best therapies [4].  

The increased accuracy and accessibility of pharmacogenetic assays for clinical practice will also play a key role in the success of personalized medicine. For the past decade, techniques for analyzing whole genomes and deciphering connections to specific drug interactions required the participation of several large research institutions and millions of dollars, which often created a barrier for larger implementation [4]. However, the tides are changing to engineer much faster, more affordable, and simpler biotechnologies capable of synonymous, if not more accurate, pharmacogenetic analysis [5, 6]. As a result, the detection, diagnosis, and prevention of diseases with mobile, point-of-care biotechnologies has become the new horizon for personalized medicine; this will become especially useful for developing nations and resource-limited settings that face challenges in treating chronic conditions and as infectious diseases [5, 6].      

In the future, personalized medicine will require interdisciplinary efforts to not only ensure critical bioethical discussions and patient protection, but also increased accessibility and reliability of pharmacogenetic assays across both rich- and low- resource settings. In his State of the Union address in 2015, former President Barrack Obama revealed the Precision Medicine Initiative, a program designed to establish concerted efforts on undertaking this very mission [7]. In his speech, he stated: “I want the country that eliminated polio and mapped the human genome to lead a new era of medicine –  one that delivers the right treatment at the right time” [8]. Today, his sentiment still holds true. Personalized medicine is the new frontier for modern health and ethics, which just might harbor the next great human discovery.     


References

  1. National Human Genome Research Institute. (1 Oct. 2015). All About The Human Genome Project (HGP). National Institutes of Health. Retrieved from https://www.genome.gov/10001772/all-about-the--human-genome-project-hgp/
  2. National Human Genome Research Institute. (30 Oct. 2010). The Human Genome Project Completion: Frequently Asked Questions. National Institutes of Health. Retrieved from https://www.genome.gov/11006943/human-genome-project-completion-frequently-asked-questions/
  3. Husick, L. A., et. al. (10 Apr. 2013). From the Bench to the Boardroom: Planning for Personalized Medicine. Johns Hopkins University, Managing Innovation in the Life Sciences, Center for Advanced Biotechnology Studies. Retrieved from http://advanced.jhu.edu/wp-content/uploads/2013/04/PersonalizedMedicineClassBook.pdf
  4. Center for Cancer Research. (2014). Seeing the Forest and the Trees. National Institutes of Health. Retrieved from https://home.ccr.cancer.gov/connections/2014/Vol8_No1/news_7.asp
  5. Sloane, H. S., et. al. (12 Dec. 2016). Warfarin genotyping with hybridization-induced aggregation on a poly(ethylene terephthalate) microdevice. Analyst, 142, 366. doi: 10.1039/c6an02325h
  6. Scherr, T. F., et. al. (27 Jun. 2016). Mobile phone imaging and cloud-based analysis for standardized malaria detection and reporting. Sci. Rep., 6, 28645. doi: 10.1038/srep28645
  7. Reardon, S. (22 Jan. 2015). US precision-medicine proposal sparks questions. Nature News. Retrieved from https://www.nature.com/news/us-precision-medicine-proposal-sparks-questions-1.16774
  8. The White House. (2015). The Precision Medicine Initiative. Retrieved from https://obamawhitehouse.archives.gov/node/333101
     
Interview with Dr. Flores Pt 1.

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