Folinic acid enhances the effectiveness of 5-FU by stabilizing the bond between 5-FU and the enzyme thymidylate synthase, which is crucial for DNA synthesis. This ultimately disrupts DNA synthesis in cancer cells. Oxaliplatin, on the other hand, forms cross-links within DNA, preventing the cancer cells from replicating and causing cell death. Together, these drugs form a powerful combination that can effectively reduce tumor size and slow the progression of cancer.