This study investigates the progression-free survival in patients with metastatic colorectal carcinoma, a type of cancer that has spread from the colon or rectum to other parts of the body. The purpose of this study is to compare two treatment arms: one receiving an investigational medication combined with a chemotherapy regimen called FOLFIRI, and the other receiving a placebo with FOLFIRI. FOLFIRI is a combination of three drugs: 5-fluorouracil, leucovorin, and irinotecan. The study aims to see which treatment helps patients live longer without their cancer worsening.

Participants will be randomly assigned to one of the two study arms. In addition to the main treatments, a subset of patients will undergo pharmacokinetic evaluations to understand how irinotecan, one of the chemotherapy drugs, is processed in the body. The study will also explore potential links between certain biomarkers found in blood and tissue samples and the clinical benefits observed in patients.

• Who can participate: Adults aged 18 and older with metastatic colorectal cancer that has spread to other parts of the body. Participants should not have received prior treatment with FOLFIRI and must meet specific health criteria.
• Study details: Participants will be randomly assigned to receive either the investigational medication with FOLFIRI or a placebo with FOLFIRI. A placebo is an inactive substance that looks like the investigational medication but does not contain any medicine. Some patients will also have additional tests to study how the body processes one of the chemotherapy drugs, irinotecan.