PUBLIC HEALTH PROJECTS
Personalized medicine
Personalized medicine is a concept that is progressively becoming one of the major challenges
for the medicine of tomorrow. Although doctors knew that a drug prescribed for a given condition would
not always cure the patient and could possibly cause undesirable or dangerous side effects, they did
not have the means of predicting the efficacy of the drug on their patient. Precious time was lost in
finding the right treatment.
Better knowledge of pathologies and of each patient through the use of ever more precise diagnostic tests
can help physicians choose specific treatments and avoid others, when clinical symptoms are identical. Each
patient is unique and should receive a treatment that has the best chances of success.
Personalized medicine thus aims to determine homogenous sub-populations of individuals or sub-categories
of diseases to which a particular patient belongs. Each group of patients can thus receive certain families
of drugs very precisely adapted to their disease, which is a "personalization" of the treatment.
This stratification of patients or pathologies is possible by analyzing one or more combinations of
"biomarkers", through the use of diagnostic tests on laboratory samples (blood, urine, cancerous tissues, etc.).
Discovery and validation of new biomarkers are intrinsically linked to the development of personalized
medicine. Biomarkers are not a new concept. The measurement of body temperature or the concentration
of glucose in the blood are well-known examples.
The new biomarkers are molecular, biochemical or cellular parameters that can be used to pre-emptively
screen for diseases, make a precise diagnosis (for example the classification of cancers is no longer
conducted per organ but molecularly), establish prognosis, determine the most suitable treatments
(stratification of patients) and also monitor patient responses and evolution to better adapt
treatments if needed.
Development of more efficient and more targeted drugs for every disease is only possible with the discovery
of biomarkers associated with the pathologies. As such, a drug whose overall efficacy may be weak or
average for most patients, when associated biomarkers have not been measured for the patients, may be
extremely effective if it is prescribed on a population of patients selected by a diagnostic test that
utilizes these same biomarkers. For the drugs being developed there is more and more an associated
"companion" diagnostic test that is used to predict the efficacy of the drug.
This should lead to better treatment of the disease and help manage the costs of care. The biomarkers discovered and
validated will be an integral part of "companion" diagnostic tests that will be marketed in parallel
with the specifically associated therapies. Therapy and diagnosis are thus more and more indissociable,
which has given rise to the new descriptive term "theranostic".