A state of the art mCRC Patient Derived Xenograft (PDX) platform will be established

Coloforetell will utilise this discovery platform, which represents a state of the art tool in targeted therapy biomarker discovery. Data generated from PDX studies has been shown to recapitulate clinical outcomes, have utility in biomarker identification, and facilitate the individualization of patient treatment. Viably frozen tumor material for molecularly characterized mCRC PDX models (collected from patients at time of liver metastasectomy) will be provided by collaborators at the University of Turin. Towards the end of the project orthotopic PDX models will be employed as "next generation orthoxenograft mCRC PDX models"

State of the art imaging to be used to investigate the response of different PDXs to REG treatment.

Positron emission tomography (PET), using the radiotracer 18F-fluorodeoxyglucose (FDG) [FDG-PET] will be used to investigate tumour metabolism. Contrast enhanced ultrasound (CEUS) will be used to investigate tumour blood vessel response to REG treatment. Impact of REG treatment on tumour vessel proliferation, maturation and tumor cell death will be assessed by histological evaluation following treatment. Dynamic contrast enhanced- magnetic resonance imaging (DCE-MRI) will be further used to monitor REG treatment in PDX models. DCE-MRI could ultimately be used in humans to as a predictive response biomarker.

Biomarker discovery

(a) Whole exome sequencing of PDX tumors to identify predictive genetic biomarkers

(b) Reverse phase protein array of PDX tumors to identify predictive protein biomarkers or biomarker signatures

(c) Analysis of PDX molecular subtypes (based on gene expression analysis) to identify which CRC molecular subtypes best respond to REG treatment

(d) All these data will be integrated using novel systems biology approaches to best identify new predictive biomarker signatures