Last reviewed 2026-05-31 · How we verify

5-fluoro-uracil

5-fluoro-uracil is a Antimetabolite Small molecule drug developed by UNICANCER. It is currently FDA-approved for Colorectal cancer, Gastric cancer, Breast cancer. Also known as: Efudix® 5%.

5-fluorouracil is a pyrimidine analog that inhibits thymidylate synthase and gets incorporated into RNA and DNA, disrupting nucleotide synthesis and causing cell death.

5-fluoro-uracil is a small molecule inhibitor of thymidylate synthase used in chemotherapy to treat various types of cancer, including pancreatic cancer. It is administered through intravenous injection or as a cream for skin conditions such as actinic keratosis, basal cell carcinoma, and skin warts.

At a glance

Mechanism of action

5-FU is converted intracellularly to active metabolites that inhibit thymidylate synthase, blocking dTMP synthesis and DNA replication. It also incorporates into RNA, disrupting protein synthesis. This dual mechanism makes it effective against rapidly dividing cancer cells, particularly in the gastrointestinal tract and breast.

Approved indications

• Colorectal cancer
• Gastric cancer
• Breast cancer
• Pancreatic cancer
• Head and neck cancer

Common side effects

• Myelosuppression (neutropenia, thrombocytopenia)
• Mucositis
• Diarrhea
• Nausea and vomiting
• Hand-foot syndrome
• Alopecia

Key clinical trials

• Therapy Adapted for High Risk and Low Risk HIV-Associated Anal Cancer (PHASE2)
• A Study to Evaluate the Safety and Efficacy of Two Dose Levels of ONO-4578 With Opdivo®, in Combination With mFOLFOX6 and Bevacizumab Versus Standard of Care in Participants With Non-MSI-H/dMMR, PD-L1 Positive Advanced Colorectal Cancer (PHASE2)
• Targeted Therapy Directed by Genetic Testing in Treating Patients With Locally Advanced or Advanced Solid Tumors, The ComboMATCH Screening Trial (PHASE2)
• Risk-Based Therapy in Treating Younger Patients With Newly Diagnosed Liver Cancer (PHASE3)
• Individual Response to Hyperthermic Intraperitoneal Chemotherapy (HIPEC) Treatment of Peritoneal Carcinomatosis From Peritoneal Mesothelioma or Atypical Mesothelial Proliferation or From Ovarian, Colorectal, or Appendiceal Histologies (PHASE1)
• Studying Chemotherapy With or Without Panitumumab for Unresectable, Locally Advanced, or Metastatic Pancreatic Cancer Without KRAS Mutations (PHASE3)
• Testing the Addition of the Immunotherapy Drug, Pembrolizumab, to Radiation Therapy Compared to the Usual Chemotherapy Treatment During Radiation Therapy for Bladder Cancer, PARRC Trial (PHASE2)
• Adjuvant Treatment of Gastric Cancer With Chemotherapy and Chemoradiotherapy (TRACE) (PHASE2)

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• 5-fluoro-uracil CI brief — competitive landscape report
• 5-fluoro-uracil updates RSS · CI watch RSS
• UNICANCER portfolio CI

Frequently asked questions about 5-fluoro-uracil

Related

• Drug class: All Antimetabolite drugs
• Target: All drugs targeting Thymidylate synthase; RNA and DNA incorporation
• Manufacturer: UNICANCER — full pipeline
• Therapeutic area: All drugs in Oncology
• Indication: Drugs for Colorectal cancer
• Indication: Drugs for Gastric cancer
• Indication: Drugs for Breast cancer
• Also known as: Efudix® 5%

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing