Many drugs fail to have any beneficial effect in a significant proportion – in some cases more than 50 percent – of the people who take them. It’s also common knowledge that many candidate drugs fail late in their clinical development, after eating up huge amounts of time and money, because they may trigger severe adverse reactions in a proportion of patients. Adverse effects in even a very small number of patients can be sufficient to cause product withdrawal, regardless of the benefits the product offers to the majority. It is now recognized that these systemic inefficiencies, and their significant economic and health consequences, are primarily due to genetic variations between patients. And this recognition has led to the development of tools and techniques to adjust treatments according to genetic background and other individual charateristics – so-called personalized medicine, stratified medicine and similar concepts.

The underlying intent of all of these is to diagnose a condition quickly and unambiguously, and then to match the diagnosis to a specific medicine or therapy, determined in part by the patient’s particular genotype or phenotype. The preferred term for this paradigm is ‘precision medicine’, and it is being intensively pursued, at both the preclinical and clinical level. There is a belief that ineffective treatment, waste and late-stage pipeline attrition can all be addressed if precision medicine approaches are brought to the fore.