ADVANCING HEALTHCARE WITH PERSONALIZED MEDICINES: Treatments Tailored to Your Genes

Understanding Personalized Medicine

 “Personalized Medicine (PM)” also known as “Precision Medicine” is an emerging practice of medical research. It tailors treatments to individual patients. It extends the traditional One-Size-Fits-All approach, predicting safe and effective treatments based on the patient’s genetic profile.

Crucial Components 

The concept of PM is not a novel one, it initially stemmed in the 1990s after the advances in DNA sequencing technology, including automation ensued. Pharmacogenetics, widely recognized as a fundamental step toward “personalized medicine”.  It is the study of how genes affect the way medicines work in our body. Pharmacogenomics, the use of genetic testing to guide drug treatment serve as the foundation for “personalized” healthcare.

Science Behind Personalized Medicine

You inherit your genes from your parents. These inherited genes, which serve as an instruction manual for your body to produce proteins and perform other necessary tasks. These genetic instructions encrypted in varying patterns of four bases, can vary between individuals due to gene variations, such as base substitutions or missing bases. This potentially increasing the risk of certain diseases or affecting the effectiveness of medications or their side effects.

Genetic testing done by doctors predict drug response and make informed medical decisions. For example, the TPMT gene test done in children with leukemia might help doctors choose the right dosage of medicine as well as to prevent toxic side effects. Note: The TPMT gene is responsible for creating the enzyme that breaks down thiopurine drugs (cancer treating drug).

“Providing ‘the correct drug, with the right dose at the right time to the right patient’ is the Personalized Medicine’s vision for the 21st century.”

Classic Examples of Early Personalized Medicines

Researchers linked early personalized medicines to genetically-mediated pharmacokinetic aspects of drugs, basing their influence on an understanding of drug-metabolizing enzymes.

• Warfarin, a blood thinning medication, targets the VKORC1 gene and is metabolized by CYP2C9. Genetic variation in these genes leads to varying pharmacodynamic and pharmacokinetic properties, causing adverse reactions. The US Food and Drug Administration recommends personalized dosing for warfarin based on an individual’s genotype.

• Primaquine (PQ) is another example of a drug that should only be given to individuals with a specific genetic profile. It has been used to manage malaria. In the olden days, military doctors observed some soldiers treated with malaria became jaundiced and anaemic. They ended up developing ‘acute haemolytic anaemia’ after administration of PQ. This was due to G6PD gene variants. Current clinical practice requires genotyping of individual patients to avoid potential side effects.

Merits & Benefits of Personalized Medicine

• PM can be used not only for illness treatment but also for early illness identification and prevention.

• It is a rapidly growing healthcare field that uses genetic profiling to select treatments for patients. This minimizes side effects and ensuring successful outcomes.

• It focuses on preventative medicine. This aid in reducing the need for more severe treatments and improving the effectiveness of existing treatments.

• This approach is less cost-effective than a ‘trial-and-error’ approach, contributing to rising healthcare costs.

• It can enhance medication selection, therapy, patient compliance, prevention and cost effectiveness.

Limitations & Challenges of Personalized Medicines

• A comprehensive understanding of an individual’s response to interventions in PM also requires a thorough grasp of disease molecular mechanisms. This complexity can make it challenging to fully characterize patients on multiple levels.

• Identifying cost-saving technology and protecting private information are burdensome.

• Challenges include scientific, economic, operational, and policy issues.

• PM faces challenges in obtaining regulatory approval and broad acceptance from healthcare stakeholders.

• Although the scientific community has long recognized the value of using genetic data to create personalized medicine, its benefits are not yet fully appreciated.

Expanding the Reach of Personalized Medicine

Personalized medicine is not necessary for all diseases. This is because many diseases lack significant genetic variability and doesn’t require personalized approach. Although researchers originally designed personalized medicine for rare genetic conditions like cystic fibrosis, it has important potential uses in other areas of medicine. Currently it’s most useful for fields like oncology, cardiology, and infectious diseases, where molecular diagnosis is crucial.

In concluding observation, we need to know that PM has the potential to improve health outcomes by reducing healthcare costs and drug development time; it requires equal participation from patients, innovators, regulators, physicians, academic researchers, IT sector, stakeholders, payers, and policymakers.

REFERENCES

(1) Urol Oncol. Author manuscript; available in PMC 2015 Feb 1. (2) Biomed Rep. 2017 Jul; 7(1): 3–5. (3) Fertil Steril. Author manuscript; available in PMC 2019 Jun 1. (4) Fertil Steril. 2018 Jun; 109(6): 952–963. (5) Cell Reports Medicine 3, 100530, February 15, 2022