TINzaparin Prophylaxis in Patients With Metastatic Colorectal Cancer

Patients with metastatic colorectal cancer (mCRC) who are scheduled to receive systemic cancer therapy have an increased risk for venous thromboembolic (VTE) events compared with the general population. PROTINCOL is a randomized, open label, non placebo-controlled, low intervention, and phase III clinical trial that will recruit patients with mCRC. The study hypothesizes that prophylaxis with Tinzaparin could prevent the appearance of symptomatic and incidental VTE. All patients will receive the first-line anticancer treatment deemed more appropriate according to the physician criteria. Enrolled patients are randomized in a 1:1 ratio (stratifying by BRAF/RAS, resection of primary tumor, and anti-angiogenic first-line treatment) to: control arm (no interventions related to VTE risk and no placebo) or experimental arm (prophylactic Tinzaparin at a fixed dose of 4500 IU/day in patients with up to 80kg, 6000 IU/day for those between 80-100 kg, or 8000 IU/day for those \>100kg). Treatment is scheduled for a maximum period of 4 months. Treatment could be stopped earlier in case of unacceptable toxicity, patient consent withdrawal, physician criteria or end of study. Patients will undergo tumor and VTE assessments according to standard clinical practice. The main objective of the study is to evaluate the efficacy of tinzaparin for the prevention of symptomatic or incidental VTE events. Secondary objectives include the associations between VTE events and tumor characteristics (i.e. laterality, RAS/BRAF mutations) or management (i.e. surgery or treatment with anti-angiogenic or anti-EGFR agents), cancer-specific survival outcomes, safety, the incidence of bleeding events, and patient-reported quality of life. The trial includes also a translational exploratory analysis to assess the predictive value of risk assessment models and genetic risk scores, their evolution through the study and microsatellite instability or other biomarkers.