Measurable parameters for customized therapies
In order to make it possible to measure healthy and pathological processes in the body, medical scientists use 'biomarkers' as benchmarks. These are measurable parameters that are detected either by physical methods (e.g. by measuring blood pressure), or by using methods of biochemistry or molecular biology (to measure e.g. carbohydrates, enzymes or receptor molecules in the blood or tissue). Measuring biomarkers provides valuable information on certain metabolic processes: the more specifically a biomarker is connected with a disease process, the more precise is the information that can be derived.
The search for suitable biomarkers is an important factor in drug development at Bayer. These indicators make it possible to detect and classify pathological processes and to monitor the course of therapy. Biomarkers help provide early indications on how likely it is that there will be side effects or how high the risk is that a disease will progress further in individual patients (patient stratification). Furthermore, biomarkers open the door to personalized medicine. The detection of a biomarker makes it possible to assess a patient's individual success prospects with regard to the respective therapy.
Tracking down suspicious proteins
In its search for suitable biomarkers, Bayer uses what is known as multiplexing to detect proteins that are known to be involved in the disease process. Serial tests are conducted on patients' blood or urine samples to look for 60 to 80 of these proteins. Antibodies targeting these proteins are marked with a fluorescent dye, which is released when the antibody binds to the antigen, thus signaling the latter's presence. This enables the researchers to measure whether and how the drug influences the release or activity of these proteins and, if so, how these changes interact with the disease process.
While certain specific proteins are detected by multiplexing methods, researchers use DNA chips to get a picture of the messenger RNA (mRNA) levels that have formed in a cell. Valuable information on suitable biomarkers can be gained from the ways in which the mRNA level in a diseased cell (e.g. a cancer cell) deviates from that of a healthy cell.
A person's genome also plays an important role in the genesis of diseases and the effects that drugs have (see pharmacogenetics ). The genetic information is therefore also important for biomarker research.