[STRENGTHS AND WEAKNESSES OF RANDOMISED CLINICAL TRIALS: EVOLVING CHANGES ACCORDING TO PERSONALIZED MEDICINE].

Randomised Controlled Trials (RCTs) represent the cornerstone of Evidence-Based Medicine (EBM). Based upon the rules of Good Clinical Practice (GCP), they offer many strengths but also present some weaknesses. The rigorous methodology used allows avoid bias related to confounding factors (through a control group), selection bias (through randomisation) and interpretation bias (through double blinding). However, patients recruited in clinical trials and study experimental conditions markedly differ from the situation in real life. Furthermore, clinical trials recruit a mix of good and poor responders, so that the average therapeutic response is most often mitigated. Clinical trials must evolve according to the new concepts of personalized medicine to become even more performing. In a near future, they must progress from a statistical analysis on large cohorts of patients to a more individualized analysis guided by patient phenotype and genotype characteristics.