Abstract

Analysing Circulating Tumor DNA in Clinical Trials – Today and in Future

Arndt Schmitz, Head/Senior Scientist, Bayer Schering Pharma AG

BAYER experiences with analysing 2,000 samples in our clinical trials with the most sensitive technique available will be reported. This might lead to companion diagnostics, where prescription of a therapeutics is only indicated if a mutation is found using a specific assay. Besides digital PCR, there are other PCR based approaches with similar sensitivity. We will present  our own translational medicine results, how to quantify human DNA in a few microliter blood of xenografted mice. We also were able to identify in prostate cancer blood samples mutation conferring acquired resistance to standard of care therapeutics. While digital PCR is very sensitive, it has limited multiplexing capabilities. In contrast, NGS techniques are by design multiplex but hardly sensitive enough for ctDNA analysis.  We will discuss new technical developments how to overcome this. Finally, scenarios will be discussed, which analytical technique is the most appropriate for a patient at each stage over the course of the disease.