A Study of On-treatment ctDNA Changes in Chemo-refractory Colorectal Cancer Patients

COPERNIC is an international, multicentre, single-arm study. Chemo-refractory mCRC subjects who meet all eligibility criteria will be treated with standard systemic chemotherapy (the decision about the treatment regimen being made by the treating physician) and undergo tumour assessment by standard imaging (either CT scan or MRI scan) at baseline and every 8 or 12 weeks until evidence of tumour progression. Response to treatment will be assessed by the local investigators according to the RECIST criteria version 1.1. Blinded, independent central review of the imaging scan will be carried out, this having no impact on treatment decisions thatwhich will remain the prerogative of the treating physician. Serial blood samples from study subjects will be collected at pre-defined time points for ctDNA testing. Also, archived tumour tissue from each subject will be collected. Prospective and retrospective ctDNA analyses on blood samples will be carried out, and dynamics of ctDNA will be correlated with treatment outcomes prognosis.