Prospective CiRculating prOstate Cancer Predictors in HighEr Risk mCRPC studY

The study will construct a multi-center clinical database of men before and after treatment with abiraterone acetate, enzalutamide, and taxane chemotherapy, and will comprehensively analyze CTC DNA for copy gains/losses and whole exome sequencing for acquired mutations, CTC RNA for AR-variants and evidence of epithelial plasticity, and plasma circulating tumor DNA (ctDNA) for whole exome sequencing. Significantly, the investigators will pair the presence of key proposed circulating biomarkers of treatment resistance with patient outcomes on these systemic therapies for the purpose of developing predictive biomarkers that may have direct clinical utility in guiding choice of therapies. It is proposed that specific AR-v's (i.e. AR-v7), biomarkers of epithelial plasticity, and microtubule interacting protein variants will convey docetaxel resistance and be enriched in men failing abiraterone acetate or enzalutamide, while other AR genomic events (AR amplification, AR-v567es, AR mutations, GR overexpression) will be responsive to taxane chemotherapy. This work represents a first-in-field comprehensive analysis of CTC molecular profiles for the development of a CTC molecular taxonomy of mCRPC.