Irinotecan is a topoisomerase inhibitor used to treat metastatic carcinoma of the colon or rectum and pancreatic adenocarcinoma. It is a water-soluble analogue of camptothecin, which is extracted from the Chinese tree Camptotheca acuminate.
- Mechanism
- Curator reviewed · 8 references
DNA topoisomerase I is a nuclear enzyme that ensures proper DNA topology during replication and transcription. It relieves torsional strain in the DNA double helix during replication and transcription by creating reversible single-strand breaks.
Upon administration, irinotecan is converted into its active metabolite, SN-38, by carboxylesterase in the liver and gastrointestinal tract. Irinotecan and SN-38 both inhibit DNA topoisomerase I, acting on the S and G2 phases of the cell cycle. Irinotecan and SN-38 bind to the topoisomerase I-DNA complex and prevent the religation of single-strand breaks. The ternary complex formed by topoisomerase I, DNA, and either irinotecan or SN-38 interferes with the moving replication fork, inducing replication arrest and lethal double-stranded breaks in DNA. Because double-stranded breaks cannot be efficiently repaired by mammalian cells, apoptosis of cancer cells occurs.
- Primary indication
- Irinotecan is indicated for the treatment of: - Metastatic carcinoma of the colon or rectum as first-line treatment in combination with fluorouracil and leucovorin. - Metastatic carcinoma of the colon or rectum whose disease has...Curator reviewed · 15 structured indications
- Formula / weight
- C33H38N4O6 · 586.678 g/mol (avg)
- First approval
- Canada, 2003 · United States, 1996 · European Union, 2020
- Also known as
- (S)-4,11-diethyl-4-hydroxy-3,14-dioxo-3,4,12,14-tetrahydro-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinolin-9-yl 4-(2-(5-(3-(2,4-dihydroxy-5-isopropylphenyl)-5-hydroxy-4H-1,2,4-triazol-4-yl)-1H-indol-1-yl)ethyl)piperidine-1-carboxylate · Irinotecan lactone
- Code names
- CPT-11 · NSC-728073
- Brand names
Resolves to
UWKQSNNFCGGAFS-XIFFEERXSA-NSMILESCCC1=C2CN3C(=CC4=C(COC(=O)[C@]4(O)CC)C3=O)C2=NC2=CC=C(OC(=O)N3CCC(CC3)N3CCCCC3)C=C12What you can answer from here — as of September 19, 2026
Which drugs share a target with Irinotecan, and which of those have an active Phase 3 trial?
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