Study on the effects of metformin and cimetidine on the exposure of trifluridine/tipiracil (lonsurf) in patients with a metastatic colorectal carcinoma

Primary objectives: 1. To determine the possible drug interaction between Lonsurf and metformin on Lonsurf plasma pharmacokinetics (AUC) in patients with metastatic colorectal cancer.2. To determine the possible interaction between Lonsurf and cimetidine on Lonsurf plasma pharmacokinetics (AUC) in patients with metastatic colorectal cancer. of concomitant administration of Lonsurf with metformin and cimetidine on Lonsurf and metformin exposure.
Primary endpoints: To determine the influence of concomitant administration of Lonsurf with metformin and cimetidine on Lonsurf and metformin exposure.