CAPETERO-500 Tablets CAPETERO-500 contains Capecitabine, an orally administered prodrug of 5-fluorouracil (5-FU). It undergoes a three-step enzymatic conversion to 5-FU, with the final activation step catalyzed by thymidine phosphorylase, an enzyme present at significantly higher levels in tumor tissues compared to normal tissues. The generated 5-FU inhibits thymidylate synthase, blocking DNA synthesis and cell division. It is indicated for the treatment of metastatic colorectal cancer, adjuvant treatment of stage III colon cancer, and locally advanced or metastatic breast cancer (either as monotherapy or in combination with docetaxel).