Biological biomarkers are features that can be quantified accurately in biological fluids or tissues. They serve as indicators to detect the first appearance of a disease, the subtype of a disease (severe or mild), or the susceptibility to a specific pathology.
Some biomarkers can be used as a tool during the clinical development of a new therapeutic approach. They enable measuring the efficacy of a new drug and selecting the patients who will most benefit from a therapy. These types of biomarkers are therapeutic orientation tools called “companion biomarkers”.
Some companion biomarkers allow monitoring the appearance and progression of a disease or treatment efficacy. They therefore have prognostic value. Other biomarkers can be used to stratify patients into subgroups, and they may help to determine the best treatment type for patients with respect to “personalized medicine, one of the major challenges of tomorrow’s medicine.
Personalized medicine is a concept based on findings that a given drug may cause different reactions in different patients, and that some drugs are effective in a given patient but not in another. Therefore, patients are treated according to their specific genetic profile, environmental considerations, and lifestyle. The promises of personalized medicine are many, including the optimization of pharmacological treatments and reduction of side effects, as well as significant economic effects. Personalized medicine will concern all patients in the long run.
Biomarkers are therefore part of a strategic and economic context, expected to play a determining role within the next few years. However, although many biomarkers have been already identified at this time, very few have been marketed.