Abstract

Blood-based Biomarker Assays for Personalised Tumour Therapy

Thomas Krahn, Head of Global Biomarker Research Department, Bayer Pharma Ag

Obtaining tumour tissue from cancer patients for diagnosis and biomarker assessment for patient stratification is challenging. Blood based biomarker e.g. free circulating tumour DNA (ctDNA) and circulating tumour cells (CTCs) may represent an attractive alternative as a “liquid biopsy” providing real-time information about the patient’s current disease state as well as response to treatment. Analysis of ctDNA applied in clinical trials in different types of cancer has been demonstrated to be a sensitive and specific biomarker. Capturing CTCs from blood is a major challenge that still needs improvement. We are exploring technologies to capture larger amounts of tumour cells and to use their molecular profile to predict response to treatment in early clinical trials. We will present data of a study comparing different CTC capturing technologies. For optimal comparison, CTC preparations from the same patient were used. The required high amounts of sample aliquots and CTCs were obtained e.g. by apheresis.  Today’s standard, the CellSearch® system by Veridex was performed and compared with other antigen-based methods and antigen independent methods. Downstream analysis of the isolated CTCs is performed by highly sensitive protein analysis technologies. Limited capture efficiency is tried to be tackled by cultivation of CTCs. Examples of predictive biomarkers based on CTCs capturing and subsequent molecular analysis will be shared and discussed.