Blood test could personalize chemo breaks for advanced colon cancer

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Histologically proven diagnosis of RAS WT or mutant, MSS, BRAFV600E non-mutated colorectal cancer. * Left side or rectal cancer * An unresectable metastatic colorectal cancer not previously treated with chemotherapy for metastatic disease. * At least one measurable lesion according to RECIST criteria version 1.1. * Age ≥ 18 years. * ECOG PS ≤ 1 * Neutrophils ≥ 1.5 x 10\^9/L, Platelets ≥ 100 x 10\^9/L, Hb \> 9 g/dl. * Total bilirubin ≤ 1.5 time the upper-normal limits (UNL) and ASAT (SGOT) and/or ALAT (SGPT) ≤ 2.5 x UNL, or 5 x UNL in case of liver metastases, alkaline phosphatase ≤ 2.5 x UNL, or 5 x UNL in case of liver metastases. * Creatinine clearance \> 50 mL/min or serum creatinine ≤ 1.5 x UNL. * The patient's urinary protein is ≤ 1+ on dipstick or routine urinalysis. * Adequate coagulation function \[International Normalized Ratio (INR) ≤1.5 and Partial. Thromboplastin Time (PTT) or activated PTT (aPTT) ≤1.5 x ULN. * Written informed consent. Exclusion Criteria: * Right side colon cancer * First-line chemotherapy +/- biologic agents for mCRC before C1 * Radiotherapy to any site within 4 weeks before C1 * Adjuvant oxaliplatin-based treatment completed less than 6 months before relapse. * Treatment with any investigational drug within 30 days prior to C1 * Known allergy to any of the study treatment components. * Dihydropyrimidine dehydrogenase (DPD) deficiency. * Documented and/or symptomatic brain or leptomeningeal metastases. * Patient with active infection, symptomatic congestive heart failure, unstable angina pectoris, symptomatic or poorly controlled cardiac arrhythmia, uncontrolled thrombotic or hemorrhagic disorder, or any other serious uncontrolled medical disorders in the opinion of the investigator. * Uncontrolled or poorly controlled hypertension despite standard medical management. * Severe renal or hepatic failure * Serious or non-healing wound, ulcer, or bone fracture within 28 days prior to C1 * Other co-existing malignancies or malignancies diagnosed within the last 3 years with the exception of basal and squamous cell carcinoma or cervical cancer in situ. * Major surgical procedure, open biopsy, or significant traumatic injury within 28 days prior to study treatment start. * Infection with the human immunodeficiency virus. * Symptomatic peripheral neuropathy grade 1 according the NCI CTC. * Acute or subacute bowel obstruction or history of chronic diarrhea, which is considered clinically significant in the opinion of the investigator. * Chronic antiplatelet therapy, including aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs, including ibuprofen, naproxen, and others), dipyridamole or clopidogrel, or similar agents. Once-daily aspirin use (maximum dose 325 mg/day) is permitted. * Pregnant or lactating women. * Patient with active psychiatric illness or social situation that would severely limit compliance with study requirements.