Abstract : The cost of pharmacotherapy is increasing in the health care budget. The pharmaceutical industry is facing the exhaustion of medications that are largely prescribed and have a high profitability (blockbusters). Because of patient heterogeneity, there is a great interindividual variability of the responses to drug therapy. Thus, it is essential to better detect potential «good responders» to avoid waste of resources resulting from the prescription of expensive drugs to poor responders. The development of personalized medicine, or precision medicine, certainly offers opportunities to the pharmaceutical industry, but also exposes it to new big challenges.