Precision medicine, also known as personalised medicine, is an approach to developing safer novel therapeutics that integrate genomics and big data (genetic, clinical, molecular, diagnostic and environmental data) to detect pathogenic events at the genome level, writes Lara Bartlett.
Tailor medicines to patients
Biologics, vaccines and highly selective NCEs are matched with disease targets validated by human genetics, to tailor medicines to patients.
A human has 99.9% genetic similarity to the next human, 96% genetic similarity to a chimpanzee, 90% genetic similarity to a cat, and 60% genetic similarity to a chicken, and a banana.
Fruit fly protein sequences have mammalian homologs while almost 75% of known human disease genes have a distinguishable match in the genome of the fruit fly.
Evidently, all species have a common ancestor, and therefore share multiple genome components. The individual genes operate collectively and manifest themselves in strikingly distinctive forms and divergent species by casting much of the same set of genes programmed with environmental and epigenetic factors to express as precise progressions and integrated patterns in health and disease[i].
Most global health systems established in the post-Second World War era are reactive. Patients generally had to wait until the onset of disease until they could seek medical diagnosis and treatment.
Patient management decisions
Though physicians have considered behavioural, environmental and genetic factors when making patient management decisions for years, 'genetic' information has typically consisted of self-declared ethnic, race and family history data.
The result is a standard one-size-fits-all, correlated with a trial-and-error approach to treatment, based on statistical averages derived from broad population testing.
However, different people respond differently to the same medication. On average, a prescription drug works in less than half of patients taking it, while others experience no response or unpredictable or severe adverse effects.
Dr Roses, a pioneering geneticist who broke new ground by discovering a genetic link to Alzheimer’s disease, stated in 2003: "Most drugs work in fewer than one in two patients mainly because the recipients carry genes that interfere in some way with the medicine[ii].”
Scientists still don’t entirely understand the role that genetic and environmental factors play in the development of diseases such as cancer, diabetes or COPD.
Sequencing of human genome
However, the sequencing of the human genome and rapid advances in pharmacogenomics have allowed researchers to link a growing number of diseases to particular genes.
Scientists have been making great strides in mapping the molecular pathways by which a change in a gene expresses as a disease, allowing physicians to develop better disease prevention, more accurate diagnosis and customised treatment and dosage.
Source: PMC Coalition Factsheet[iii]
The factors responsible for differences in drug response are myriad and complex, with direct or indirect impacts. The key variables are:
- genetically inherited factors (it is estimated that 80% of rare diseases have a genetic origin) [iv];
- environmental factors such as chemical and radiation exposure;
- physiological factors such as gender, age, pregnancy, liver and kidney function, and nutrition;
- lifestyle factors such as exercise, alcohol consumption, and smoking.
As a cornerstone of precision medicine, pharmacogenomics studies drug response based on genetic data and allows the assessment of given variants that determine an individual’s drug response.
The drug response of an individual patient is characterised by the pharmacokinetic and pharmacodynamic properties of prescription drugs, and by polymorphisms in drug-metabolising enzymes and transporters in individuals, influencing the efficacy and toxicity of the medication.
Varied allele frequencies in the genes of drug-metabolising enzymes, as well as transporters, have been observed in different populations[v].
KVALITO has numerous consultants working on the Novartis Kymriah project. Kymriah is a medication for the treatment of B-cell acute lymphoblastic leukaemia (ALL) which utilises the body’s T cells to fight cancer (adoptive cell transfer).
In August 2017, this became the first FDA-approved treatment to integrate a gene therapy step in the United States.
KVALITO Consulting Group supports its clients in personalised medicine in many areas:
- Governance and process excellence;
- Supply chain and chain of identity;
- Quality and compliance;
- Program and change management;
- Transformation.
References
[i] Pasipoularides A. (2017). Genomic translational research: Paving the way to individualized cardiac functional analyses and personalised cardiology. International journal of cardiology, 230, 384–401. https://doi.org/10.1016/j.ijcard.2016.12.097
[ii] https://www.independent.co.uk/news/science/glaxo-chief-our-drugs-do-not-work-most-patients-5508670.html
[iii] http://www.personalizedmedicinecoalition.org/Userfiles/PMC-Corporate/file/pmc_age_of_pmc_factsheet.pdf
[iv] Dolsten M., Søgaard M. Precision medicine: an approach to R&D for delivering superior medicines to patients. Clin Transl Med. 2012;1:7
[v] Ahmed, S., Zhou, Z., Zhou, J., & Chen, S. Q. (2016). Pharmacogenomics of Drug Metabolizing Enzymes and Transporters: Relevance to Precision Medicine. Genomics, proteomics & bioinformatics, 14(5), 298–313. https://doi.org/10.1016/j.gpb.2016.03.008
Author: Lara Bartlett, digital communications manager, KVALITO