Personalized medicine is a term that describes the concept that drug therapy should be tailored to each individual. So, whereas in the past drugs would be prescribed based on diseases and symptoms, personalized medicine adds the considerations of a persons genetic makeup and the proteins expressed in the disease (e.g. in cancer.)
By this method, personalized medicine aims to move from a one-drug-for everybody approach to an approach that gets the right drug, to the right person, at the correct dose.