Perspective
Personalised Medicine What happens when one size does not fit all?
T
he first race-based combination pre‐
essential tool in medicine. The example of Ge‐
scription drug, Hydralazine-plus-ni‐
fitinib: Researchers observed that Japanese pa‐
trate is used in the treatment of
tients over-express a certain protein: Epidermal
congestive heart failure. Among African Amer‐
Growth Factor Receptor (EGFR). Gefitinib
icans, life expectancy of those with heart failure
works by inhibiting EGFR and consequently
is increased using this combination drug,
decreasing its activity. EGFR is a protein found
whereas white Americans respond less effect‐
in both normal cells and cancer cells. However,
ively to the drug. Another drug, Gefitinib, used
its over-expression can be a result of mutations.
in the treatment of certain cancers such as breast
efficacy and minimise side effects. However, in
“Therapeutics would be much easier if if the same dose of drug always produced the same response.”
reality, genetic and lifestyle variations between
These mutations can cause EGFR to be con‐
individuals, play a major role in how an indi‐
tinuously activated, leading to uncontrolled cell
vidual responds to a given drug. Personalised
division, one of the hallmarks of cancer. Using
medicine and Pharmacogenomics testing offer
this information, patients can be prescribed
the possibility of more precise therapeutics for
more personalised targeted therapy.
and lung cancer is more effective in Japanese than American patients as evidenced by clinical trials. Therapeutics would be much easier if the same dose of drug always produced the same response. Enabling research to improve drug
several drugs and disorders. Personalised medi‐
The use of pharmacogenomic testing can
cine (precision medicine), is the concept of in‐
help healthcare providers determine the best
dividualising drug therapy using the genomic
medication for a patient. These tests can help
information of an individual. Pharmacogen‐
determine the effectiveness, optimum dose and
omics, also called pharmacogenetics or drug-
possible side effects of a drug. There are several
gene testing, focuses on how an individual’s
pharmacogenomic tests currently in use for this
genes affect their response to medication. This
purpose. One of these is the CYP2D6 genetic
is a field of intense research activity, rapid pro‐
test, which tests for variants of this gene, pre‐
gress and high expectations. However, proving
dicting how patients will respond to different
these tests add to present health diagnosis and
medications for the treatment of a variety of
improve patient outcomes remains a challenge.
conditions like breast cancer, depression and
As researchers continue to look further into
anxiety disorder. Information from this test
disease pathways and how drugs affect them,
shows how a patient will metabolise a given
personalised medicine has the potential to in‐
drug, which can affect their responsiveness to
crease the quality of clinical care and become an
it. 23
