The trial will consist of both a clinical and translational part. During the study, re-assessments (radiologic assessment, blood and QoL) will be conducted for all trial subject of the trial every 3 months. Tumor biopsies will be collected at screening (baseline sample) and in case of relapse of disease if a new tumor sample is obtained.~The objective of the re-assessments is detection of relapse either radiologically or within the translational material (blood samples with ctDNA dynamics and tumor - if available from relapses). CT scans of thorax/abdomen and/or MRI scans will be performed every 3 months within the 2 years after randomization. After the first two relapse-free years, intervals should be stretched to 6 months in the third and following years after study start. Structured follow-up for up to 60 months after randomization should be maintained for both arms.~Patients in Arm A receive additive study drug intervention (mFOLFOXIRI or mFOLFOX-6) for up to six months (12 cycles) after randomization with additional clinical and safety assessments.
This is an open-label, randomized, controlled, multicenter, phase III study with two parallel arms. Patients with metastatic colorectal cancer after definite interventional therapy of all lesions are randomized in a 2:1 fashion (favoring active therapy) to investigate the efficacy, patient reported quality of life and safety of mFOLFOXIRI/mFOLFOX-6 as additive treatment (Arm A) versus active follow-up/surveillance (Arm B).