Genomics and Personalized Medicine

 

GENOMICS AND PERSONALISED MEDICINES:

As each individual has a unique genome, genetic disorders are also unique for a particular patient in most of the cases. It is possible to identify the regions of mutation if the sequence of a patient’s DNA is known. These mutations can then be corrected by gene therapy. The gene therapy provided will obviously be unique to each patient. Hence, these are known as personalised medicines.

In personalised medication, apart from a medicine’s effect on a disease, medication is also given on the basis of their interaction with the patient’s genome.

 

HOW DID PERSONALISED MEDICINE GAIN MOMENTUM?

In 1902, Sir Archibald Garrod made the first connection between genetic inheritance and susceptibility to a disease (called alkaptonuria). About half a century later, in 1956, the first discovery of a genetic basis for selective toxicity was made (for the antimalarial drug primaquine). In 1977, the discovery of cytochrome P450 metabolic enzymes and their role in chemically altering drugs so they can be eliminated from the bloodstream led to the realization that variation in these enzymes can have a significant influence on the effective dose of a drug. Yet, the real drive towards personalized medicine began in 2003 with the complete sequencing of the human genome. We are now moving beyond the genome into the entire spectrum of molecular medicine, including the proteome, metabolome, and epigenome.

 

IDENTIFYING AND TREATING CANCERS

 

Genomic information has “opened our eyes” to the diverse characteristics of cancers and helped inform advances in drug development.

 

Cancer in two different individuals is not always same, there may be some part of the sequence of specific cancer in a particular patient that makes it different from the cancer of another patient. This explains why chemotherapy isn’t successful for all cancer patients. – “More and more in what we’ve learned is that tumours have certain mutations in common that make them more responsive or non-responsive to chemotherapy.”

Advances in genomic and genetic screening can also help identify the presence of cancer, particularly cancer recurrences, earlier and with less invasive methods. And help medical practitioners assess a specific individual’s health risks.

 

CHECKING THE RECURRENCE OF CANCER:

Often, the only way of  diagnosing the recursion of cancer is through X-ray or an MRI. Or undergo unpleasant procedures like cystoscopy. But with advancements in the field of genomics, now, there are tools where, for instance, you look at the cancer cells in the urine, The urine test, which measures three distinct DNA methylation markers, detected tumor recurrence with both high sensitivity and specificity (80% sensitivity and 97% specificity) in NMIBC patients.

Health care systems, more and more, are setting up sequencing facilities, or turning to independently owned facilities, to conduct this type of work.

 

ADVANTAGES OF PERSONALISED MEDICATION:

Personalised treatment has turned out to be a great boon as it:

  • Shifts the emphasis in medicine from reaction to prevention
  • Directs the selection of optimal therapy and reduce trial-and-error prescriptions 
  • Helps avoid adverse drug reactions
  • Increases patient adherence to treatment
  • Improves quality of life
  • Reveals additional or alternative uses for medicines and drug candidates.

 

DEVELOPING AN ETHICAL AND LEGAL FRAMEWORK FOR GENOMICS

 

As this work continues to jump from academic research labs into the mainstream, certain ethical, legal, and policy implications arise. We do have a number of policies around the globe for the same reason.

 

If it is known that someone is genetically predisposed to a certain disease, it could lead to employment and insurance discrimination. To avoid this situation, United States has the Genetic Information Nondiscrimination Act that aims to protect people against such a discrimination.

 

And there are many other propositions like:

 

  1. There are challenges we have to be aware of in terms of what information we want to know about our genome and what kind of information is not ready for us to learn about – for instance when there is nothing to do for someone who has a predisposition to a devastating disease.
  2. Also, policies should be established surrounding who has the right to make decisions based on our human genome.
  3. Issues such as privacy, informed consent, and intellectual property all come into play as genomic research and technology move forward.
  4. Accessibility is another techno-economical issue. There’s still a long way and a lot of work to do in bringing technologies to a lower cost, so they are accessible to everyone.

References-

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/503689/Healthcare_UK_Genomics__Personalised_Medicine__DIGITAL.pdf

http://www.futuremedicine.com/doi/abs/10.2217/pme.11.86

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3641662/

https://ecpe.sph.harvard.edu/newsstory.cfm?story=Real-World-Genomics

http://www.personalizedmedicinecoalition.org/Userfiles/PMC-Corporate/file/pmc_the_case_for_personalized_medicine.pdf

Understanding Personalized Medicine: Drug Development and Usage

Every day, millions of people are taking medications that will not help them. The drugs currently being prescribed are optimally beneficial to as few as 4% of the population consuming them. The realization that physicians need to take individual variability into account is driving huge interest in ‘precision’ medicine or Personalized medicine. In this time of technological advancements and unprecedented scientific breakthroughs, personalized health care has the ability to look at a patient on an individual basis so as to detect the onset of disease at its earliest stages, and at the same time increase the efficiency of the health care system by improving quality, accessibility, and affordability.

Every person has a unique genome and personalized medicine relies on technologies that confirm a patient’s biology at the molecular level with DNARNA, or protein, which ultimately leads to the diagnosis of the disease. Having an individual’s genomic information can be significantly useful for developing drugs. These days, it’s common for physicians to use a trial and error strategy until they find the treatment that is most effective for their patient, whereas with personalized medicine, we can:

  • Specifically, formulate a treatment for an individual and have insight into how their body will respond to the drug.
  • Use detailed information of the person  genotype to decide the treatment prescriptions, which will be more cost-effective and accurate.
  • Shift the emphasis in medicine from reaction to prevention.
  • Direct the selection of optimal therapy and reduce trial-and-error prescribing.
  • Help avoid adverse drug reactions.
  • Improve the quality of life.
  • Reveal additional or alternative uses for medicines and drug candidates.
  • The decrease in the overall cost of health care due to small and fast trials.

Studies that focus on a single person are known as N-of-1 trials, where enough genomic data of an individual is collected. This data provides the blueprint for the production of various proteins in the body that may have an important role in drug development for one of the several reasons, including the following:

  • The protein plays a role in breaking down the drug.
  • It helps with the absorption or transportation of the drug.
  • The protein that is the actual target of the drug.
  • It has some role in a series of molecular events triggered by the drug.

 

When researchers compare the genomes of individuals taking the same drug, they may discover that a set of people who share a certain genetic variation also share a common treatment response, such as:

  • A greater risk of side effects
  • Severe side effects at relatively low doses
  • The need for a higher dose to achieve a therapeutic effect
  • No benefit from the treatment
  • A greater or more likely benefit from the treatment
  • The optimal duration of treatment

In N-of-1 trials, the appropriate crossover designs, in which different interventions are administered to the same person alternately (possibly with ‘wash-out’ periods in between to allow the drugs’ effects to wear off) would also enable experimenters to compare the effect of different drugs in the same person.

Well-designed N-of-1 trials could be useful in the early stages of clinical drug development and for studies investigating the safety and appropriate dosages of drugs. Currently, phase I and II clinical trials usually involve giving different amounts of an FDA-approved drug to a small group of healthy volunteers.

FDA’s (U.S. Food and Drug Administration) role is to ensure the accuracy of genetic tests, many of which are acquired from the next generation sequencing (NGS), that poses novel regulatory issues for FDA. Recognizing these challenges, FDA is working out an optimum regulatory platform, by issuing discussion papers and holding workshops that will encourage innovation while ensuring accuracy. In addition, FDA has created precisionFDA, a community research and development portal that allows testing, piloting, and validating existing and new bioinformatics approaches to NGS process.

There are still various barriers to bringing N-of-1 trials mainstream, such as:

  • Regulatory agencies, researchers, and physicians are wary of moving away from classical clinical trials.
  • Pharmaceutical companies tend to focus on drugs that are likely to be used by thousands or millions of people.
  • Tailoring treatments to patients is costly as there is a lot of work to be done on biomarkers, monitoring devices, study designs and data analysis methods.

The fact remains still that these well-designed trials could save the millions of dollars that are spent on inappropriate interventions, the management and treatment of persistent or recurring diseases, and on conventional phase III trials. And the best part is that the researchers, as well as doctors, are interested in exposing people’s unique characteristics at the molecular level to deduce better alternatives to the already existing treatment procedures.  Also, cheap and efficient devices that collect health data are becoming available along with the increasing support of the governments and life-sciences funding bodies worldwide. All we require is a team effort by innovators, entrepreneurs, regulators, payers, and policymakers to overcome the barriers and move personalized medicine forward.

References-

http://www.personalizedmedicinecoalition.org/Userfiles/PMC-Corporate/file/pmc_the_case_for_personalized_medicine.pdf

 

https://en.wikipedia.org/wiki/Personalized_medicine

 

http://www.fda.gov/ScienceResearch/SpecialTopics/PrecisionMedicine/default.htm

 

http://www.mayoclinic.org/healthy-lifestyle/consumer-health/in-depth/personalized-medicine/art-20044300

 

http://www.nature.com/news/personalized-medicine-time-for-one-person-trials-1.17411

 

PERSONALIZED MEDICINES: TAILORED TO FIT ‘U’

Imagine, next time when you visit your doctor for treatment, he asks questions like –where do you live and what do you do, in addition to symptoms; before prescribing you a medicine. And ‘YES’ everything is official about it! Maybe because he wants to find the medicine that ‘FITS’ you the best. Here we are talking about the concept of Personalized Medicines wherein “one drug fits all” approach in combination with Pharmacogenomic research can evolve into an individualized approach to therapy where optimally effective drugs are matched to a patient’s unique genetic profile.

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