Pharmacogenomics and Biomarkers
Scientifically, personalized medicine is known as pharmacogenomics (drugs combined with genes), or how genetic differences in individuals affect the way people respond to drugs. Biomarkers are biological molecules found in blood, body fluids, tissues or the tumour itself. Biomarkers can be a sign of a normal/abnormal process, or of a condition or disease. For example, blood pressure is widely accepted as a biomarker because a correlation between elevated blood pressures and adverse cardiovascular outcomes has been demonstrated.
Biomarkers can be divided into the categories of predictive or prognostic. A prognostic biomarker is associated with the likelihood of an outcome such as survival, response and recurrence.
A predictive biomarker is a biomarker that is present prior to an event occurring and which predicts that outcome. A predictive biomarker can be either positive or negative. For example, the KRAS oncogene can be considered a negative predictive biomarker for response to treatment with the EGFr (epidermal growth factor receptor) inhibitor class of drugs since it can identify which patients are unlikely to respond to treatment with an EGFr inhibitor.
Using Biomarkers
In recent years, significant advances in our understanding of human biology have yielded novel drug targets that may impact disease. Typically, early clinical trials test a drug target’s safety and tolerability. The efficacy of a drug is typically not tested until later stages in development.
Researchers may now be able to use pharmacogenomics to improve the efficiency of drug development. Using biomarkers, researchers can explore how a drug works in the body, allowing earlier decisions on whether to advance molecules in clinical trials.
Biomarkers may also be used to diagnose disease and for patient selection. As research continues, our understanding of the role biomarkers can play in the management of disease areas such as cancer, cardiology, neurology, metabolic, autoimmune and inflammatory diseases has evolved.