5-fluorouracil + antineoplaston A10 + antineoplaston AS2-1

This is a combination therapy consisting of three agents: 5-fluorouracil, antineoplaston A10, and antineoplaston AS2-1. **5-Fluorouracil (5-FU)** is a classic chemotherapeutic agent that acts as an anti-metabolite, inhibiting thymidylate synthase and thereby blocking DNA synthesis in rapidly dividing cells[8]. **Antineoplastons** are experimental cancer therapies developed from naturally occurring peptides and amino acid derivatives found in human blood and urine. Antineoplaston A10's active component is 3-phenylacetylamino-2,6-piperidinedione; it may regulate neoplastic growth without significantly affecting normal cell growth[1][5]. **Antineoplaston AS2-1** is a mixture of phenylacetate and phenylacetylglutamine (4:1 ratio), which are degradation products of A10. It has been shown to inhibit the incorporation of L-glutamine into tumor-cell proteins (leading to G1 cell cycle arrest), inhibit RAS oncogene expression, activate p53 tumor suppressor gene pathways, induce differentiation, apoptosis, and may normalize hypermethylation at promoter regions of silenced tumor suppressor genes[7][9][10]. The combination has been studied as adjuvant therapy after hepatectomy for colorectal metastases to the liver; clinical trials suggest possible benefit in cancer-specific survival with manageable toxicity profiles[1][3].