Spring 2006
Biomarkers Why, What & How: Relevance to Modern Medicine
Presented by Dr Gary Coulton, St Georges Hospital, London
Dr Gary Coulton, from St Georges’ Hospital, London gave a thought-provoking presentation on the relevance of Biomarkers to modern medicine. This was followed by information about the biomarker research facilities at St Georges’ Hospital, London.
Dr Coulton began his presentation by defining biomarkers as ‘anything measurable about an organism’. He highlighted their role in deciding if the beneficial effects of a new drug outweighed the toxicity and hence the need to pursue regulatory approval. Holistic, global – ‘omic’ technologies (i.e. proteomics, metabolomics, cDNA micro arrays) help in determining which biomarkers are important and which aren’t so important in terms of an organism’s response to a drug substance.
Proteomics, a study of the structural and cellular components of proteins, has a massive pipeline. This is made possible by modern techniques of protein identification such as Mass Spectrometer & 2D gel electrophoresis. Newly identified biomarkers are purified and used in the creation of specific antibodies. These are validated by ELISA assays. The proteomic approach is highly discriminatory thus an excellent basis for the involvement of these techniques in biomarker identification and selection. This is enhanced by the minimal amounts of sample required for diagnosis. Between 3 to 5 mls of serum can provide greater than 98% sensitivity and specificity. This can be useful in the early diagnosis of prostate cancer for example.
Biomarker plausibility is in three stages:
The first stage involves initial phases of research techniques such as high throughput technology, ELISA or immunoassays. The signal to noise ratio at the end of this phase is usually high.
The second stage involves collaboration with an industry partner. It involves more ELISA techniques, this time resulting in a smaller signal to noise ratio.
The third stage focuses on the development of a ‘panel-specific’ diagnostic tool, post-development quality assurance and commercialisation and then hopefully some profit for all involved.
St Georges in London has a BIOMICS technology research centre, BIOMICS I (Biological, Investigation of Molecules in Complex Systems). This unique centre specialises in Genomics, Transcriptions, Proteomics & Metabolomics technologies. Data derived from these research studies can be in the region of petabytes.
Biomarker research is the beginning of personalised medicines. Drivers for research of this sort include the varying types of litigations involving drug substances and large numbers of deaths due to adverse drug reactions. Using biological entities in drug development as opposed to chemical entities would not necessarily get drugs to the market quicker but it would provide a stronger confidence in going forward with a new drug entity.
Chinnie Nwandu