“The optimal use of limited tissue to address the effect of MTAs on multiple targets must be determined. Furthermore, routine sample processing and preservation protocols may be inadequate…biopsy tissue many need immediate and tailored processing.”
(Bruce Chabner, Kwak, 2007)
“A description of cancer in molecular terms seems increasing likely to improve the ways in which human cancers are detected, classified, monitored and especially treated.”
(Harold Varmus, The New Era of Cancer Research, Science, May 26, 2006, Vol 312) |
The diagnosis and treatment of cancer are undergoing dramatic changes as our understanding of cancer biomarkers improves, and as new targeted drugs are developed. Drug and diagnostic combinations, also known as companion diagnostics, will first be used to stratify patients in clinical trials. Once drugs are approved, these biomarker tests will then also ensure that the right patients get the right drug—and that health plans will reimburse for these expensive cancer treatments.
While some biomarker tests have been developed to guide drug treatment selection, there is growing awareness that the current classes of biomarkers are not sufficient. One major limitation of the existing classes of static biomarkers is the inability to extract functional information from dead, fixed tumor cells. Static biomarkers, such as EGRF mutation analysis or HER2 immunohistochemistry, identify drug targets but they do not reveal the complex functional circuitry of the signal transduction network downstream of the target.
Many investigators have attempted to utilize array technology and sophisticated bioinformatics tools to infer function from protein or microarray data sets derived from fixed tissue, however only functional assays on living tumor cells reveal the synthesis of this variation without the need to identify and understand every molecular variant within the network.
Ex vivo biomarkers are dynamic molecular markers, such as phosphoproteins, that are evoked from living tumor cells after removal from the patient. While ex vivo biomarkers have been utilized for single-cell, fluidic cancers, such as leukemia and lymphoma, ex vivo biomarkers in solid tumor tissue-based cancers can only become clinically available using the SnapPath™ platform. BioMarker Strategies is developing a unique ex vivo biomarker test to inform drug treatment selection for cancer patients with breast, colon, lung, pancreatic and other solid tumors.
The role of ex vivo biomarkers in drug development and utilization is more fully explained in a recent scientific review by our Chief Science Officer, Dr. Douglas Clark, who is also the Director of Cytopathology at Johns Hopkins.
|
